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Dissertations / Theses on the topic 'Photon detection'
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Zhao, Kai. "III-V single photon avalanche detector with built-in negative feedback for NIR photon detection." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p3320151.
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Thesis (Ph. D.)--University of California, San Diego, 2008.<br>Title from first page of PDF file (viewed September 22, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Loschke, Kyle W. "Photon signatures for standoff bomb detection." Thesis, Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/894.
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Piyankarage, Viraj Vishwakantha Jayaweera. "Uncooled Infrared Photon Detection Concepts and Devices." Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/phy_astr_diss/30.
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This work describes infrared (IR) photon detector techniques based on novel semiconductor device concepts and detector designs. The aim of the investigation was to examine alternative IR detection concepts with a view to resolve some of the issues of existing IR detectors such as operating temperature and response range. Systems were fabricated to demonstrate the following IR detection concepts and determine detector parameters: (i) Near-infrared (NIR) detection based on dye-sensitization of nanostructured semiconductors, (ii) Displacement currents in semiconductor quantum dots (QDs) embedded dielectric media, (iii) Split-off band transitions in GaAs/AlGaAs heterojunction interfacial workfunction internal photoemission (HEIWIP) detectors. A far-infrared detector based on GaSb homojunction interfacial workfunction internal photoemission (HIWIP) structure is also discussed. Device concepts, detector structures, and experimental results discussed in the text are summarized below. Dye-sensitized (DS) detector structures consisting of n-TiO2/Dye/p-CuSCN heterostructures with several IR-sensitive dyes showed response peaks at 808, 812, 858, 866, 876, and 1056 nm at room temperature. The peak specific detectivity (D*) was 9.5E+10 Jones at 812 nm at room temperature. Radiation induced carrier generation alters the electronic polarizability of QDs provided the quenching of excitation is suppressed by separation of the QDs. A device constructed to illustrate this concept by embedding PbS QDs in paraffin wax showed a peak D* of 3E+8 Jones at ~540 nm at ambient temperature. A typical HEIWIP/HIWIP detector structures consist of single (or multiple) period(s) of doped emitter(s) and undoped barrier(s) which are sandwiched between two highly doped contact layers. A p-GaAs/AlGaAs HEIWIP structure showed enhanced absorption in NIR range due to heavy/light-hole band to split-off band transitions and leading to the development of GaAs based uncooled sensors for IR detection in the 2 5 μm wavelength range with a peak D* of 6.8E+5 Jones. A HIWIP detector based on p-GaSb/GaSb showed a free carrier response threshold wavelength at 97 µm (~3 THz)with a peak D* of 5.7E+11 Jones at 36 μm and 4.9 K. In this detector, a bolometric type response in the 97 - 200 µm (3-1.5 THz) range was also observed.
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AMARAL, GUSTAVO CASTRO DO. "FPGA APPLICATIONS ON SINGLE PHOTON DETECTION SYSTEMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=24276@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR<br>CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO<br>PROGRAMA DE EXCELENCIA ACADEMICA<br>Apesar da alta sensibilidade alcançada por Fotodetectores comercialmente disponíveis, a implementação de circuitos de gerenciamento é capaz de fortalecer a robustez das medidas, criando um aparato com mais recursos em aplicações específicas. Duas aplicações práticas dessa hipótese são apresentadas em contextos diferentes, Criptografia Quântica e Monitoramento de Fibras Ópticas fazendo uso da plataforma FPGA.<br>Despite the high sensitivity reached by Photon Detectors so far, the implementation of a background managing system often enforces the robustness of measurements thus creating a resourceful apparatus for specific applications. In this document, the management tools offered by Software Defined Hardware (SDHs) is put to test. By associating the power of FPGAs and Photon Detectors, enhanced measurement stations were assembled. Two different applications, a Bell State Projection Analysis Station and a Photon Counting Optical Time Domain Reflectometry (v-OTDR)Automatic Setup, are presented. Even though both experiments involve the detection of single photons, the background technologies differ drastically.
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Maccarone, Aurora. "Single-photon detection techniques for underwater imaging." Thesis, Heriot-Watt University, 2016. http://hdl.handle.net/10399/3287.
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This Thesis investigates the potential of a single-photon depth profiling system for imaging in highly scattering underwater environments. This scanning system measured depth using the time-of-flight and the time-correlated single-photon counting (TCSPC) technique. The system comprised a pulsed laser source, a monostatic scanning transceiver, with a silicon single-photon avalanche diode (SPAD) used for detection of the returned optical signal. Spectral transmittance measurements were performed on a number of different water samples in order to characterize the water types used in the experiments. This identified an optimum operational wavelength for each environment selected, which was in the wavelength region of 525 - 690 nm. Then, depth profiles measurements were performed in different scattering conditions, demonstrating high-resolution image re-construction for targets placed at stand-off distances up to nine attenuation lengths, using average optical power in the sub-milliwatt range. Depth and spatial resolution were investigated in several environments, demonstrating a depth resolution in the range of 500 μm to a few millimetres depending on the attenuation level of the medium. The angular resolution of the system was approximately 60 μrad in water with different levels of attenuation, illustrating that the narrow field of view helped preserve spatial resolution in the presence of high levels of forward scattering. Bespoke algorithms were developed for image reconstruction in order to recover depth, intensity and reflectivity information, and to investigate shorter acquisition times, illustrating the practicality of the approach for rapid frame rates. In addition, advanced signal processing approaches were used to investigate the potential of multispectral single-photon depth imaging in target discrimination and recognition, in free-space and underwater environments. Finally, a LiDAR model was developed and validated using experimental data. The model was used to estimate the performance of the system under a variety of scattering conditions and system parameters.
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Söderstrand, Alexander. "Models of superconducting nanowire single-photon detection." Thesis, KTH, Fysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-217346.
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Stensson, Katarina. "Generation and detection of non-classical photon states." Licentiate thesis, KTH, Tillämpad fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-228058.
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This thesis intends to familiarize the reader with the concepts of photon statistics and correlations in quantum optics. Developing light sources that emit quantum states is central for the realization of quantum technologies. One important step in characterizing these sources is the measurement of field fluctuations and correlations, by coincidence measurements. The expectation value of a coincidence measurement, a simultaneous measurement of two intensities (or, more general, four fields), is represented by the fourth-order correlation function. The value of the correlation function, at zero delay between the detection of two photons, reveals important properties of the state to which they belonged, for example the fluctuations of the photon number. Since predictability is important for many applications, light sources emitting single photons are also characterized by the indistinguishability of consecutively emitted photons, or of two photons from separate emitters. In paper I we investigate blinking behaviour in quantum emitters, and its effect on the interference pattern and photon statistics with photons from two separate emitters. Blinking refers to an emitters transition into a non-emitting state, and subsequent transition back to an emitting state. We show that blinking can not be treated as linear loss, when measuring the fourth-order correlation function for two emitters in a Hong-Ou-Mandel setup. In general, a measurement of the fourth-order correlation function is robust to loss, which makes it a very practical tool. However, the relation between recorded coincidence counts and the correlation function is only direct in the limit of zero detection efficiency, and depends on the detection system. In paper II, we show that by adding a variable attenuation in the beam path, we can trace back to the ''true'' value of the correlation function at zero quantum efficiency. This method improves accuracy in correlation measurements by decreasing a systematic error at the expense of an increased statistical error, which is easier to handle, extending the use of coincidence methods to classical and non-classical multi-photon states.<br><p>QC 20180517</p>
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Montagna, Elisabetta. "Characterization of SiPMs for the photon detection system of the DUNE far detector." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21277/.
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The Deep Underground Neutrino Experiment (DUNE) is a next generation experiment with the purpose of studying neutrino oscillation. It will contribute in solving some still open questions as a neutrino mass ordering and a possible CP violation in the leptonic sector. The experiment will be implemented with a Near Detector (ND) and a Far Detector (FD), placed at a distance of ~1300 km. The FD complex will be composed of four detectors modules of Liquid Argon Time Projection Chambers. In order to detect the scintillation light emitted by neutrino interactions inside the detector, the FD will make use of a Photon Detection system formed by light collectors coupled to Silicon Photomultipliers (SiPMs).
This thesis is focused on the test activities carried out to verify the
compatibility of the photosensors to the experiment requirements necessary to ensure a uniform response of the system. A full characterization of the first SiPM sample is presented, studying their behaviour both at room and in cryogenic environment (77 K).
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Taylor, David Maurice. "Shallow Junction Single Photon Detection Technology for Quantum Information." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504229.
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The detection of single photons is now commonplace in labs across the world. This was initially due to the invention of photomultiplier tubes (PMTs) and multichannel plates (MCPs) but the explosion in adoption was undoubtedly due to the developments in Single Photon Avalanche Photodiodes (SPADs), and most notably in silicon. The cost, bulk, weight, and complexity all dropped, and thus significantly expanded the application space. Today SPADs are found in biophotonics, sensing, rangefinding, quantum key distribution (QKD), quantum computing, and more This thesis investigates a relatively new class of single photon detectors, commonly referred to as shallow junction SPADs, and their applicability to a range of applications. These offer a further step reduction in cost and additionally allow for the creation of individually addressable arrays as well as integrated circuitry along side the detection areas.
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Hees, Simon Söhnke. "Single photon detection using quantum dot resonant tunnelling diodes." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613151.
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Li, Li. "Detection of Proteins by Two-Photon Excitation of Native Fluorescence." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1548.pdf.
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Shibata, Masahiro. "Microwave Single-Photon Detection with Rydberg Atoms at Low Temperature." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/147804.
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Rath, Patrik [Verfasser], and M. [Akademischer Betreuer] Wegener. "Integrated optomechanics and single-photon detection in diamond photonic integrated circuits / Patrik Rath ; Betreuer: M. Wegener." Karlsruhe : KIT-Bibliothek, 2016. http://d-nb.info/1123146136/34.
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Intermite, Giuseppe. "Near infra-red single-photon detection using Ge-on-Si heterostructures." Thesis, Heriot-Watt University, 2015. http://hdl.handle.net/10399/3012.
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This Thesis investigates the design of Ge-on-Si single-photon avalanche diode (SPAD) detectors combining the many advantages of low-noise Si single-photon avalanche multiplication with the infrared sensing capability of germanium. The devices were simulated by using electric field modelling software to predict key aspects of the device behaviour in terms of the current-voltage characteristic and electric field. The devices were then characterised in terms of their single-photon performance. A 25 m diameter device showed a single-photon detection efficiency of ~ 4 % at a wavelength of 1310 nm and a temperature of 100 K when biased at 10 % above the breakdown voltage. In the same condition, a dark count rate of ~ 6 Mcs-1 was measured. This resulted in the lowest noise equivalent power of ~ 1 × 10-14 WHz-1/2 of Ge-on-Si SPADs reported in the scientific literature. At the longer wavelength of 1550 nm, the single-photon detection efficiency was reduced to ~ 0.1 % at 125 K and 6 % of relative excess bias. Although further investigation needs to be carried out, a potential major advantage of these devices compared to the InGaAs/InP SPADs could be that of reduced afterpulsing since a small increase (a factor of 2) in the normalised dark count rate was measured when the repetition rate was increased from 1 kHz to 1 MHz. Finally, the fill-factor enhancement of 32 × 32 Si CMOS SPAD arrays resulting from the integration of high efficiency diffractive optical microlens arrays was investigated. A full characterisation of SPAD arrays integrating microlens arrays in terms of improvement factor and spatial uniformity of detection is presented for the first time in the scientific literature in a large spectral range (500-900 nm) and different f-numbers (from f/2 to f/22) by using a double telecentric imaging system. The highest improvement factor of ~16 was measured for a SPAD array integrating microlens arrays, combined with a very high spatial efficiency uniformity of between 2–6%.
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Heath, Robert M. "Nano-optical studies of superconducting nanowire devices for single-photon detection." Thesis, University of Glasgow, 2015. http://theses.gla.ac.uk/6132/.
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Superconducting nanowire single photon detectors (SNSPDs) are a rapidly maturing detector technology that offer superior performance relative to competing infrared photon counting technologies. The original experimental work presented here explores three novel methods of improving and analysing detector characteristics, employing low-temperature piezoelectric motors at temperatures below 4 K in a closed-cycle cryostat. Utilizing the low-temperature piezoelectric nanopositioners in tandem with a miniature confocal microscope, this work specifically shows a spatially-separable parallel-wire SNSPD demonstrating one- and two-pixel photon discrimination, with the detector responding more quickly when triggering two pixels. The work demonstrates nanoantenna-coupled SNSPDs, which are simulated, designed, and tested using the same nano-optical setup. In these an increased local absorption into the nanowire is seen at the antennas' resonant wavelengths, enhancing the efficiency of the detector by up to 130 %. Finally, a modified optical setup using a distributed Bragg reflector fibre in place of the microscope to form a tunable cavity around two configurations of SNSPD is demonstrated, improving absorption of the incident light into the nanowire across the whole active area. For these, enhancement in the system detection efficiency of up to 40 % is seen.
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Beckett, Martin Gregory. "High resolution infrared imaging." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388828.
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Denissov, Alexandre. "Conditional homodyne detection and time asymmetric fluctuations of light /." view abstract or download file of text, 2004. http://wwwlib.umi.com/cr/uoregon/fullcit?p3153781.
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Thesis (Ph. D.)--University of Oregon, 2004.<br>Typescript. Includes vita and abstract. Includes bibliographical references (leaves 102 -106). Also available for download via the World Wide Web; free to University of Oregon users.
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Nogues, Gilles. "Détection sans destruction d'un seul photo : une expérience d'électrodynamique quantique en cavité." Paris 6, 1999. http://www.theses.fr/1999PA066373.
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Hallman, L. (Lauri). "Single photon detection based devices and techniques for pulsed time-of-flight applications." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526210445.
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Abstract In this thesis, a new type of laser diode transmitter using enhanced gain-switching suitable for use with a single photon avalanche diode (SPAD) detector was developed and tested in the pulsed time-of-flight laser range finding (lidar) application. Several laser diode versions were tested and the driving electronics were developed. The driving electronics improvements enabled a pulsing frequency of up to 1 MHz, while the maximum laser output power was about 5–40 W depending on the laser diode dimensions. The large output power is advantageous especially in conditions of strong photon noise emerging from ambient light outdoors. The length of the laser pulse matches the jitter of a typical SPAD detector providing several advantages. The new laser pulser structure enables a compact rangefinder for 50 m distance measurement outdoors in sunny conditions with sub-centimeter precision (σ-value) at a valid distance measurement rate of more than 10 kHz, for example. Single photon range finding techniques were also shown to enable a char bed level measurement of a recovery boiler containing highly attenuating and dispersing flue gas. In addition, gated single photon detector techniques were shown to provide a rejection of fluorescent photons in a Raman spectroscope leading to a greatly improved signal-to-noise ratio. Photonic effects were also studied in the case of a pulsed time-of-flight laser rangefinder utilizing a linear photodetector. It was shown that signal photon noise has an effect on the optimum detector configuration, and that pulse detection jitter can be minimized with an appropriate timing discriminator<br>Tiivistelmä Tässä työssä kehitettiin uudentyyppinen, tehostettua "gain-switchingiä" hyödyntävä laserdiodilähetin käytettäväksi yksittäisten fotonien avalanche-ilmaisimien (SPAD) kanssa, ja sitä testattiin pulssin lentoaikaan perustuvassa laseretäisyysmittaussovelluksessa. Useita laserdiodiversioita testattiin ja ohjauselektroniikkaa kehitettiin. Ohjauselektroniikan parannukset mahdollistivat jopa 1 MHz pulssitustaajuuden, kun taas laserin maksimiteho oli noin 5–40 W riippuen laserdiodin dimensioista. Suuri lähtöteho on edullinen varsinkin vahvoissa taustafotoniolosuhteissa ulkona. Laserpulssin pituus vastaa tyypillisen SPAD-ilmaisimen jitteriä tarjoten useita etuja. Uusi laserpulssitinrakenne mahdollistaa esimerkiksi kompaktin etäisyysmittarin 50 m mittausetäisyydelle ulkona aurinkoisessa olosuhteessa mm–cm -mittaustarkkuudella (σ-arvo) yli 10 kHz mittaustahdilla. Yksittäisten fotonien lentoaikamittaustekniikan osoitettiin myös mahdollistavan soodakattilan keon korkeuden mittauksen, jossa on voimakkaasti vaimentavaa ja dispersoivaa savukaasua. Lisäksi portitetun yksittäisten fotonien ilmaisutekniikan osoitettiin hylkäävän fluoresenssin synnyttämiä fotoneita Raman-spektroskoopissa, joka johtaa selvästi parempaan signaali-kohinasuhteeseen. Fotoni-ilmiöitä tutkittiin myös lineaarista valoilmaisinta hyödyntävän pulssin kulkuaikamittaukseen perustuvan lasertutkan tapauksessa. Osoitettiin, että signaalin fotonikohina vaikuttaa optimaaliseen ilmaisinkonfiguraatioon, ja että pulssin ilmaisujitteri voidaan minimoida sopivalla ajoitusdiskriminaattorilla
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Colon, Gomez Maria. "Squaraine dyes for two-photon fluorescence bioimaging applications." Honors in the Major Thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/834.
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Schwartz, Mario [Verfasser]. "Fully integrated GaAs-based quantum photonic circuits: resonant generation, splitting and detection of single-photon emission on-chip / Mario Schwartz." München : Verlag Dr. Hut, 2019. http://d-nb.info/1176251139/34.
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Hou, Ying. "Experimental and theoretical study of quantum dot resonant tunneling diodes for single photon detection." Licentiate thesis, KTH, School of Biotechnology (BIO), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9342.
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<p>Single photon detection has a broad application in the medical, telecommunication, as well as in infrared imaging fields. In this thesis I present my work in studying quantum dot (QD) resonant tunneling diodes (RTD) for single photon detection. The device was processed in the form of a free-standing small-area air bridge. A detailed series of experimental and theoretical characterizations have been performed to understand the electrical properties of the RTDs (without embedding any QDs) and QD-embedded RTDs (QDRTDs). It has been shown that external series and parallel resistances shift the resonant current peak to higher voltage, create the bistability effect observed in I-V characteristics, and reduce the peak-to-valley ratio. For the QDRTD device, three-dimensional wave packet carrier transport simulations show strong influence of the long-range Coulomb potential induced by the hole captured by the embedded InAs QDs, thus demonstrating the fundamental principle of single photon detection.</p><p> </p><p>Two works are planned for the continuation of the graduate study after Lic examination. The optical response of the QDRTD will be experimentally and theoretically characterized in order to optimize the quantum efficiency for single photon detection. I will then concentrate on processing a one-dimensional photodetector array aiming at practical biotechnology applications.</p>
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Seo, Yoseoph. "The Role of Generation Volume and Photon Recycling in "Transport Imaging" of Bulk Materials." Thesis, Monterey, California. Naval Postgraduate School, 2012.
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Approved for public release; distribution is unlimited.<br>The goal of this research was to use Monte Carlo simulations to further develop the model that describes transport imaging by including a more realistic description of the generation region created by the incident electrons. Monte Carlo simulation can be used to determine the energy distribution in bulk materials due to the interaction with incident electrons. In the simulation, the incident electrons undergo both elastic and inelastic scattering events. Through these events, the energy of the electrons is transferred to the target materials. This deposited energy can generate electron-hole pairs and then, via recombination, photons. In the experimental work, these photons are measured by a CCD camera connected to an optical microscope in a scanning electron microscope (SEM).
Monte Carlo simulations were performed for a range of target materials and compared to the luminescence distributions measured experimentally. The simulated energy distributions are always spatially narrower than the optical image from the SEM. We propose possible explanations that need to be evaluated: the relationship between deposited energy and final electron distributions in the target material and photon recycling, in which locally generated photons are reabsorbed to produce a wider luminescence distribution. Further experiments are proposed to identify the limiting factors determining the minimum luminescence distribution.
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Jude, Thomas. "Strangeness photoproduction off the proton at threshold energies." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4769.
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K+Λ photoproduction provides the best possibility for a model independent extraction of the photoproduction process and contributing resonances. To do this, it is vital that cross section measurements are well understood. This thesis presents pγ K+Λ differential cross sections from the reaction threshold, to an invariant centre of mass energy of 1.87 GeV. The data was taken at MAMI-C electron microtron facility in Mainz, Germany, during July 2007 and April 2009. The 1.5 GeV MAMI-C electron beam was used to produce an energy tagged bremsstrahlung photon beam with a maximum energy of 1.4 GeV and an intensity of 105γs-1MeV-1. The beam impinged upon a liquid hydrogen target, with reaction products detected in two segmented calorimeter arrays; the Crystal Ball detector and TAPS. This work pioneers a new method of K+ detection in segmented calorimeters, in which the K+ was identified from the signature of its weak decay inside the crystals of the calorimeter. This proved to be an excellent method of isolating K+ and accessing strangeness photoproduction channels, with good agreement between experimental and Geant4 simulated data. A novel method in seperating K+Λ and K+Σ0 final states was also developed by identifying the photon from the decay: Σ0 → Λγ. The intense photon beam at the MAMI-C facility enabled differential cross section data with greater invariant mass resolution than previous measurements. The new measurement near threshold imposes important constraints to effective field theories based on the approximate chiral symmetry of QCD. At higher centre of mass energies it also addresses the current problem of discrepant data sets and will form an important constraint on partial wave analysis for the nucleon excitation spectrum. As such, this work contributes to a major world wide programme aiming to extract the excitation spectrum of the nucleon and to understand the dynamics and interactions of its constituents. The greater statistics near threshold, and particularly at backwards K+ centre of mass angles will give new valuable constraints to contributions from meson and hyperonic resonances on the reaction mechanism. The high resolution of the photon beam (approximately 2 MeV) also allows the first search for narrow resonances coupling to KΛ final states. The differential cross sections give good agreement with Kaon-MAID partial wave solutions, apart from at backward angles close to threshold, where the data is lower. Near threshold, the data agrees with calculations from the chiral unitary framework of Borasoy et al, tending to be in better accordance with the model than previous data. No strong structure from potential narrow resonance states was observed over the centre of mass energy region of 1650-1700 MeV, where narrow structure has been observed in recent η photoproduction of the neutron.
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Nguyen, Krzysztof Quoc Khanh. "Characterisation of holographic projection as structured illumination in a Time-of-Flight based 3D imaging system." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/9953.
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This thesis describes work on a novel 3D imaging system that successfully implements optical feedback and noise rejection mechanisms. The system is a combination of three relatively new technologies, namely, holographic projection, Time of Flight (ToF) ranging and Single Photon Avalanche Diode (SPAD) sensors. Holographic projection is used to provide structured illumination with optical feedback instead of more commonly used uniform illumination in similar imaging systems. It is obtained using a Ferro-electric Liquid Crystal on Silicon Spatial Light Modulator (FLCoS SLM). The structured illumination with optical feedback can be operated at up to 60 Hz with the current device, and has been shown to provide an average gain of about 1.56 in useful light levels. Alternatively, a gain over a limited area of up to a factor of 9 is possible with the current system. Time of Flight ranging is a method of choice for the system when depth estimation is concerned. It works even at very low light levels and allows for sub-centimetre depth resolution. ToF method was implemented using 20 MHz laser diode with 50 ps pulse duration and 200 mW peak power, as well as a SPAD sensor. The SPAD sensor consisted of a 32 32 array of 50 μm pixels, each with 10 bit Time to Digital Converter (TDC) with 50 ps timing resolution. Sensor pixels feature 100 Hz mean Dark Count Rate (DCR). The use of SPAD sensors with an adaptive sensing algorithm presented in this work has been demonstrated to reduce effective noise levels as seen by the sensor by a factor of 16. As a result, a significant gain in depth resolution can be achieved. The quantification of this gain is explained in more detail within this work. Furthermore, the work describes in detail system design, methodology of experimental procedure as well as different algorithms essential to the correct operation of the system. Significant amount of time is dedicated to diffraction pattern generation for the use in holographic projection, as well as modelling of photon detection in SPAD sensors and associated peak detection necessary to extract depth information from histograms of timed of photons. Moreover, the thesis discusses potential applications for the system based on the results of system characterisation presented in this work. The current state of the system suggests best suitability for gaming and machine vision applications. Finally, the work offers potential solutions to the practical issues that remain unresolved in the current system, alternatives for components used and paths for potential future development of the system proposed.
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Rieke, Julian [Verfasser]. "Design of a compact photon detection system for the PANDA Disc DIRC prototype / Julian Rieke." Gießen : Universitätsbibliothek, 2017. http://d-nb.info/1136570055/34.
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Bergmann, Marcel [Verfasser]. "Optical quantum error correction and detection against photon loss for qubits and beyond / Marcel Bergmann." Mainz : Universitätsbibliothek Mainz, 2019. http://d-nb.info/1193141168/34.
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Herder, Charles H. (Charles Henry) III. "Study of ultranarrow superconducting NbN nanowires and nanowires under strong magnetic field for photon detection." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/51603.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2009.<br>Includes bibliographical references (leaves 32-34).<br>Photon detection is an integral part of experimental physics, high-speed communication, as well as many other high-tech disciplines. In the realm of communication, unmanned spacecraft are travelling extreme distances, and ground stations need more and more sensitive and selective detectors to maintain a reasonable data rate. In the realm of computing, some of the most promising new forms of quantum computing require consistent and efficient optical detection of single entangled photons. Due to projects like these, demands are increasing for ever more efficient detectors with higher count rates. The Superconducting Nanowire Single-Photon Detector (SNSPD) is one of the most promising new technologies in this field, being capable of counting photons as faster than 100MHz and with efficiencies around 50%. Currently, the leading competition is from the geiger-mode avalanche photodiode, which is capable of ~20 ~70% efficiency at a ~5MHz count rate depending on photon energy. In spite of this, the SNSPD is still a brand-new technology with many potential avenues unexplored. Therefore, it is still possible that we can achieve even better efficiencies and count rates to keep up with the requirements of burgeoning technologies. This photon detector consists of a meandering superconducting nanowire biased close to its critical current. In this regime, a single incident photon can cause a section of the detector to switch to normal conduction, producing a voltage pulse due to its now-finite resistance. An electron micrograph is given in figure 1. The intrinsic limitations of the detector (disregarding the optical coupling mechanism and the support electronics) are dominated by two primary points. First is the efficiency with which the detector converts an absorbed photon into a voltage pulse. This is controlled by the behavior of the excited electrons at the point of incidence. I will discuss this in greater detail in the next section. The second is the electrothermal time constant of the detector. This limits the relaxation time of the detector and therefore limits the maximum rate at which the detector can count photons. As we will see, detection efficiency increases as the number of Cooper pairs that need to be excited into the normal state to switch conduction modes decreases. One way to decrease the bandgap is to decrease the cross-section of the wire. This has already been shown to increase detection efficiency, but this cannot be done to arbitrarily narrow wires. Not only is there a limitation to fabrication, but there are also interesting quantum effects that occur at very narrow wire widths. Note that much of the research that has been done to understand these quantum effects has been undertaken on wires much wider than those we will be using. Simultaneously, most of the materials used previously have coherence lengths much longer than NbN. Therefore, even though our wires are narrower by a substantial factor, they are still wider than the coherence length of NbN. As such the validity of the one-dimensional approximation to be presented in in 2.2 is debatable for our wires. However, it should be apparent that regardless of behavior, thermal and quantum phase slips will be one of the limiting factors in producing ultra-narrow nanowire photon detectors. Until now, photon detectors have only used current biasing techniques. However, it is well known that both magnetic field and current have the effect of reducing the energy required to excite superconducting charge carriers. Therefore, it may be possible to detect photons using magnetic field close to H, instead of current close to Ic. It is important to note, however, that the readout of the detector in its current configuration depends on some bias current to produce a voltage pulse. Therefore, with the current detector architecture, one still needs a significant bias current. For my thesis, I have first investigated the theory of supercurrents in ultranarrow wires and confirmed the behavior of this theory with our materials and fabrication techniques in order to establish a lower bound for wire width where photon detection is still possible. In addition, I have constructed and executed an initial experiment to test how photon detectors behave under magnetic field bias conditions. I have measured how these different bias conditions affect the efficiency of the detector as well as the dark count rate.<br>by Charles H. Herder, III.<br>S.B.
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Gach, Jean-Luc. "Imageurs à amplification." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0317.
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La quête du détecteur parfait, sans bruit, capable de détecter des photons uniques dans le visible et l’infrarouge, et ultimement de déterminer leur énergie est le graal de la détection. Pour arriver à ce but, de nombreux scientifiques ont développé des dispositifs depuis plusieurs dizaines d’années, et les astronomes ont toujours été à la pointe en ce domaine. En ce sens les imageurs à amplification semblent être la voie la plus rapide et la plus prometteuse pour atteindre ce but ultime. Ainsi après un bref historique de l’état de l’art sont exposés les systèmes à comptage de photons (IPCS) développés au LAM, qui ont été utilisés sur les télescopes ESO 3m60, OHP 1m93 ou encore WHT 4m20. Sont ensuite abordés les dispositifs imageurs intégrés à amplification comme les EMCCD (Electron multiplying charge coupled devices) dans le visible, avec quelques exemples de leur utilisation en astronomie. C’est la technologie qui, appliquée aux senseurs de front d’onde, aura permis conjointement à d’autres développements l’avènement des optiques adaptatives extrêmes comme celle de l’instrument VLT-SPHERE ou encore de SUBARU-SCExAO. Pour finir les e-APD (electron initiated avalanche photodiode) dans l’infrarouge seront abordés. Les e-APD ont cette propriété très intéressante d’être des amplificateurs quasi parfaits, et ont une capacité à détecter l’énergie des photons, des propriétés qui seront développées et analysées. Nous finirons par les perspectives et les progrès que nous sommes en droit d’attendre dans les prochaines années<br>The quest for the perfect, noiseless detector, capable of detecting unique photons in the visible and infrared, and ultimately determining their energy is the grail of detection. To achieve this goal, many scientists have developed devices for several decades, and astronomers have always been at the forefront in this area. In this sense amplification imagers seem to be the fastest and most promising way to achieve this ultimate goal. Thus, after a brief history of the state of the art are exposed the photon counting systems (IPCS) developed at LAM, which were used on ESO telescopes 3m60, OHP 1m93 or WHT 4m20. Imaging integrated imaging devices such as Electron Multiplying Charge Coupled Devices (EMCCDs) are then discussed in the visible, with some examples of their use in astronomy. It is the technology that, applied to the wavefront sensors, has jointly enabled other developments the advent of extreme adaptive optics such as the VLT-SPHERE or SUBARU-SCExAO. To finish the e-APD (electron-induced avalanche photodiode) in the infrared will be discussed. E-APDs have this very interesting property of being almost perfect amplifiers, and have an ability to detect photon energy, properties that will be developed and analyzed. We will end up with the prospects and the progress that we are entitled to expect in the coming years
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Llewellyn, T. J. "Evaluation of a multi-element ismuth germanate converter for high resolution and efficiency annihilation photon detection." Thesis, University of Bristol, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377349.
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Lopez, Bruno. "Towards the detection of single photons in the mid-infrared." Thesis, KTH, Tillämpad fysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297517.
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In this project, the fabrication of single-photon detectors based on superconducting nanowires is presented, with great focus on extending their operation range to the mid infrared. In particular, Niobium Titanium Nitride (NbTiN) and Molybdenum Silicide (MoSi), superconducting materials with different properties, are presented, studied and used as fabrication platforms. Different approaches are followed, mainly adjusting the nanowire width and thickness to achieve near unity quantum efficiency at mid infrared wavelengths. With the vision of using these devices for atmospheric LIDAR and sensing experiments, saturation at 2050 nm is studied that corresponds to the absorption peak of CO2. For the best device made on NbTiN thin films, unity quantum efficiency is shown at 2050 nm with a time jitter of 116 ps at 1550 nm. Simulations using the transfer matrix method and the commercial software Lumerical are carried out, concluding that the devices made in NbTiN could have 23.1-26.7% system detection efficiency at 2050 nm on a Silicon SiO2/Si platform. Further improvements show that the detection efficiency could reach between 52-62% (for 0.33 and 0.5 fill factor, respectively calculated with FDTD simulations) by engineering optical cavities.<br>I detta projekt presenteras en fabrikations process för enstaka foton detektorer baserade på supraledande nanotrådar. Fokuset har legat på att utöka våglängds regionen där detektorernas kan detektera till mid-infrarött ljus. Två specifika supraledande material, Niobium Titan (NbTiN) och Molybdenum Silicide (MoSi), med olika egenskaper har studerats och använts som material. Dimensionerna på nanotrådarna, framför allt tjockleken och bredden, har optimerats för att uppnå nära enhetlig kvant-effektivitet vid mid-infraröda våglängder. Med visionen att detektorerna ska användas för atmosfäriska LiDAR mätningar har de studerats för satruering vid 2050 nm som motsvarar ett absorbtions maximum för CO2. Detektorerna tillverkade med NbTinN uppnådde 100% kvant effektivitet för 2050 nm ljus med ett tids jitter på 116 ps vid 1550 nm ljus. Simuleringar med överförings matrisen metoden och den kommersiella mjukvaran Lumerical visar att NbTiN detektorer placerade på en SiO2/Si platform kan ha en 23.1-26.7% effektivitet vid 2050 nm. Ytterligare simuleringas visar att effektiviteten kan nå upp till 52-62% (för 0.33 och 0.5 fyllnadsfaktor, respektive beräknad med FDTD) genom att inkludera optiska kaviteter.
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Merzi, Stefano. "Novel applications of FBK SiPMs in the detection of low energy ionizing radiation." Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/276309.
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Silicon photon multipliers, or SiPMs, are single photon detectors that have grown increasing interest in the last decade as an alternative to photomultiplier tubes in many field of physics, engineering and medicine.
Compared to PMTs, SiPMs are more compact, rugged and operate at much lower bias voltage, in the order of tens of volts. Moreover they are insensitive to magnetic field and can achieve a very high radiopurity
SiPM detectors work on the principle of a diode operated above the breakdown voltage, in Geiger mode. In this condition, the electric field in the depletion region is high enough that the electron-hole pairs, generated by a single photon absorption through photoelectric effect, create secondary charges by impact ionization in a potentially diverging avalanche effect that can be exploited to generate a macroscopical current at the output of the diode.
Thanks to this effect, the SiPM is capable of counting the number of impinging photons down to single photon level. Noise sources in the SiPM include dark counts and correlated noise. Dark counts are counts happening when an electron-hole pair is generated in the active volume of the device in absence of photon absorptions. These events are caused either by thermal generation, diffusion from the neutral region or by tunnel effect. Correlated noise events, or counts, on the other hand, are generated when a primary firing cell retriggers after a certain time or cause the triggering of another cell. All these noise sources introduce errors in the photon count by adding fake events to the output signal of the detector.Traditional SiPM application is 511 keV gamma-ray detection in PET machines, using scintillator LYSO crystals to convert a single gamma ray into a flash of visible photons. An application based on the same principle was studied in this thesis by coupling FBK RGB-HD SiPMs with CsI:Tl crystals in order to detect lower energy X and gamma-rays. This setup has proven to be effective in the detection of radiation with energy as low as 5.9 keV with a resolution of 38.3%, which is the minimum value of energy resolution measured with SiPMs coupled to scintillator crystals at such low energy. At the same time it was observed that large area detectors provided a dynamic range wide enough to simultaneously detect radiation ranging from 6.4 keV to 122 keV with minimal saturation. In another activity of this thesis it was developed a simulation software that reproduces the behaviour of a SiPM under different light conditions by taking into account the detector efficiency, the dead time and the recharge behaviour of its cells and theoretical modelizations of the noise parameters that affect the measurement. From a given light profile the simulation generates a waveform that reproduces the one measured during the operation of real SiPMs. This waveform was then analysed using FBK software developed for SiPM characterization and the results showed an excellent agreement between the simulated detector and a reference SiPM. This software will become a useful tool for the design of SiPMs for future experiments because it will allow to tune the properties of the detectors to specific applications and it will reduce the need of layout and process split to find the optimal configuration of the detector parameters.Among all FBK technologies, this work was focused on the position-sensitive LG-SiPM. Unlike standard SiPMs, which have a single output, the LG-SiPM employs a more complex structure that splits the current signal into four output channels with ratios depending on the position of the impinging light on its surface. Center of mass calculations are used to reconstruct the position of the firing cell with precision down to some tens of microns while maintaining the fast time response of SiPMs. An application of the LG-SiPM was studied in the framework of the ARIADNE experiment in collaboration with the university of Liverpool. In this work the LG-SiPM was used to detect scintillation light coming from ionization tracks generated by alpha particles inside a CF4 TPC chamber. The ionized electrons where drifted through the action of a high electric field in the TPC towards a THGEM where they created light with timing depending on the distance of each track segment from the scintillator. The LG detector was able to reconstruct the 3D track particle inside the chamber with an error below 8 mm RMS inside the 40 l chamber and, at the same time, to reconstruct the energy released by the particle as function of time and calculate the total energy of the interacting particle and its linear energy transfer. These results open a novel approach for the TPC position reconstruction that combines the low number of readout channels needed for the LG detector to its time-continuous response which allows to reconstruct the tree-dimensional track of a particle inside the chamber.During the experiment it emerged the presence of an artifact that drifted all the reconstructed tracks towards the centre of the detection area, at the end of the signal. This effect was studied by creating a second simulation software that recreates the electrical behaviour of the LG-SiPM equivalent circuit when one or more cells trigger. It was simulated the output of the circuit with different light conditions and different values of the circuit elements and it was observed that the presence of the artifact was related to low intensity currents flowing through the net of the LG-SiPM metal tracks and quenching resistors. Several simulations were run in order to identify the optimal configuration of parameters for the reduction of this unwanted effect and to implement improvements in future LG-SiPM productions.Another application of the LG-SiPM in the field of radiation detection is the position reconstruction of the scintillation light emitted by gamma-rays in a monolithic crystal. Using a thin CsI:Tl crystal and lowering the detector temperature it was possible to distinguish different positions of interaction on the surface of the detector with an error below 1 mm FWHM. This technology can be effective for the creation of monolithic, position sensitive X and gamma-ray detector with good energy resolution for low energy spectroscopy or medical imaging devices.
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Burns, Kimberly Ann. "Coupled multi-group neutron photon transport for the simulation of high-resolution gamma-ray spectroscopy applications." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29737.
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Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2010.<br>Committee Chair: Hertel, Nolan; Committee Member: Kulp, William David; Committee Member: Lee, Eva; Committee Member: Pagh, Richard; Committee Member: Petrovic, Bojan; Committee Member: Rahnema, Farzad; Committee Member: Smith, Eric; Committee Member: Wang, Chris. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Mancardi, Xavier. "Détecteur liquide multipixellisé, pour l’imagerie médicale et préclinique." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS236/document.
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Le projet CaLIPSO (Calorimètre Liquide Ionisation Position Scintillation Organométallique) a pour ambition de mettre au point un détecteur de γ 511 keV très efficace et très rapide pour la tomographie par émission de positons. Pour cela nous utilisons comme milieu de détection un nouveau liquide, le TMBi (TriMéthylBismuth). Dans le TMBi, l’interaction de photons γ produit des photons optiques et des paires électrons-ions. Le but de cette thèse est de mesurer les paramètres d’ionisation du TMBi et de construire, un détecteur de charge instrumentant efficacement ce liquide, et son électronique associée. Afin de pouvoir détecter les électrons libres créés par l’ionisation du liquide, celui-ci doit être ultrapur, c’est-à-dire débarrassé de tout composé électronégatif qui pourraient capturer les électrons et diminuer le signal. Ceci a été travaillé à l’aide de tamis moléculaires. Les signaux à détecter sont très faibles (fA, fC). Ainsi, l’environnement de l’expérience et le détecteur ont été développés pour des mesures très bas bruit (niveaux de bruit mesurés inférieurs à 10 fA et 200 électrons). Nous avons travaillé à mesurer le rendement d’ionisation (ou Gfi) qui quantifie le rendement de production de charge dans le liquide, la mobilité des électrons dans le TMBi et la résolution en énergie du détecteur. Ce sont les principaux paramètres permettant de valider l’utilisation de TMBi pour l’imagerie TEP. Les futurs développements comprennent la mise en œuvre d’un détecteur densément pixellisé et l’optimisation de la résolution en énergie<br>The CALIPSO project (Calorimètre Liquide Ionisation Position Scintillation Organométallique) aims to develop a very efficient and very fast 511 keV γ detector for positron emission tomography. For this we use an organometallic liquid for the detection medium, the TMBi (TriMéthylBismuth). In TMBi, the interaction of a γ photon produces optical photons and electron-ion pairs.The aim of this thesis is to measure the ionization parameters of the liquid TMBi and build an efficient charge detector and its associated electronics.In order to detect the free electrons created by the ionization in the liquid, this liquid must be highly pure (which means free of any electronegative compound which could capture electrons and reduce the signal). This has been worked on using molecular sieves.The signals to be detected are very weak (fA, fC). Thus, the test setup and detector were developed for very low noise measurements (measured noise levels below 10 fA and 200 electrons).We measured the ionization yield (or Gfi) which quantifies the charge production yield in the liquid, the electrons mobility in the TMBi and the energy resolution of the detector. These are the main parameters to validate the use of TMBi for PET imaging.Future developments include the implementation of a pixelated detector and optimization of the detector energy resolution
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Bastidon, Noemie [Verfasser], and Dieter [Akademischer Betreuer] Horns. "The cryogenic photon detection system for the ALPS II experiment: characterization, optimization and background rejection / Noemie Bastidon ; Betreuer: Dieter Horns." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2017. http://d-nb.info/1124591303/34.
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Albotǎ, Marius A. 1974. "Single-photon detection of 1.55 [mu]m entangled light and frequency upconversion in periodically poled lithium niobate for quantum communication." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87203.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.<br>In title on t.p., "[mu]" appears as the lower-case Greek letter.<br>Includes bibliographical references (p. 69-72).<br>by Marius A. Albotǎ.<br>S.M.
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Hiskett, Philip Anthony. "Investigation into the photon counting performance of InGaAs/InP separate absorption, grading and multiplication avalanche photodiodes at a wavelength of 1.55#mu#m." Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/557.
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Makarov, Vadim. "Quantum cryptography and quantum cryptanalysis." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Information Technology, Mathematics and Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1473.
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<p>This doctoral thesis summarizes research in quantum cryptography done at the Department of Electronics and Telecommunications at the Norwegian University of Science and Technology (NTNU) from 1998 through 2007.</p><p>The opening parts contain a brief introduction into quantum cryptography as well as an overview of all existing single photon detection techniques for visible and near infrared light. Then, our implementation of a fiber optic quantum key distribution (QKD) system is described. We employ a one-way phase coding scheme with a 1310 nm attenuated laser source and a polarization-maintaining Mach-Zehnder interferometer. A feature of our scheme is that it tracks phase drift in the interferometer at the single photon level instead of employing hardware phase control measures. An optimal phase tracking algorithm has been developed, implemented and tested. Phase tracking accuracy of +-10 degrees is achieved when approximately 200 photon counts are collected in each cycle of adjustment. Another feature of our QKD system is that it uses a single photon detector based on a germanium avalanche photodiode gated at 20 MHz. To make possible this relatively high gating rate, we have developed, implemented and tested an afterpulse blocking technique, when a number of gating pulses is blocked after each registered avalanche. This technique allows to increase the key generation rate nearly proportionally to the increase of the gating rate. QKD has been demonstrated in the laboratory setting with only a very limited success: by the time of the thesis completion we had malfunctioning components in the setup, and the quantum bit error rate remained unstable with its lowest registered value of about 4%.</p><p>More than half of the thesis is devoted to various security aspects of QKD. We have studied several attacks that exploit component imperfections and loopholes in optical schemes. In a large pulse attack, settings of modulators inside Alice's and Bob's setups are read out by external interrogating light pulses, without interacting with quantum states and without raising security alarms. An external measurement of phase shift at Alice's phase modulator in our setup has been demonstrated experimentally. In a faked states attack, Eve intercepts Alice's qubits and then utilizes various optical imperfections in Bob's scheme to construct and resend light pulses in such a way that Bob does not distinguish his detection results from normal, whereas they give Bob the basis and bit value chosen at Eve's discretion. Construction of such faked states using several different imperfections is discussed. Also, we sketch a practical workflow of breaking into a running quantum cryptolink for the two abovementioned classes of attacks. A special attention is paid to a common imperfection when sensitivity of Bob's two detectors relative to one another can be controlled by Eve via an external parameter, for example via the timing of the incoming pulse. This imperfection is illustrated by measurements on two different single photon detectors. Quantitative results for a faked states attack on the Bennett-Brassard 1984 (BB84) and the Scarani-Acin-Ribordy-Gisin 2004 (SARG04) protocols using this imperfection are obtained. It is shown how faked states can in principle be constructed for quantum cryptosystems that use a phase-time encoding, the differential phase shift keying (DPSK) and the Ekert protocols. Furthermore we have attempted to integrate this imperfection of detectors into the general security proof for the BB84 protocol. For all attacks, their applicability to and implications for various known QKD schemes are considered, and countermeasures against the attacks are proposed.</p><p>The thesis incorporates published papers [J. Mod. Opt. 48, 2023 (2001)], [Appl. Opt. 43, 4385 (2004)], [J. Mod. Opt. 52, 691 (2005)], [Phys. Rev. A 74, 022313 (2006)], and [quant-ph/0702262].</p>
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Jung, Aera. "JEM-EUSO prototypes for the detection of ultra-high-energy cosmic rays (UHECRs) : from the electronics of the photo-detection module (PDM) to the operation and data analysis of two pathnders." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC108/document.
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L’expérience JEM-EUSO (traduction de Observatoire spatial de l’univers extrême à bord du module de l'expérience japonaise) est conçu pour observer les UHECR en détectant la lumière fluorescente UV émise par la gerbe qui se développe lorsque les UHECR interagissent avec l'atmosphère terrestre. Les gerbes atmosphériques sont constituées de dizaines de milliards de particules secondaires ou plus traversant l'atmosphère quasiment à la vitesse de la lumière, excitant les molécules d'azote qui émettent ensuite de la lumière dans la gamme UV. Alors que cette « technique de fluorescence » est habituellement utilisée au sol, en opérant ainsi à partir de l'espace, JEM-EUSO, pour la première fois, fournira des statistiques élevées sur ces événements. Avec un large champ de vue de ± 30 °, JEM-EUSO pourra observer depuis l’espace un volume d'atmosphère beaucoup plus grand que ce qui est possible du sol, en collectant un nombre sans précédent d'événements UHECR aux plus hautes énergies.Pour les quatre prototypes d’expériences construites par la collaboration, nous avons développé un ensemble commun d'électronique, en particulier le système central d'acquisition de données capable de fonctionner au sol, sur des ballons à haute altitude et dans l'espace.Ces expériences utilisent toutes un détecteur composé d'un module de détection de photo (PDM) identique aux 137 qui seront présents sur la surface focale JEM-EUSO. La lumière UV générée par les gerbes atmosphériques à haute énergie passe le filtre UV et frappe les tubes à photomultiplicateurs multi-anodes (MAPMT). Les photons UV sont alors transformés en électrons, qui sont multipliés par les MAPMT et le courant qu’ils créent est amplifié par des cartes ASIC de circuit intégré (EC-ASIC), qui effectuent également le comptage des photons et l'estimation de charge. Une carte FPGA nommé PDM board s'interface avec ces cartes ASIC, fournissant des paramètres d'alimentation et de configuration à ces cartes ASIC, collecte alors les données et exécute le déclenchement d’acquisition de niveau 1.Dans le cadre de ces travaux, je me suis occupée de la conception, du développement, de l'intégration et du test la carte FPGA PDM board pour les missions EUSO-TA et EUSO-Balloon ainsi que des tests d'algorithme de déclenchement autonomes d’acquisitions et j'ai également analysé les données de vol d’EUSO-Balloon et de la campagne sol EUSO-TA d’octobre 2015.Dans cette thèse, je donnerai un bref aperçu des rayons cosmiques à haute énergie, y compris de leur technique de détection et des principales expériences pour les détecter (chapitre 1), je décrirai JEM-EUSO et ses pathfinders (chapitre 2), je présenterai les détails de la conception et de la fabrication du PDM (chapitre 3) et de la carte FPGA PDM board (chapitre 4), ainsi que des tests d'intégration d’EUSO-TA et d’EUSO-Balloon (chapitre 5). Je ferai un rapport sur la campagne EUSO-Balloon de 2014 (chapitre 6) et sur ses résultats (chapitre 7), y compris une analyse spécifique développée pour rechercher des variations globales de l'émissivité UV au sol et j’appliquerai une analyse similaire aux données collectées sur le site de Telescope Array (Chapitre 8). Enfin, je présenterai la mise en œuvre et le test du déclencheur de premier niveau (L1) dans la carte de contrôle FPGA (chapitre 9). Un bref résumé de la thèse sera donné au chapitre 10<br>The JEM-EUSO (Extreme Universe Space Observatory on-board the Japanese Experiment Module) international space mission is designed to observe UHECRs by detecting the UV fluorescence light emitted by the so-called Extensive Air Shower (EAS) which develop when UHECRs interact with the Earth’s atmosphere. The showers consist of tens of billions or more secondary particles crossing the atmosphere at nearly the speed of light, which excite nitrogen molecules which then emit light in the UV range. While this so-called “fluorescence technique'” is routinely used from the ground, by operating from space, JEM-EUSO will, for the first time, provide high-statistics on these events. Operating from space, with a large Field-of-View of ±30 °, allows JEM-EUSO to observe a much larger volume of atmosphere, than possible from the ground, collecting an unprecedented number of UHECR events at the highest energies.For the four pathfinder experiments built within the collaboration, we have been developing a common set of electronics, in particular the central data acquisition system, capable of operating from the ground, high altitude balloons, and space.These pathfinder experiments all use a detector consisting of one Photo-detection Modules (PDMs) identical to the 137 that will be present on the JEM-EUSO focal surface. UV light generated by high-energy particle air showers passes the UV filter and impacts the Multi-anode Photomultiplier Tubes (MAPMT). Here UV photons are converted into electrons, which are multiplied by the MAPMTs and fed into Elementary Cell Application-Specific Integrated Circuit (EC-ASIC) boards, which perform the photon counting and charge estimation. The PDM control board interfaces with these ASIC boards, providing power and configuration parameters, collecting data and performing the level 1 trigger. I was in charge of designing, developing, integrating, and testing the PDM control board for the EUSO-TA and EUSO-Balloon missions as well as the autonomous trigger algorithm testing and I also performed some analysis of the EUSO-Balloon flight data and data from the EUSO-TA October 2015 run.In this thesis, I will give a short overview of high-energy cosmic rays, including their detection technique and the leading experiments (Chapter 1), describe JEM-EUSO and its pathfinders including a description of each instrument (Chapter 2), present the details of the design and the fabrication of the PDM (Chapter 3) and PDM control board (Chapter 4), as well as the EUSO-TA and EUSO-Balloon integration tests (Chapter 5). I will report on the EUSO-Balloon campaign (Chapter 6) and results (Chapter 7), including a specific analysis developed to search for global variations of the ground UV emissivity, and apply a similar analysis to data collected at the site of Telescope Array (Chapter 8). Finally, I will present the implementation and testing of the first-level trigger (L1) within the FPGA of the PDM control board (Chapter 9). A short summary of the thesis will be given in Chapter 10
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Baudoin, Romain. "Analyse du bruit lors de la génération de somme de fréquences dans les cristaux de niobate de lithium périodiquement polarisés (PPLN) et applications en régime de comptage de photons." Thesis, Limoges, 2014. http://www.theses.fr/2014LIMO0068/document.
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Le processus de somme de fréquences optiques est utilisé dans certaines applications pour convertir des signaux de longueurs d’onde infrarouges vers le domaine de longueurs d’onde visibles. Cela permet de bénéficier de technologies plus performantes notamment en terme de détection et de propagation. Les travaux menés dans cette thèse s’intéressent à l’étude de phénomènes optiques parasites générés par ce processus non linéaire dans des cristaux de niobate de lithium périodiquement polarisés (PPLN) pour des applications de conversion de fréquences en régime de comptage de photons. La première partie de ce manuscrit montre l’intérêt du processus de somme de fréquences optiques dans le contexte technologique de la détection infrarouge en régime de comptage de photons, via le concept de détection hybride. Les éléments théoriques et l’état de l’art associés à la détection hybride seront également présentés dans cette première partie. La deuxième partie traite d’une étude comparative entre différents cristaux de PPLN pour la détection hybride à 1550 nm. Pour cela, une analyse expérimentale détaillée des processus parasites est effectuée. Les résultats de cette étude sont utilisés pour des applications en astronomie et en microscopie. Enfin, la troisième partie traite d’une application de la somme de fréquences en interférométrie stellaire. Les résultats de caractérisation des cristaux de PPLN sont mis à contribution dans l’optimisation d’un instrument pour l’astronomie appelé interféromètre à somme de fréquences. Les résultats d’observation sur le site astronomique du Mont Wilson ainsi que les perspectives de cette instrument y sont présentés<br>The sum frequency generation process is used in differents applications to convert signals from infrared wavelengths to the field of visible wavelength. This allows to benefit of more efficient technologies in terms of detection and propagation. This thesis describes the study of noise phenomena generated by this process in crystals of periodically poled lithium niobate (PPLN) for frequency up-conversion applications in photon counting regime. The first part of the manuscript shows the advantage of sum frequency generation process in the technological environment of the infrared detection on single photon counting regime, using the concept of hybrid detection. The theoretical elements and the state of the art associated with hybrid detection will also be presented in this first part. The second part deals with a comparative study between different PPLN for hybrid detection at 1550 nm. A detailed experimental analysis of the noise process is performed. The results of this study are used for applications in astronomy and microscopy. The third part deals with an application of the sum frequency in stellar interferometry. The results of PPLN’s characterization are involved in optimizing an instrument for astronomy called sum frequency interferometer. The results of observation on the astronomical site of Mount Wilson and the prospects of this instrument are presented
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Fedrici, Bruno. "Solutions évolutives pour les réseaux de communication quantique." Thesis, Université Côte d'Azur (ComUE), 2017. http://www.theses.fr/2017AZUR4117/document.
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Le déploiement de réseaux de communication quantique représente un défi auquel cette thèse apporte des solutions originales. Deux dispositifs très performants sont construits uniquement autour de composants standards de l'optique intégrée et des télécommunications optiques. Le premier correspond à un schéma de synchronisation tout optique sur longue distance à très haute cadence et de précision inégalée pour la communication sécurisée par cryptographie quantique. Le montage expérimental repose sur une configuration de relais quantique mettant en œuvre deux sources indépendantes de paires de photons intriqués dont il faut synchroniser les temps d'émissions. L’idée principale s’appuie sur l’utilisation d’un unique laser télécom picoseconde cadencé à 2.5 GHz afin de générer l’horloge et de pouvoir la distribuer efficacement aux deux sources. Nous démontrons la synchronisation de notre lien relais pour une distance effective séparant les sources de plus de 100 km. Le second dispositif correspond quant à lui à la réalisation d'une expérience de compression à une longueur d'onde des télécommunications réalisée, pour la première fois, de manière entièrement guidée. La lumière comprimée étant une ressource fondamentale dans bon nombre de protocoles d'information quantique, la réalisation de systèmes expérimentaux facilement reconfigurables et compatibles avec les réseaux télécoms fibrés existants représente une étape cruciale en vue du déploiement de dispositifs de communication quantique en régime de variables continues. Enfin, un traitement quantique des effets de gigue temporelle dans les détecteurs de photons 0N/0FF est proposé. Malgré l'importance des systèmes de détection dans les technologies quantiques photoniques émergentes, aucune modélisation quantique de leurs effets de gigue temporelle n'avait été, à notre connaissance, développé jusqu'à présent<br>This thesis presents solutions to the challenges of developing quantum communication networks. Two powerful experimental devices have been set up relying only on standard telecom and integrated optical components. The first device corresponds to an all-optical synchronization scheme allowing, with an unprecedented accuracy, quantum key distribution at a high rate over long distances. The experimental scheme relies on two independent entangled photon pair sources that have to be synchronized in their emission time. Our approach is based on using a 2.5 GHz picosecond telecom laser as a master clock to efficiently synchronize the different sources. We demonstrate the synchronization for an effective distance of 100 km between sources. With our second device, we perform a squeezing experiment at telecom wavelengths and this for the first time in a fully guided-wave approach. Squeezed light being a fundamental resource for several quantum information protocols, developing plug-and-play experimental devices that are compatible with already existing telecom fiber networks is of first interest in the perspective of future quantum networks. Finally, we propose a quantum description of timing jitter effects in 0N/0FF detectors. Despite the importance of detection systems in emerging photonic quantum technologies, no quantum description of their timing jitter effects has been proposed so far
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Darré, Pascaline. "L'interféromètre à somme de fréquences ALOHA en bande H : Des tests en laboratoire jusqu'aux premières franges sur le ciel." Thesis, Limoges, 2016. http://www.theses.fr/2016LIMO0067.
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La technique de l'interférométrie en astronomie permet d'observer des objets avec une haute résolution angulaire comparativement à l'utilisation d'un unique télescope. L'observation dans l'infrarouge moyen représente aujourd'hui un enjeu en interférométrie notamment pour l'étude des noyaux actifs de galaxie ou de la formation des planètes. Cependant ce domaine spectral est particulièrement contraignant puisqu'il est soumis à l'émission propre des éléments optiques de l'instrument mais également de l'atmosphère. Ce manuscrit développe les travaux effectués sur un nouvel instrument utilisant un processus de conversion de fréquence pour transposer le rayonnement infrarouge vers un domaine spectral permettant de s'affranchir de l'émission propres des optiques. Un prototype fonctionnant dans le proche infrarouge à 1,55 µm et convertissant, via une processus de somme de fréquences, le rayonnement dans le domaine visible autour de 630 nm grâce à une pompe intense à 1064 nm, a été mis en place pour démontrer, en laboratoire, le principe de cette solution innovante notamment dans le cadre de l'analyse de la cohérence spatiale d'un corps noir. L'objectif est maintenant de démontrer la capacité de l'instrument à détecter un objet réel. J'introduis dans cette thèse les notions théoriques essentielles à la compréhension des travaux présentés pour ensuite détailler le fonctionnement de l'instrument et les éléments d'amélioration apportés, notamment en terme de transmission, au cours de ma thèse. Les études préliminaires en laboratoire du comportement de l'instrument ont permis d'aboutir aux premières franges sur le ciel en utilisant la plus petite base (34 m) du réseau interférométrique CHARA et de rechercher la magnitude limite de l'instrument. L'utilisation du processus de conversion de fréquence a pour conséquence de filtrer le spectre converti. Ainsi dans la configuration actuelle de l'interféromètre, seul 0,6 nm du spectre infrarouge en entrée du cristal est converti à travers le processus de SFG. Afin d'augmenter la sensibilité, une solution est de créer plusieurs processus de SFG simultanément dans chaque étage de conversion afin d'échantillonner le spectre infrarouge converti. Cette solution requiert d'utiliser plusieurs sources de pompe indépendantes qui vont créer des systèmes de franges incohérents. Je présente l'analyse de la cohérence temporelle d'une source infrarouge large bande convertie via l'utilisation de deux sources de pompe et un moyen de synchroniser les différents systèmes de franges afin de maximiser le contraste<br>Interferometry is an instrumental technique suitable to perform astronomical observations at high angular resolution. Currently, the mid-infrared spectral domain is a real issue for the astronomical interferometry to characterize astronomical objects such as proto-planetary discs or active galactic nuclei. However, this spectral domain is subject to a large thermal background emission from the instrument and from the sky. This manuscript describes an innovative instrument using a nonlinear process of sum frequency generation to convert the mid-infrared radiation to a shorter wavelength domain where the thermal emission from the instrument is negligible. A prototype operating in the near-infrared at 1.55 µm and converting the radiation in the visible domain at 630 nm thanks to a strong pump at 1064 nm has already demonstrated its ability to analyse spatial coherence of a blackbody source. The present goal is to demonstrate its ability to detect an object on the sky. In this manuscript I introduce theoritical concepts necessary for an understanding of the overall operation of the instrument. Then, I describe the main improvements provided in this thesis, in particular concerning the instrumental transmission. The preliminary studies of the instrument operation resulted in the first on-sky fringes on the CHARA array and enabled to determine its limiting magnitude. The upconversion process acts as a filter on the converted spectrum. In the current instrumental configuration, only 0.6 nm of the input infrared spectrum is converted through the SFG process. For the purpose of increasing the instrumental sensitivity, we propose to sample the infrared spectrum by using several independent pump laser lines thus creating different incoherent fringe patterns. I present the temporal coherence analysis of a broadband infrared source converted by a dual-line pump laser and a method to synchronize the different fringe patterns to insure a maximum value of the contrast
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Santos, Carlos Alexandre Fernandes dos. "Thick-microstructures for MPGDs: simulations and experimental studies." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13660.
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Mestrado em Física<br>Cherenkov Imaging counters require large photosensitive areas, capable of single photon detection, operating at stable high gains under radioactive backgrounds while standing high rates, providing a fast response and a good time resolution, and being insensitive to magnetic fields.
The development of photon detectors based in Micro Pattern Gaseous detectors (MPGDs), represent a new generation of gaseous photon detectors. In particular, gaseous detectors based on stacked Thick-Gaseous Electron Multipliers (THGEMs), or THGEM based structures, coupled to a CsI photoconverter coating, seem to fulfil the requirements imposed by Cherenkov imaging counters.
This work focus on the study of the THGEM-based detectors response as function of its geometrical parameters and applied voltages and electric fields, aiming a future upgrade of the Cherenkov Imaging counter RICH-1 of the COMPASS experiment at CERN SPS. Further studies to decrease the fraction of ions that reach the photocathode (Ion Back Flow – IBF) to minimize the ageing and maximize the photoelectron extraction are performed. Experimental studies are complemented with simulation results, also perfomed in this work.<br>Os detetores de RICH (do inglês Ring Imaging Cherenkov) requerem grandes áreas fotossensíveis, capazes de operar em regime de fotão único, de modo estável e com ganhos elevados, em ambientes radioativos, ao mesmo tempo que são submetidos a elevadas taxas de irradiação, proporcionando uma resposta rápida e boa resolução temporal, e sendo insensíveis a campos magnéticos.
O desenvolvimento de foto-detetores baseados em detetores gasosos micro-estruturados (Micro Pattern Gaseous Detectors – MPGDs) representa uma nova geração de foto-detetores gasosos. Em particular, detetores gasosos baseados em múltiplas camadas de THGEMs (THick Gaseous Electron Multipliers), ou de estruturas baseadas em THGEMs, acoplados com uma camada foto-conversora de CsI, parecem reunir os requisitos impostos para aplicação em detetores de RICH.
Este trabalho incide no estudo da resposta de detetores gasosos baseados em THGEMs, em função dos seus parâmetros geométricos, e dos potenciais e campos elétricos aplicados, com vista à futura atualização do detetor RICH-1 da experiência COMPASS, no acelerador SPS no CERN. São realizados estudos adicionais para reduzir o refluxo de iões para o fotocátodo para minimizar o seu envelhecimento, e maximizar a eficiência de extração de fotoeletrões. Os estudos experimentais são complementados com resultados de simulações, realizadas também no âmbito deste trabalho.
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Paul, Uchenna Prince. "Fluorescence Detectors for Proteins and Toxic Heavy Metals." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd416.pdf.
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Lehmann, Lucien. "Apport des structures ridge pour la détection et l’interférométrie à conversion de fréquence MIR en régime de comptage de photons." Thesis, Limoges, 2019. http://www.theses.fr/2019LIMO0069/document.
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La détection faible flux dans le moyen infrarouge (MIR) est fortement pénalisée par le rayonnement thermique de l’environnement. La principale solution à ce problème consiste à cryogéniser la plus grande partie possible de la chaîne de détection. Cette méthode atteint ses limites pour certaines applications,notamment l’imagerie haute résolution en astronomie par méthode interférométrique. Une solution alternative consiste à utiliser le processus non linéaire de somme de fréquences pour convertir ce rayonnement moyen infrarouge vers des domaines de longueur d’onde où les détecteurs ne sont plus limités par le rayonnement de l’environnement et fonctionnent efficacement en régime de comptage de photons. Les travaux effectués au cours ces trois années sont le prolongement direct de plus d’une décennie de recherche pour la détection et l’interférométrie par conversion de fréquence. Ils s’inscrivent dans la continuité des travaux de thèses de L. Szemendera et de P. Darré, ayant, pour l’un, posé les premières pierres de l’interférométrie par conversion de fréquence dans le MIR et, pour l’autre, démontré la possibilité d’utiliser cette technique sur le ciel à1550 nmen tirant parti de la technologie de guidage ridge. Cette thèse constitue donc la jonction fructueuse de ces travaux antérieurs, rendue possible par une collaboration avec l’institut Femto-ST. L’utilisation de leurs guides PPLN ridge nous a permis de nous placer au niveau de l’état de l’art pour la détection par conversion de fréquence dans le MIR (3,5 μm)avec des démonstrations expérimentales à la fois en laboratoire et sur le ciel (C2PU). Intégrée à un interféromètre à conversion de fréquence à ces mêmes longueurs d’onde, elle a également permis d’en améliorer significativement les performances et la répétabilité de cette technique, principalement dans le cas d’une source spectralement large bande. Parallèlement, notre collaboration avec le réseau de télescopes CHARA, nous a offert l’opportunité d’étudier les problématiques soulevées par une future mise en œuvre de l’instrument sur ce site<br>Low flux detection in the mid infrared (MIR) is strongly penalized by thermal radiation from the environment. The main solution to this problem is to cryogenize as much of the detection chain as possible.This method is reaching its limits for some applications, including high-resolution imaging in astronomy using interferometric methods. An alternative solution is to use the non-linear process of sum frequency generation to convert this mid infrared radiation to wave length domains where detectors are no longer limited by the radiation from environment and operate efficiently in photon counting regime.The work over these three years is part of more than a decade of research into up-conversion detection and interferometry. It is the expansion of the these works of L. Szemendera and P. Darré. The first one laid the fondation of the up-conversion interferometry in the MIR and the second one demonstrated the possibility of using this technique on the sky at 1550 nm by benefiting from the ridge waveguide technology.Thus, this thesis constitutes the fruitful junction of these earlier works, made possible by a collaboration with the Femto-ST Institute. The use of their PPLN ridge waveguides has enabled us to place ourselves at the state of the art for up-conversion detection in the MIR (3,5 μm) with experimental demonstrations both in the laboratory and on the sky (C2PU). Integrated into a up-conversion interferometer at these same wave lengths, it has also significantly improved the performance and repeatability of this technique,in particular in the case of a spectrally broadband source. At the same time, our collaboration with the CHARA telescope array gave us the opportunity to study the problems raised by a future implementation of the instrument on this site
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Donati, Gaia. "Hybrid quantum information processing with continuous and discrete variables of light fields." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:673338dc-1233-43c8-be93-11b748a428a9.
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Quantum correlations play a fundamental role in quantum information science. The variety of their manifestations has become increasingly apparent following the development of novel light sources, protocols and photodetectors. One broad classification identifies two instances of non-classical correlations: particle and mode entanglement. These categories mirror two coexisting descriptions of quantum systems in terms of discrete and continuous variables of the electromagnetic field. The past decades have generated a number of promising results based on schemes which encompass elements from both frameworks, rather than viewing the two descriptions as mutually exclusive. In this context, it is possible to conceive and realise experiments where either the quantum resource or the detection system is 'hybrid'. Optical weak-field homodyne detectors bring together phase sensitivity and photon counting; as such, they represent a detection scheme which works across continuous and discrete variables of the radiation field. In this thesis we present a two-mode weak-field homodyne detection layout with added photon-number resolution and apply it to the study of a split single-photon state and a squeezed vacuum state. As a first test of the capabilities of this system, we investigate the reconstruction of relevant features of a given quantum resource - such as its photon statistics - with our detection scheme. Further, we experimentally demonstrate the observation of an instance of non-classical optical coherence which combines the continuous- and discrete-variable descriptions explicitly. The ability to probe phenomena at the interface of wave and particle regimes opens the way to novel, improved schemes for quantum information processing. From a more fundamental perspective, such hybrid approaches may shed light on the very roots of quantum enhancement.
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Ben, Younes Ridha. "Contribution à l'amélioration qualitative et quantitative des images de médecine nucléaire en tomographie d'émission à simple photon." Besançon, 1989. http://www.theses.fr/1989BESA2008.
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Reconstruction tomographique de la distribution radioactive d'un traceur placé dans le milieu non atténuant puis atténuant. Différentes méthodes de reconstruction, performances et contrôle de la qualité du détecteur, dégradation des images. Méthode de détection automatique des contours
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Najafi, Faraz. "Superconducting nanowire single-photon detectors : new detector architectures and integration with photonic chips." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99836.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 153-161).<br>Superconducting nanowire single-photon detectors (SNSPDs) are a promising technology for long-distance optical communication and quantum information processing. Recent advances in single-photon generation, storage and detection technologies have spurred interest in integration of these components onto a single microchip, which would act as a low-power non-classical optical processor. In this thesis, I will present a method for the scalable integration of SNSPDs with photonic chips. I will show that, using a micron-scale flip-chip process, waveguide-coupled SNSPDs can be integrated onto a variety of material systems with high yield. This technology enabled the assembly of the first photonic chip with multiple adjacent SNSPDs with average system detection efficiencies beyond 10%. Using this prototype, we will show the first on-chip detection of non-classical light. I will further demonstrate optimizations to the detector design and fabrication processes. These optimizations increased the direct fabrication yield and improved the timing jitter to 24 ps for detectors with high internal efficiency. Furthermore, I will show a novel single-photon detector design that may have the potential to reach photodetection dead times below 1ns.<br>by Faraz Najafi.<br>Ph. D.
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Cajgfinger, Thomas. "Etudes théorique et expérimentale du suivi de particules uniques en conditions extrêmes : imagerie aux photons uniques." Phd thesis, Université Claude Bernard - Lyon I, 2012. http://tel.archives-ouvertes.fr/tel-00999629.
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Ce manuscrit présente mon travail de thèse portant sur le détecteur de photons niques electron-bpmbarded CMOS (ebCMOS) à haute cadence de lecture (500 images/seconde). La première partie compare trois détecteurs ultra-sensibles et leurs méthodes d'amélioration de la sensibilité au photon : le CMOS bas bruit sCMOS), l'électron-multiplying CCD (emCCD) à multiplication du signal apr pixel et l'ebCMOS à amplification par application d'un champ électrique. La méthode de mesure de l'impact intra-pixel des photons sur le détecteur ebCMOS est présentée. La seconde partie compare la précision de localisation de ces trois détecteurs dans des conditions extrêmes de très bas flux de phtons (<10 photons/image). La limite théoriques est d'abord calculée à l'aide de la limite inférieure de Cramér-Rao pour ces jeux de paramètres significatifs. Une comparaison expérimentale des trois détecteurs est ensuite décrite. Le montage permet la création d'un ou plusieurs points d'accès contrôlés en position, nombre de photons et bruit de fond. Les résultats obtenus permettent une comparaison de l'efficacité, de la pureté et de la précision de localisation des sources. La dernière partie décrit deux expériences réalisées avec la caméra ebCMOS. La première consiste au suivi des nano-cristaux libres (D>10 µm2/s) au centre Nanoptec avec l''équipe de Christophe Dujardin. La seconde s'intéresse à la nage de bactéries en surface à l'Institu Joliot curie avec l'équipe de Laurence Lemelle. L'algorithme de suivi de sources ponctuelles au photon unique avec l'implémentation d'un filtre de Kalman est aussi décrit.
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Benhammou, Younes. "Développement de SPADs (Single Photon Avalanche Diodes) à cavité de germanium sur silicium en intégration 3D avec une technologie silicium CMOS 40nm." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI123.
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Cette thèse porte sur une famille de photo-détecteurs appelés SPAD pour Single Photon Avalanche Diodes qui sont des jonctions PN polarisées en inverse au-delà de la tension de claquage. Les diodes SPADs sont reconnues pour présenter de très bonnes performances en détection de faibles flux lumineux avec une réponse extrême rapide. Afin d’améliorer l’efficacité de détection dans le proche infrarouge de diodes SPAD sur silicium, les objectifs de la thèse sont de concevoir, fabriquer et caractériser une nouvelle génération de photodiodes SPADs dans une technologie CMOS 40nm en intégrant une cavité de germanium. Les travaux menés comportent i) un volet conception en utilisant des outils de simulation TCAD pour proposer une architecture originale optimisée, ii) le développement du flot complet du procédé technologique avec la création de nouvelles briques telles que la gravure de la cavité et l’épitaxie de germanium dopé in-situ, 3) la caractérisation électro-optique des composants issus des premiers lots fabriqués. Les analyses et interprétations des résultats obtenus révèlent la difficulté technologique pour réaliser une hétérojonction silicium-germanium sans défauts et une couche germanium de qualité. Néanmoins, les mesures réalisées ont démontré la capacité de cette nouvelle famille de SPAD à cavité de germanium sur plateforme silicium pour détecter les flux jusqu’à 1300nm, démontrant un fort potentiel applicatif pour les applications d’aide à la navigation<br>This thesis deals with a family of photo-detectors called SPAD for Single Photon Avalanche Diodes which are a PN junctions reverse biased beyond the breakdown voltage. SPADs diodes are known to have very good performance in detecting low light fluxes with an extremely fast response. In order to improve the near infrared detection efficiency of SPAD diodes on silicon, the objectives of the thesis are to design, manufacture and characterize a new generation of SPAD photodiodes in 40nm CMOS technology by integrating a germanium cavity. The work carried out includes i) design and simulation using TCAD tools to propose an optimized original architecture, ii) development of the process flow in industrial imager technological with the creation of new bricks such as etch of the cavity and epitaxy of germanium in-situ doped 3) the electro-optical characterization of the manufactured devices. The results obtained reveal technological difficulty to produce a silicon-germanium heterojunction without defects. Nevertheless, the measurements carried out demonstrated the ability of this new family of germanium cavity SPADs on a silicon platform to detect wavelengths up to 1300nm, demonstrating a strong potential for time of light applications