Journal articles: 'Photon emission'

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Rivera, Nicholas, Gilles Rosolen, John D. Joannopoulos, Ido Kaminer, and Marin Soljačić. "Making two-photon processes dominate one-photon processes using mid-IR phonon polaritons." Proceedings of the National Academy of Sciences 114, no. 52 (December 12, 2017): 13607–12. http://dx.doi.org/10.1073/pnas.1713538114.

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Phonon polaritons are guided hybrid modes of photons and optical phonons that can propagate on the surface of a polar dielectric. In this work, we show that the precise combination of confinement and bandwidth offered by phonon polaritons allows for the ability to create highly efficient sources of polariton pairs in the mid-IR/terahertz frequency ranges. Specifically, these polar dielectrics can cause emitters to preferentially decay by the emission of pairs of phonon polaritons, instead of the previously dominant single-photon emission. We show that such two-photon emission processes can occur on nanosecond time scales and can be nearly 2 orders of magnitude faster than competing single-photon transitions, as opposed to being as much as 8–10 orders of magnitude slower in free space. These results are robust to the choice of polar dielectric, allowing potentially versatile implementation in a host of materials such as hexagonal boron nitride, silicon carbide, and others. Our results suggest a design strategy for quantum light sources in the mid-IR/terahertz: ones that prefer to emit a relatively broad spectrum of photon pairs, potentially allowing for new sources of both single and multiple photons.

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Mohammed Ahmed, Elaf, Hadi J. M. Al-Agealy, and Nada Farhan Kadhim. "Theoretical Calculation of Photon Emission from Quark-Antiquark Annihilation Using QCD Theory." Ibn AL-Haitham Journal For Pure and Applied Sciences 35, no. 4 (October 20, 2022): 37–44. http://dx.doi.org/10.30526/35.4.2879.

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In this work, we calculate and analyze the photon emission from quark and anti-quark interaction during annihilation process using simple model depending on phenomenology of quantum chromodynamic theory (QCD). The parameters, which include the running strength coupling, temperature of the system and the critical temperature, carry information regarding photon emission and have a significant impact on the photons yield. The emission of photon from strange interaction with anti-strange is large sensitive to decreases or increases there running strength coupling. The photons emission increases with decreases running strength coupling and vice versa. We introduce the influence of critical temperature on the photon emission rate in order to facilitate its further applied in photon emission spectrum. Photon emission was increased with large critical temperature MeV comparing with photons emission at critical temperature MeV. We analyze and discuss the sensitive of the emission of photon to photons energy . It increases with decreased photons energy and vice versa. However, the photons emission increases with increases thermal energy of system T = 170 MeV to 270 Mev. It is implied that strength coupling, critical temperature and photons energy can be as important as thermal energy of system for emission of photon.

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Mizuno, Y., and T. Mizuno. "Photon emission accompanying deformation and fracture of ice." Canadian Journal of Physics 81, no. 1-2 (January 1, 2003): 71–80. http://dx.doi.org/10.1139/p03-012.

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We observed photon emission during deformation and fracture of axially loaded polycrystalline ice. Emission of visible photons (300650 nm) was correlated with crack generation and fracture, based on time-resolved photon emission signals taken during load changes. Emission intensity, including the entire spectra ranging from 300 to 650 nm, was roughly correlated with increasing strain energy released by fracturing, while considerable scattering of the intensity data implied that emission intensity also depended on the characteristics of each individual crack. Correlation was taken between simultaneous emissions detected with two photomultiplier tubes with different ranges of spectral sensitivity. Brief, intense emissions were clearly associated with load drops, and these probably included wavelengths shorter than 320 nm, indicating that near ultraviolet light is also emitted. On the other hand, weak but continuous signals with wavelengths longer than 650 nm were emitted the entire time the ice was subjected to a load. Emission intensity and spectra may be attributed to microprocesses during fracturing. Experimental evidence for emission of visible photons indicates that the generated electric charges on crack surfaces and at crack tips have energy ranging from 2 to 6 eV. PACS No.: 46.50

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Dovlatova, Alla, and Dmitri Yerchuck. "Quantum Field Theory of Dynamics of Spectroscopic Transitions by Strong Dipole-Photon and Dipole-Phonon Coupling." ISRN Optics 2012 (December 12, 2012): 1–10. http://dx.doi.org/10.5402/2012/390749.

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Matrix-operator difference-differential equations for dynamics of spectroscopic transitions in 1D multiqubit exchange-coupled (para)magnetic and optical systems by strong dipole-photon and dipole-phonon coupling are derived within the framework of quantum field theory. It has been established that by strong dipole-photon and dipole-phonon coupling the formation of long-lived coherent system of the resonance phonons takes place, and relaxation processes acquire pure quantum character. It is determined by the appearance of coherent emission process of EM-field energy, for which the resonance phonon system is responsible. Emission process is accompanied by phonon Rabi quantum oscillation, which can be time-shared from photon quantum Rabi oscillations, accompanying coherent absorption process of EM-field energy. For the case of radio spectroscopy, it corresponds to the possibility of the simultaneous observation along with (para)magntic spin resonance, the acoustic spin resonance.

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Kontos, Antonios, and Rainer Weiss. "Photon emission spectrum of ion pumps." Review of Scientific Instruments 94, no. 3 (March 1, 2023): 034503. http://dx.doi.org/10.1063/5.0138917.

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As the sensitivity of gravitational-wave detectors increases, new sources of noise appear. A potential source of noise may arise from charge accumulating on the mirrors of the experiment, the origin of which can be related to UV photons from the surroundings. In order to test one hypothesis, we measured the photon emission spectrum from a type of ion pump that is used in the experiment, an Agilent VacIon Plus 2500 l/s. We found that there is significant emission of UV photons above 5 eV, capable of knocking electrons off mirrors or surrounding surfaces and charging them. Photon emission measurements were taken as a function of gas pressure, ion-pump voltage setting, and type of pumped gas. The overall emission and shape of the measured photon spectrum are consistent with bremsstrahlung as the mechanism for the production of the photons.

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McLaughlin, Joseph Biagio, Giacomo Gallina, Fabrice Retière, Austin De St. Croix, Pietro Giampa, Mahsa Mahtab, Peter Margetak, et al. "Characterisation of SiPM Photon Emission in the Dark." Sensors 21, no. 17 (September 4, 2021): 5947. http://dx.doi.org/10.3390/s21175947.

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In this paper, we report on the photon emission of Silicon Photomultipliers (SiPMs) from avalanche pulses generated in dark conditions, with the main objective of better understanding the associated systematics for next-generation, large area, SiPM-based physics experiments. A new apparatus for spectral and imaging analysis was developed at TRIUMF and used to measure the light emitted by the two SiPMs considered as photo-sensor candidates for the nEXO neutrinoless double-beta decay experiment: one Fondazione Bruno Kessler (FBK) VUV-HD Low Field (LF) Low After Pulse (Low AP) (VUV-HD3) SiPM and one Hamamatsu Photonics K.K. (HPK) VUV4 Multi-Pixel Photon Counter (MPPC). Spectral measurements of their light emissions were taken with varying over-voltage in the wavelength range of 450–1020 nm. For the FBK VUV-HD3, at an over-voltage of 12.1±1.0 V, we measured a secondary photon yield (number of photons (γ) emitted per charge carrier (e−)) of (4.04±0.02)×10−6γ/e−. The emission spectrum of the FBK VUV-HD3 contains an interference pattern consistent with thin-film interference. Additionally, emission microscopy images (EMMIs) of the FBK VUV-HD3 show a small number of highly localized regions with increased light intensity (hotspots) randomly distributed over the SiPM surface area. For the HPK VUV4 MPPC, at an over-voltage of 10.7±1.0 V, we measured a secondary photon yield of (8.71±0.04)×10−6γ/e−. In contrast to the FBK VUV-HD3, the emission spectra of the HPK VUV4 did not show an interference pattern—likely due to a thinner surface coating. The EMMIs of the HPK VUV4 also revealed a larger number of hotspots compared to the FBK VUV-HD3, especially in one of the corners of the device. The photon yield reported in this paper may be limited if compared with the one reported in previous studies due to the measurement wavelength range, which is only up to 1020 nm.

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AKSENOV, A. G., R. RUFFINI, I. A. SIUTSOU, and G. V. VERESHCHAGIN. "DYNAMICS AND EMISSION OF MILDLY RELATIVISTIC PLASMA." International Journal of Modern Physics: Conference Series 12 (January 2012): 1–9. http://dx.doi.org/10.1142/s2010194512006204.

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Initially optically thick (with τ = 3⋅107) spherically symmetric outflow consisting of electron-positron pairs and photons is considered. We do not assume thermal equilibrium, and include the two-body processes that occur in such plasma: Möller and Bhabha scattering of pairs, Compton scattering, two-photon pair annihilation, two-photon pair production, together with their radiative three-body variants: bremsstrahlung, double Compton scattering, and three-photon pair annihilation, with their inverse processes. We solve numerically the relativistic Boltzmann equations in spherically symmetric case for distribution functions of pairs and photons. Three epochs are considered in details: a) the thermalization, which brings initially nonequilibrium plasma to thermal equilibrium; b) the self-accelerated expansion, which we find in agreement with previous hydrodynamic studies and c) decoupling of photons from the expanding electron-positron plasma. Photon spectra are computed, and appear to be non thermal near the peak of the luminosity. In particular, the low energy part of the spectrum contain more power with respect to the black body one.

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Yang, Ming, Shun An Chen, Qian Ru Lin, and Tao Pang. "Temperature Sensing Assists the Understanding of Er³⁺ Concentration Dependent Anti-Stokes Luminescence in NaYF₄:Er³⁺/Yb³⁺ Nanophosphors." Materials Science Forum 1003 (July 2020): 241–46. http://dx.doi.org/10.4028/www.scientific.net/msf.1003.241.

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In this paper, upcovnerison luminescence in Er3+/Yb3+ co-doped NaYF4 nanophosphors was regulated by changing the Er3+ concentration. With increasing the Er3+ concentration, the green and red emissions increased first and then decreased, but the intensity ratio of red to green emission decreased monotonically. To clarify the role of Er3+ doping, the factors including crystal structure, morphology and size of particle, photon absorption, energy transfer, multi-phonon relaxation, population of emissive levels and emission probability of radiative transitions were considered and analyzed. More importantly, we proposed a simple method for discussing radiation transitions based on luminescence temperature sensing.

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Chef, Samuel, Chung Tah Chua, and Chee Lip Gan. "Machine Learning for Time-Resolved Emission: Image Resolution Enhancement." EDFA Technical Articles 23, no. 3 (August 1, 2021): 24–31. http://dx.doi.org/10.31399/asm.edfa.2021-3.p024.

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Abstract This article describes a novel method for improving image resolution achieved using time-resolved photon emission techniques. Instead of directly generating images from photon counting, all detected photons are displayed as a point cloud in 3D space and a new higher-resolution image is generated based on probability density functions associated with photon distributions. Unsupervised learning algorithms identify photon distribution patterns as well as fainter emission sources.

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Melrose, D. B. "Induced photon decay and photon-beam-induced Langmuir turbulence." Journal of Plasma Physics 51, no. 1 (February 1994): 13–27. http://dx.doi.org/10.1017/s0022377800017360.

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A pair of quasi-linear-like equations is derived to describe the effect of three-wave interactions between high-frequency photons and Langmuir waves in a differential approximation. Induced photon decay leads to terms analogous to those for spontaneous emission, but involving the square of the photon occupation number. The effect on the Langmuir waves is evaluated for axisymmetric photons. The effect on the photons is shown to be similar to but weaker than induced Compton scattering by thermal electrons. The absorption coefficient for the Langmuir waves is evaluated for an axisymmetric distribution of photons, and used to discuss a photon-beam-induced instability. Possible astrophysical applications to solar ‘spike’ bursts, the eclipse of a radio pulsar and the variable low-frequency emission from some active galactic nuclei are discussed briefly, and it is concluded that the process can account for the observed properties of the eclipse of PSR 1957 + 20.

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Hu, Kun, Matthew G. Baring, Alice K. Harding, and Zorawar Wadiasingh. "High-energy Photon Opacity in the Twisted Magnetospheres of Magnetars." Astrophysical Journal 940, no. 1 (November 1, 2022): 91. http://dx.doi.org/10.3847/1538-4357/ac9611.

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Abstract Magnetars are neutron stars characterized by strong surface magnetic fields generally exceeding the quantum critical value of 44.1 TG. High-energy photons propagating in their magnetospheres can be attenuated by QED processes like photon splitting and magnetic pair creation. In this paper, we compute the opacities due to photon splitting and pair creation by photons emitted anywhere in the magnetosphere of a magnetar. Axisymmetric, twisted dipole field configurations embedded in the Schwarzschild metric are treated. The paper computes the maximum energies for photon transparency that permit propagation to infinity in curved spacetime. Special emphasis is given to cases where photons are generated along magnetic field loops and/or in polar regions; these cases directly relate to resonant inverse Compton scattering models for the hard X-ray emission from magnetars and Comptonized soft gamma-ray emission from giant flares. We find that increases in magnetospheric twists raise or lower photon opacities, depending on both the emission locale and the competition between field-line straightening and field strength enhancement. Consequently, given the implicit spectral transparency of hard X-ray bursts and persistent “tail” emission of magnetars, photon splitting considerations constrain their emission region locales and the twist angle of the magnetosphere; these constraints can be probed by future soft gamma-ray telescopes such as COSI and AMEGO. The inclusion of twists generally increases the opaque volume of pair creation by photons above its threshold, except when photons are emitted in polar regions and approximately parallel to the field.

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Prasad, Ankush, Prabhakar Gouripeddi, Hanumanth Rao Naidu Devireddy, Alina Ovsii, Dattatreya Prabhu Rachakonda, Roeland Van Wijk, and Pavel Pospíšil. "Spectral Distribution of Ultra-Weak Photon Emission as a Response to Wounding in Plants: An In Vivo Study." Biology 9, no. 6 (June 26, 2020): 139. http://dx.doi.org/10.3390/biology9060139.

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It is well established that every living organism spontaneously emits photons referred to as ultra-weak photon emission (synonym biophotons or low-level chemiluminescence) which inherently embodies information about the wellbeing of the source. In recent years, efforts have been made to use this feature as a non-invasive diagnostic tool related to the detection of food quality, agriculture and biomedicine. The current study deals with stress resulting from wounding (mechanical injury) on Arabidopsis thaliana and how it modifies the spontaneous ultra-weak photon emission. The ultra-weak photon emission from control (non-wounded) and stressed (wounded) plants was monitored using different modes of ultra-weak photon emission measurement sensors like charge-coupled device (CCD) cameras and photomultiplier tubes (PMT) and the collected data were analyzed to determine the level of stress generated, photon emission patterns, and underlying biochemical process. It is generally considered that electronically excited species formed during the oxidative metabolic processes are responsible for the ultra-weak photon emission. In the current study, a high-performance cryogenic full-frame CCD camera was employed for two-dimensional in-vivo imaging of ultra-weak photon emission (up to several counts/s) and the spectral analysis was done by using spectral system connected to a PMT. The results show that Arabidopsis subjected to mechanical injury enhances the photon emission and also leads to changes in the spectral pattern of ultra-weak photon emission. Thus, ultra-weak photon emission can be used as a tool for oxidative stress imaging and can pave its way into numerous plant application research.

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Ahmed, Elaf Mohammed, Hadi J. M. Al-Agealy, and Nada Farhan Kadhim. "Study of Photons Emission Rate of Quark-Antiquark at Higher Energy." Al-Mustansiriyah Journal of Science 33, no. 4 (December 30, 2022): 146–52. http://dx.doi.org/10.23851/mjs.v33i4.1193.

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In this paper, the dynamic of quark and anti-quark interaction has been used to study the production of photons in the annihilation process based on the theory of chromodynamic. The rate of the photon is to be calculated for charm and anti-strange interaction c→γg system with critical temperature 113 and 130 MeV and photon energy GeV/c. Here the critical temperature, strength coupling and photons energy are assumed to be affected dramatically on the rate of photons emission of state interaction c, which can form gluon possible structures and photon emission state. The decreased photons emission yields with increased strength couple of quarks reaction due to increase critical temperature from 113 MeV to 130 MeV were predicted. We can be found less difference in photons rate for the two different critical temperatures and strength coupling.

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LESTONE, J. P. "BLACK-BODY PHOTON CLUSTERING BY SEMICLASSICAL MEANS." Modern Physics Letters A 23, no. 15 (May 20, 2008): 1067–77. http://dx.doi.org/10.1142/s0217732308027199.

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If stimulated emission could be turned off, then only uncorrelated photons would be emitted from black bodies and the photon counting statistics would be Poissonian. Through the process of stimulated emission, some fraction of the photons emitted from a black body are correlated and thus emitted in clusters. This photon clustering can be calculated by semiclassical means. The corresponding results are in agreement with quantum theory.

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DOLOCAN, ANDREI, VOICU OCTAVIAN DOLOCAN, and VOICU DOLOCAN. "SOME ASPECTS OF THE ELECTRON-BOSON INTERACTION AND OF THE ELECTRON-ELECTRON INTERACTION VIA BOSONS." Modern Physics Letters B 21, no. 01 (January 10, 2007): 25–36. http://dx.doi.org/10.1142/s0217984907012335.

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By using a Hamiltonian of interaction between fermions via bosons1 we derive some properties of the electro-phonon and electron-photon interaction and also of the electron-electron interaction. We have obtained that in a degenerate electron gas there is an attraction between two electrons via acoustical phonons. Also, in certain conditions, there may be an attraction between two electrons via longitudinal optical phonons. Although our expressions for the polaron energy in both cases of the acoustical and longitudinal optical phonons are different from that obtained in the standard theory, their magnitudes are the same with these and they are in good agreement with experimental data. The total emission rate of an electron against a phonon system at absolute zero is directly proportional to the electron momentum. Also, an attraction between two electrons may appear via photons.

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Kumano, H., H. Nakajima, S. Ekuni, Y. Idutsu, H. Sasakura, and I. Suemune. "Quantum-Dot-Based Photon Emission and Media Conversion for Quantum Information Applications." Advances in Mathematical Physics 2010 (2010): 1–13. http://dx.doi.org/10.1155/2010/391607.

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Single-photon as well as polarization-correlated photon pair emission from a single semiconductor quantum dots is demonstrated. Single photon generation and single photon-pair generation with little uncorrelated multiphoton emission and the feasibility of media conversion of the quantum states between photon polarization and electron spin are fundamental functions for quantum information applications. Mutual media conversion for the angular momentum between photon polarization and electron spin is also achieved with high fidelity via positively charged exciton state without external magnetic field. This is a clear indication that the coupling of photon polarizations and electron spins keeps secured during whole processes before photon emission. Possibility of a metal-embedded structure is demonstrated with the observation of drastic enhancement of excitation and/or collection efficiency of luminescence as well as clear antibunching of photons generated from a quantum dot.

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Kuroki, Yuichiro, Minoru Osada, Ariyuki Kato, Tomoichiro Okamoto, and Masasuke Takata. "Exciton-Phonon Interaction in CuAlS₂ Powders." Advanced Materials Research 11-12 (February 2006): 175–78. http://dx.doi.org/10.4028/www.scientific.net/amr.11-12.175.

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High-resolution photoluminescence (PL) measurement was carried out for copper aluminum disulfide (CuAlS2) powder at 12 K. Several sharp PL lines were observed in the range from 3.580 to 3.320 eV. The emission peaks at photon energies from 3.566 to 3.459 eV were attributed to free-exciton (FE) and bound-excitons (BE). The several weak emissions at below 3.476 eV were clarified to be phonon replicas (PR) by Raman scattering and in the viewpoint of exciton-phonon interaction. We observed the one, two and three-phonon replicas related to E(LO, TO) and B2(LO, TO) vibrational modes in chalcopyrite structure. It was suggested that the strong interaction between excitons and optical phonons took place in obtained CuAlS2 powder.

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Naiki, Hiroyuki, Hidetoshi Oikawa, and Sadahiro Masuo. "Modification of emission photon statistics from single quantum dots using metal/SiO2 core/shell nanostructures." Photochemical & Photobiological Sciences 16, no. 4 (2017): 489–98. http://dx.doi.org/10.1039/c6pp00342g.

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Kotwal, Ashutosh V., and Bodhitha Jayatilaka. "Comparison of horace and photos Algorithms for Multiphoton Emission in the Context ofWBoson Mass Measurement." Advances in High Energy Physics 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/1615081.

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Wboson mass measurement is sensitive to QED radiative corrections due to virtual photon loops and real photon emission. The largest shift in the measured mass, which depends on the transverse momentum spectrum of the charged lepton from the boson decay, is caused by the emission of real photons from the final-state lepton. There are a number of calculations and codes available to model the final-state photon emission. We perform a detailed study, comparing the results fromhoraceandphotosimplementations of the final-state multiphoton emission in the context of a direct measurement ofWboson mass at Tevatron. Mass fits are performed using a simulation of the CDF II detector.

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Zhang, H., I. M. Christie, M. Petropoulou, J. M. Rueda-Becerril, and D. Giannios. "Inverse Compton signatures of gamma-ray burst afterglows." Monthly Notices of the Royal Astronomical Society 496, no. 1 (June 5, 2020): 974–86. http://dx.doi.org/10.1093/mnras/staa1583.

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ABSTRACT The afterglow emission from gamma-ray bursts (GRBs) is believed to originate from a relativistic blast wave driven into the circumburst medium. Although the afterglow emission from radio up to X-ray frequencies is thought to originate from synchrotron radiation emitted by relativistic, non-thermal electrons accelerated by the blast wave, the origin of the emission at high energies (HE; ≳GeV) remains uncertain. The recent detection of sub-TeV emission from GRB 190114C by the Major Atmospheric Gamma Imaging Cherenkov Telescopes (MAGIC) raises further debate on what powers the very high energy (VHE; ≳300 GeV) emission. Here, we explore the inverse Compton scenario as a candidate for the HE and VHE emissions, considering two sources of seed photons for scattering: synchrotron photons from the blast wave (synchrotron self-Compton or SSC) and isotropic photon fields external to the blast wave (external Compton). For each case, we compute the multiwavelength afterglow spectra and light curves. We find that SSC will dominate particle cooling and the GeV emission, unless a dense ambient infrared photon field, typical of star-forming regions, is present. Additionally, considering the extragalactic background light attenuation, we discuss the detectability of VHE afterglows by existing and future gamma-ray instruments for a wide range of model parameters. Studying GRB 190114C, we find that its afterglow emission in the Fermi-Large Area Telescope (LAT) band is synchrotron dominated. The late-time Fermi-LAT measurement (i.e. t ∼ 104 s), and the MAGIC observation also set an upper limit on the energy density of a putative external infrared photon field (i.e. ${\lesssim} 3\times 10^{-9}\, {\rm erg\, cm^{-3}}$), making the inverse Compton dominant in the sub-TeV energies.

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Chen, Liang, Da Huang, and Chao-Qiang Geng. "Effects of stimulated emission and superradiant growth of non-spherical axion cluster." Journal of Cosmology and Astroparticle Physics 2024, no. 05 (May 1, 2024): 132. http://dx.doi.org/10.1088/1475-7516/2024/05/132.

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Abstract We explore the stimulated emission of photons in non-spherical axion clusters with or without the axion source from the superradiance of a rotating black hole (BH). In particular, we focus on the cluster with the initial axion distribution in the (l,m)=(1,1) mode which mimics the shape of an axion cloud induced by the BH superradiance. After establishing the hierarchy of Boltzmann equations governing a general non-spherical axion-photon system, we examine the evolution of photon and axion distributions in the cluster and possible stimulated emission signals. In the case without the axion source, the resultant signal would be a single photon pulse. As for the system with the BH superradiance as the axion source, multiple pulses are predicted. We also show that, for the latter case, the combined effects of stimulated emissions and the axion production from the BH superradiance could reach a balance where the axion cluster becomes uniformly and spherically distributed. Due to the energy and temporal characteristics of the obtained pulses, we demonstrate that the stimulated emissions from the axion cluster with axions sourced by the BH superradiance provide a candidate explanation to the observed fast radio bursts.

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Ma, Xuedan, Nicolai F. Hartmann, Kirill A. Velizhanin, Jon K. S. Baldwin, Lyudmyla Adamska, Sergei Tretiak, Stephen K. Doorn, and Han Htoon. "Multi-exciton emission from solitary dopant states of carbon nanotubes." Nanoscale 9, no. 42 (2017): 16143–48. http://dx.doi.org/10.1039/c7nr06661a.

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By separating the photons from slow and fast decays of single- and multi-excitons in a time gated 2^nd order photon correlation experiment, we show that solitary oxygen dopants of carbon nanotubes allow emission of photon pairs with ∼44% of single exciton quantum yield.

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Toledo, J., A. Post, and J. F. Plaza. "Measurement of the C12A7:e- thermionic emission enhancement due to photon exposure." Journal of Physics: Conference Series 2526, no. 1 (June 1, 2023): 012111. http://dx.doi.org/10.1088/1742-6596/2526/1/012111.

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Abstract In this work, a test set-up device is designed, developed and manufactured to perform a direct measurement of the current emission enhancement that the photon absorption can bring to the thermionic emission in a Photon-Enhanced Thermionic Emission Device (PETED) where the C12A7:e- electride is used as the semiconductor due to its low work function value of 2.4 eV. Even though the measured thermionic emission starts at low operational temperatures, obtaining for example a current density emission of 5 mA/cm2 at 500 °C, there is barely an increase of 1% in the current emission when the device is exposed to a source of photons. This effect is mainly due to the presence of a dielectric layer at the material surface, which acts as a barrier, reduces the current enhancement effect from photon excitation, and drives to a limited efficiency of 27 μA/cm2/W.

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Mustafa, Saba, Hadi J. M. Al-Agealy, and Ahmad A. Al-Rubaiee. "Simple Scenario of Photons Emission from Anti Charm–Gluon Interaction using QCD Theory." Journal of Kufa-Physics 15, no. 01 (June 28, 2023): 85–98. http://dx.doi.org/10.31257/2018/jkp/2023/v15.i01.11300.

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In this work, the chromodynamics (QCD) theory was used to investigate the photon rate which was produced in interactions of anti-charm with gluon. The simple quantum scenario theory was implemented to give the rate equation that describes the collision of quark and gluon at a chemical potential .The photon emission rate was evaluated from the anti-charm-gluon interaction of the cg → dγ collision at the temperature of the system in the range of 180 - 360 MeV with different critical temperatures (e.g. 116.575, 139.891, 157.377 and 174.863 MeV) with photons energy GeV under the assumption that fugacity of quark and gluon are =0.08 and =0.02 respectively . The photon rate increases with decreasing the coupling of quark and gluon according to a decrease in the temperature of the system from 360 MeV to 180 MeV. The photon emission spectrum was calculated and discussed using a photon energy of 1GeV to 10GeV with different critical temperatures. In terms of QCD theory, the quantitative accomplishment was made for a unique six-flavor number nf = 4 + 2 of photon emission. The photon rate reaches minimum with photon energy E=10 GeV, it reﬂects the less coupling for the cg → dγ interaction.

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Storey, Michelle C., J. G. Greenhill, and T. Kotani. "Investigating Pulse Morphology in GX 1+4." Publications of the Astronomical Society of Australia 15, no. 2 (1998): 217–21. http://dx.doi.org/10.1071/as98217.

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AbstractObservational and theoretical evidence points to the existence of an unusually high magnetic field on GX 1+4. The pulsar is thus an ideal laboratory for studying two-photon cyclotron emission, an important source of photons of frequency significantly less than the cyclotron frequency in X-ray pulsars. Low-frequency approximations to the two-photon cyclotron emission transition probabilities are derived. These are used to calculate the theoretical opening angle of the double-humped pulse shape predicted by the two-photon cyclotron emission model. The theoretical pulse shape, incorporating the effects of gravitational light bending, is compared with observations of GX 1+4. Observed light curves have opening angles consistent with the theoretically predicted maximum value.

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DWIVEDI, Y., and S. B. RAI. "PHOTON AVALANCHE UPCONVERSION EMISSION IN Ho:Gd2O3 NANOPHOSPHOR." International Journal of Nanoscience 10, no. 04n05 (August 2011): 925–28. http://dx.doi.org/10.1142/s0219581x11008782.

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This paper report, the structural and spectroscopic properties of Gd2O3 nano-phosphor activated with Ho3+ ions. XRD, SEM and TEM techniques have been used for the structural characterizations. The phosphor contains spherical nanocrystallites with uniform size of ~40 nm. Enhanced IR to green and red photon avalanche upconversion is reported under 976 nm laser excitations. Further, annealing shows a significant improvement in emission intensity. Temporal evolution of upconversion emission intensity were measured which suggests the photon-avalanche mechanism is responsible for the upconversion process. The enhancement of emission was explained and the photo-physics involved is correlated with the unique structural properties of the crystallites formed.

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Shiota, Tadashi, Yasuo Toyoshima, Kouichi Yasuda, and Yohtaro Matsuo. "Gas Pressure Dependence of Photon Emission Accompanying Fracture of Polycrystalline MgO in Nitrogen." Key Engineering Materials 317-318 (August 2006): 313–16. http://dx.doi.org/10.4028/www.scientific.net/kem.317-318.313.

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The photon emission accompanying fracture of a polycrystalline MgO was investigated at room temperature under N2 gas pressures from 10-4 to 105 Pa. At fracture, the ultraviolet, visible and infrared photon emissions instantaneously increased, and then rapidly decreased in most of the experimental conditions. However, in a N2 gas pressure of around 100 Pa, their peak counts lasted for about 10 milliseconds, and the amount of the UV photon emission was fifteen times larger than those obtained in the other N2 gas pressures. This abrupt increment in the emission was explained by the luminescence due to N2 gas discharge according to the classical Townsend’s theory. In conclusion, the photon emission accompanying fracture of a polycrystalline MgO mainly originated from the excited defects as reported by the authors previously, but the N2 gas discharge had a supplementary effect on the emission around a specific N2 gas pressure.

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Du, Linfeng, Paul Ruchhoeft, Demetre J. Economou, and Vincent M. Donnelly. "Absolute measurement of vacuum ultraviolet photon flux in an inductively coupled plasma using a Au thin film." Journal of Vacuum Science & Technology B 40, no. 2 (March 2022): 022206. http://dx.doi.org/10.1116/6.0001709.

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A new method for absolute measurement of the vacuum ultraviolet (VUV) photon flux at the edge of a plasma is described. The light produced by the plasma was allowed to strike a negatively biased, gold-coated copper substrate remote from the plasma. The resulting photoelectron emission current was measured, and the absolute photon flux was then found from the known photoelectron yield of Au. The method was used to quantify the amount of VUV light produced by an Ar/He inductively coupled plasma (ICP). Strong emissions at 104.82 and 106.67 nm, corresponding to the 1s2 and 1s4 resonant states of Ar, were observed. The maximum, integrated VUV photon flux measured at the remote location was 3.2 × 1013 photons/cm2 s. This was estimated to correspond to a flux of 5 × 1015 photons/cm2 s at the edge of the ICP, in the range of reported values under similar conditions.

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Andrianov, Alexander, Roberto Soldati, and Dmitri Vassilevich. "Emission of Photons by Quasiparticles in Weyl Semimetals." Symmetry 12, no. 5 (May 25, 2020): 869. http://dx.doi.org/10.3390/sym12050869.

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D′Elia, Alessandro, Alessio Rettaroli, Fabio Chiarello, Daniele Di Gioacchino, Emanuele Enrico, Luca Fasolo, Carlo Ligi, et al. "Microwave Photon Emission in Superconducting Circuits." Instruments 7, no. 4 (October 30, 2023): 36. http://dx.doi.org/10.3390/instruments7040036.

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Quantum computing requires a novel approach to store data as quantum states, opposite to classical bits. One of the most promising candidates is entangled photons. In this manuscript, we show the photon emission in the range of microwave frequencies of three different types of superconducting circuits, a SQUID, a JPA, and a JTWPA, often used as low-noise parametric amplifiers. These devices can be operated as sources of entangled photons. We report the experimental protocol used to produce and measure microwave radiation from these circuits, as well as data simulations. The collected spectra are obtained by performing single-tone measurements with a direct rf pump on the devices; the output spectra at low powers (below −100 dBm) are well interpreted by the dynamical Casimir model, while at high powers (above −100 dBm) the system is well described by the Autler–Townes fluorescence of a three-level atom.

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Kang, Nam Lyong, and Sang Don Choi. "Projection-Reduction Approach to Optical Conductivities for an Electron-Phonon System and Their Diagram Representation." ISRN Condensed Matter Physics 2014 (April 7, 2014): 1–23. http://dx.doi.org/10.1155/2014/719120.

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Utilizing state-dependent projection operators and the Kang-Choi reduction identities, we derive the linear, first, and second-order nonlinear optical conductivities for an electron system interacting with phonons. The lineshape functions included in the conductivity tensors satisfy “the population criterion” saying that the Fermi distribution functions for electrons and Planck distribution functions for phonons should be combined in multiplicative forms. The results also contain energy denominator factors enforcing the energy conservation as well as interaction factors describing electron-phonon interaction properly. Therefore, the phonon absorption and emission processes as well as photon absorption and emission processes in all electron transition processes can be presented in an organized manner and the results can be represented in diagrams that can model the quantum dynamics of electrons in a solid.

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Diguna, Lina Jaya, Yudi Darma, and Muhammad Danang Birowosuto. "The coupling of single-photon exciton–biexciton quantum dot and cavity." Journal of Nonlinear Optical Physics & Materials 26, no. 03 (September 2017): 1750029. http://dx.doi.org/10.1142/s0218863517500291.

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We investigate the influence of multiple excitons on the photon emission properties of a quantum dot (QD)-cavity system via the master equation for the density matrix. We show that in the intermediate to strong coupling regimes, the multiple excitons lead to the suppressed QD emissions as well as the absence of anti-crossing near zero detuning, arising from the interaction between the multiple excitons and cavity. Furthermore, we analyze the role of the cavity-biexciton detuning in the photon emission properties of cavity and exciton through the second-order correlation function. The small cavity-biexciton detuning yields the significant Purcell effect and the high probability of single photon emissions. The proposed model offers the fundamental approach in developing efficient single-photon emitting devices.

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Formenti, A., M. Galbiati, and M. Passoni. "Modeling and simulations of ultra-intense laser-driven bremsstrahlung with double-layer targets." Plasma Physics and Controlled Fusion 64, no. 4 (February 28, 2022): 044009. http://dx.doi.org/10.1088/1361-6587/ac4fce.

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Abstract High-energy bremsstrahlung emission can occur owing to electron scattering in the nuclei or ions Coulomb field following the relativistic-electron generation in high-intensity laser interaction with plasmas. Such emission of photons in the keV–MeV energy range is of interest to characterize the relativistic-electron populations and develop laser-based photons sources. Even if it is a well-established and widely studied emission process, its modeling in laser-plasma scenarios needs further investigation. Moreover, advanced near-critical double-layer targets (DLTs), consisting in a low-density foam deposited on a thin solid substrate, have never been explored extensively for bremsstrahlung photon emission. Therefore, in this paper, we show the rationale, advantages, limitations, application regime, and complementarity of different modeling approaches and apply them to the unconventional configuration based on DLTs. We use multi-dimensional particle-in-cell (PIC) simulations coupled with a Monte Carlo strategy to simulate bremsstrahlung in two ways: integrated into the PIC loop itself or after the simulation with two separate codes. We also use simplified semi-analytical relations to retrieve the photon properties starting only from information on the relativistic electrons. With these tools, we investigate bremsstrahlung emission when an ultra-intense laser (0.8 µm wavelength, 30 fs duration, a 0 = 20 and 3 µm waist) interacts with DLTs having different properties. Despite some limitations of the numerical tools, we find that all approaches significantly agree on the characteristics of ~1–100 MeV photon emission. This points to the possibility of adopting the different modeling approaches in a complementary way while at the same time identifying the best suited for a specific scenario. Regardless, DLTs appear to overall boost the high energy photon emission while at the same time enabling control of the emission itself.

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Younis, Taghreed A., and Hadi J. M. Al-Agealy. "Study and Investigation of Hard Photons Emission in Heavy Ion Collisions." NeuroQuantology 19, no. 2 (March 20, 2021): 61–65. http://dx.doi.org/10.14704/nq.2021.19.2.nq21018.

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This work involves hard photon rate production from quark -gluon plasma QGP interaction in heavy ion collision. Using a quantum chromodynamic model to investigate and calculation of photons rate in 𝑐𝑔 → 𝑠𝑔𝛾 system due to strength coupling, photons rate, temperature of system, flavor number and critical. The photons rate production computed using the perturbative strength models for QGP interactions. The strength coupling was function of temperature of system, flavor number and critical temperature. Its influenced by force with temperature of system, its increased with decreased the temperature and vice versa. The strength coupling has used to examine the confinement and deconfinement of quarks in QGP properties and influence on the photon rate production. In our approach, we calculate the photons rate depending on the strength coupling, photons rate and temperature of system with other factors. The results plotted as a function of the photons energy. The photons rate was decreased with increased temperature and increased with decreased with strength coupling.

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Crosignani, Viera, Sohail Jahid, Alexander Dvornikov, and Enrico Gratton. "Deep tissue imaging by enhanced photon collection." Journal of Innovative Optical Health Sciences 07, no. 05 (September 2014): 1450034. http://dx.doi.org/10.1142/s1793545814500345.

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We have developed a two-photon fluorescence microscope capable of imaging up to 4mm in turbid media with micron resolution. The key feature of this instrument is the innovative detector, capable of collecting emission photons from a wider surface area of the sample than detectors in traditional two-photon microscopes. This detection scheme is extremely efficient in the collection of emitted photons scattered by turbid media which allows eight fold increase in the imaging depth when compared with conventional two-photon microscopes. Furthermore, this system also has in-depth fluorescence lifetime imaging microscopy (FLIM) imaging capability which increases image contrast. The detection scheme captures emission light in a transmission configuration, making it extremely efficient for the detection of second harmonic generation (SHG) signals, which is generally forward propagating. Here we present imaging experiments of tissue phantoms and in vivo and ex vivo biological tissue performed with this microscope.

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Allemand, A., F. Kulzer, B. Mahler, C. Dujardin, and J. Houel. "Optical properties of individual CdS/CdSe/CdS nanocrystals: spherical quantum wells as single-photon sources." Nanotechnology 33, no. 27 (April 12, 2022): 275703. http://dx.doi.org/10.1088/1361-6528/ac5ee3.

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Abstract We have synthesized CdS(1.3 nm)/CdSe(1.7 nm)/CdS(3.4 nm) spherical quantum wells (SQWs) with a diameter of 13 nm and demonstrated the first photon-antibunching from their emission, labelling them as single-photon sources. Antibunching survives even at high excitation intensities, ruling-out strong emission from the bi-exciton. For the largest intensities, antibunching coupled to spectral measurements reveal the signature of a blue-shifted emission, associated to an irreversible photo-aging effect. A statistical analysis over 26 SQWs demonstrates a moderate correlation between the energy of the main and the blue-shifted emission. Intensity-timetraces recorded on 28 single SQWs show weak blinking, with a median time spent in the bright state of 89%. Their emission decay reveals a complex dynamic with either three or four exponential components. We assigned three of them to the neutral and singly-charged excitons and the slowest to defect emission. While SQWs have been initially designed for laser-oriented applications, we demonstrate that they can serve as efficient single-photon sources.

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Piao, Daqing. "Phenomenological Interpretations of Some Somatic Temporal and Spatial Patterns of Biophoton Emission in Humans." Journal of Scientific Exploration 35, no. 2 (June 15, 2021): 345–82. http://dx.doi.org/10.31275/20211685.

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Biophoton emission remains controversial. The photo-genic origin of biophoton has been attributed to the oxidative stress or free radical production. However, there are considerable gaps in quantitative understanding of biophoton emission. I propose an analytical hypothesis for interpreting a few patterns of steady-state biophoton emission of human, including the dependency on age, the diurnal variation, and the geometric asymmetry associated with serious asymmetrical pathological conditions. The hypothesis is based on an alternative form of energy state, termed vivo-nergy, which is associated with only metabolically active organisms that are also under neuronal control. The hypothesis projects a decrease of the vivo-nergy in human during growth beyond puberty. The hypothesis also proposes a modification of the vivo-nergy by the phases of systematic or homeostatic physiology. The hypothesis further postulates that the deviation of the physiology-modified vivo-nergy from the pre-puberty level is deteriorated by acquired organ-specific pathological conditions. A temporal differential change of vivo-nergy is hypothesized to proportionally modulate oxidative stress that functions as the physical source of biophoton emission. The resulted steady-state diffusion of the photon emitted from a photo-genic source in a human geometry simplified as a homogeneous spherical domain is modeled by photon diffusion principles incorporating an extrapolated zero-boundary condition. The age and systematic physiology combined determines the intensity of the centered physiological steady-state photo-genic source. An acquired pathology sets both the intensity and the off-center position of the pathological steady-state photo-genic source. When the age-commemorated, physiology-commanded, and pathology-controlled modifications of the steady-state photo-genetic sources are implemented in the photon diffusion model, the photon fluence rate at the surface of the human-representing spherical domain reveals the patterns on age, the temporal variation corresponding to systematic physiology, and the geometric asymmetry associated with significant asymmetric pathological condition as reported for spontaneous biophoton emission. The hypothesis, as it provides conveniences for quantitative estimation of biophoton emission patterns, will be extended in future works towards interpreting the temporal characteristics of biophoton emission under stimulation.

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Reig, Pablo, and Nikolaos D. Kylafis. "Inclination effects on the X-ray emission of Galactic black-hole binaries." Astronomy & Astrophysics 625 (May 2019): A90. http://dx.doi.org/10.1051/0004-6361/201935070.

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Context. Galactic black-hole X-ray binaries (BHBs) emit a compact, optically thick, mildly relativistic radio jet when they are in hard and hard-intermediate states. In these states, BHBs exhibit a correlation between the time lag of hard with respect to softer photons and the photon index of the power law component that characterizes the X-ray spectral continuum above ∼10 keV. The correlation, however, shows large scatter. In recent years, several works have brought to light the importance of taking into account the inclination of the systems to understand the X-ray and radio phenomenology of BHBs. Aims. Our objective is to investigate the role that the inclination plays on the correlation between the time lag and photon index. Methods. We obtained RXTE energy spectra and light curves of a sample of BHBs with different inclination angles. We computed the photon index and the time lag between hard and soft photons and performed a correlation and linear regression analysis of the two variables. We also computed energy spectra and light curves of BHBs using the Monte Carlo technique that reproduces the process of Comptonization in the jet. We account for the inclination effects by recording the photons that escape from the jet at different angles. From the simulated light curves and spectra we obtained model-dependent photon index and time lags, which we compared with those obtained from the real data. Results. We find that the correlation between the time lag and photon index is tight in low-inclination systems and becomes weaker in high-inclination systems. The amplitude of the lags is also larger at low- and intermediate-inclination angles than at high inclination. We also find that the photon index and time lag, obtained from the simulated spectra and light curves, also follow different relationships for different inclination angle ranges. Our jet model reproduces the observations remarkably well. The same set of models that reproduces the correlation for the low-inclination systems, also accounts for the correlation for intermediate- and high-inclination systems fairly well. Conclusions. The large dispersion observed in the time lag – photon index correlation in BHBs can naturally be explained as an inclination effect. Comptonization in the jet explains the steeper dependence of the lags on the photon index in low- and intermediate-inclination systems than in high-inclination systems.

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Dalacu, Dan, Philip J. Poole, and Robin L. Williams. "Tailoring the Geometry of Bottom-Up Nanowires: Application to High Efficiency Single Photon Sources." Nanomaterials 11, no. 5 (May 1, 2021): 1201. http://dx.doi.org/10.3390/nano11051201.

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For nanowire-based sources of non-classical light, the rate at which photons are generated and the ability to efficiently collect them are determined by the nanowire geometry. Using selective-area vapour-liquid-solid epitaxy, we show how it is possible to control the nanowire geometry and tailor it to optimise device performance. High efficiency single photon generation with negligible multi-photon emission is demonstrated using a quantum dot embedded in a nanowire having a geometry tailored to optimise both collection efficiency and emission rate.

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Protheroe, R. J. "Factors Determining Variability Time in Active Galactic Nucleus Jets." Publications of the Astronomical Society of Australia 19, no. 4 (2002): 486–98. http://dx.doi.org/10.1071/as02008.

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AbstractThe relationship between observed variability time and emission region geometry is explored for the case of emission by relativistic jets.The approximate formula for the jet-frame size of the emission region, R′ = DcΔtobs, is shown to lead to large systematic errors when used together with observed luminosity and assumed or estimated Doppler factor D to estimate the jet-frame photon energy density. These results have implications for AGN models in which low-energy photons are targets for interaction of high energy particles and photons, e.g. synchrotron-self Compton models and hadronic blazar models, as well as models of intraday variable sources in which the photon energy density imposes a brightness temperature limit through Compton scattering.The actual relationship between emission region geometry and observed variability is discussed for a variety of geometries including cylinders, spheroids, bent, helical and conical jet structures, and intrinsic variability models including shock excitation. The effects of time delays due to finite particle acceleration and radiation timescales are also discussed.

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Mustafa Hussein, Saba, Hadi J. M. AL-Agealy, and Al-Rubaiee A. A. "Theoretical Analysis Of The Photon Production Rate in the Quark-Gluon Interaction According To The Quantum Cromodynamic QCD Theory." Ibn AL-Haitham Journal For Pure and Applied Sciences 36, no. 3 (July 20, 2023): 109–23. http://dx.doi.org/10.30526/36.3.3084.

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In this work, we have used the QCD dynamic scenario of the quark gluon interaction to investigate and study photon emission theoretically based on quantum theory. The QCD theory is implemented by deriving the photon emission rate equation of the state of ideal QGP at a chemical potential. The photon rate of the quark-gluon interaction has to be calculated for the anti up-gluon interaction in the g → γ system at the temperature of system with critical temperature ( 132.38, , and 198.57) MeV and photon energy ( GeV. We investigated a significant effect of critical temperature, strength coupling, and photon energy on the photon rate contribution. Here, the increased photon emission rate and decreased strength coupling of the quark-gluon reaction due to the decrease in temperature of the system from 360 MeV to 180 MeV are predicted. Photon energy in the range (1 to 10) GeV and the rate spectrum of four varieties of critical temperatures are presented. The interesting point in our results is the minimum value of photon rate, especially in the photon energy E=10 GeV of ﬂavor which reflects the poor coupling between quark and gluon in the the g → γ system which was already expected. The features of QCD results are achieved in the case of ﬂavors for the photon energy E=1 to 10 GeV, the strength coupling and the photo meason rate are calculated theoretically. We can notice that the asymptotic behavior, which was characterized by a hadronic phase limit, will be satisfied.

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Galimov, Aidar, Michail Bobrov, Maxim Rakhlin, Yuriy Serov, Dmitrii Kazanov, Alexey Veretennikov, Grigory Klimko, et al. "Towards Bright Single-Photon Emission in Elliptical Micropillars." Nanomaterials 13, no. 9 (May 8, 2023): 1572. http://dx.doi.org/10.3390/nano13091572.

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In recent years, single-photon sources (SPSs) based on the emission of a single semiconductor quantum dot (QD) have been actively developed. While the purity and indistinguishability of single photons are already close to ideal values, the high brightness of SPSs remains a challenge. The widely used resonant excitation with cross-polarization filtering usually leads to at least a two-fold reduction in the single-photon counts rate, since single-photon emission is usually unpolarized, or its polarization state is close to that of the exciting laser. One of the solutions is the use of polarization-selective microcavities, which allows one to redirect most of the QD emission to a specific polarization determined by the optical mode of the microcavity. In the present work, elliptical micropillars with distributed Bragg reflectors are investigated theoretically and experimentally as a promising design of such polarization-selective microcavities. The impact of ellipticity, ellipse area and verticality of the side walls on the splitting of the optical fundamental mode is investigated. The study of the near-field pattern allows us to detect the presence of higher-order optical modes, which are classified theoretically. The possibility of obtaining strongly polarized single-photon QD radiation associated with the short-wavelength fundamental cavity mode is shown.

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Zaidi, H. R. "Two-photon emission spectrum." Physical Review A 36, no. 8 (October 1, 1987): 3904–8. http://dx.doi.org/10.1103/physreva.36.3904.

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Fujii, Hirotsugu, Kazunori Itakura, and Chiho Nonaka. "Photon emission at hadronization." Nuclear Physics A 967 (November 2017): 704–7. http://dx.doi.org/10.1016/j.nuclphysa.2017.06.045.

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Rossi, P., B. L. Doyle, J. C. Banks, A. Battistella, G. Gennaro, F. D. McDaniel, M. Mellon, E. Vittone, G. Vizkelethy, and N. D. Wing. "Ion photon emission microscopy." Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 210 (September 2003): 123–28. http://dx.doi.org/10.1016/s0168-583x(03)01081-4.

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Krasinski, Jerzy, Daniel J. Gauthier, Michelle S. Malcuit, and Robert W. Boyd. "Two-photon conical emission." Optics Communications 54, no. 4 (June 1985): 241–45. http://dx.doi.org/10.1016/0030-4018(85)90300-1.

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Nasiri Avanaki, K., and George C. Schatz. "Generation of entangled-photons by a quantum dot cascade source in polarized cavities: Using cavity resonances to boost signals and preserve the entanglements." Journal of Chemical Physics 158, no. 14 (April 14, 2023): 144106. http://dx.doi.org/10.1063/5.0144364.

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Motivated by recent advances in the development of single photon emitters for quantum information sciences, here we design and formulate a quantum cascade model that describes cascade emission by a quantum dot (QD) in a cavity structure while preserving entanglement that stores information needed for single photon emission. The theoretical approach is based on a photonic structure that consists of two orthogonal cavities in which resonance with either the first or second of the two emitted photons is possible, leading to amplification and rerouting of the entangled light. The cavity–QD scheme uses a four-level cascade emitter that involves three levels for each polarization, leading to two spatially entangled photons for each polarization. By solving the Schrodinger equation, we identify the characteristic properties of the system, which can be used in conjunction with optimization techniques to achieve the “best” design relative to a set of prioritized criteria or constraints in our optical system. The theoretical investigations include an analysis of emission spectra in addition to the joint spectral density profile, and the results demonstrate the ability of the cavities to act as frequency filters for the photons that make up the entanglements and to modify entanglement properties. The results provide new opportunities for the experimental design and engineering of on-demand single photon sources.

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Eied, A. A. "Emission spectrum for a multi-photon Ξ-type three-level atom driven by a binomial field with nonlinearities." Canadian Journal of Physics 93, no. 11 (November 2015): 1375–81. http://dx.doi.org/10.1139/cjp-2014-0602.

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A treatment of a multi-photon Ξ-type three-level atom interacting with a single-mode field in a cavity, taking explicitly the existence of forms of nonlinearities of both the field and the intensity-dependent atom–field coupling into account. Analytical expressions of the emission spectrum are presented using the dressed states of the system. The characteristics of the emission spectrum, considering the field to be initially in a binomial state, are exhibited. The effects of the photon multiplicities, mean number of photons, detuning, and the nonlinearities on the spectrum are investigated.

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Yuh, Jih-Young, Shan-Wei Lin, Liang-Jen Huang, Hok-Sum Fung, Long-Life Lee, Yu-Joung Chen, Chiu-Ping Cheng, Yi-Ying Chin, and Hong-Ji Lin. "Upgrade of beamline BL08B at Taiwan Light Source from a photon-BPM to a double-grating SGM beamline." Journal of Synchrotron Radiation 22, no. 5 (August 8, 2015): 1312–18. http://dx.doi.org/10.1107/s1600577515014009.

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During the last 20 years, beamline BL08B has been upgraded step by step from a photon beam-position monitor (BPM) to a testing beamline and a single-grating beamline that enables experiments to record X-ray photo-emission spectra (XPS) and X-ray absorption spectra (XAS) for research in solar physics, organic semiconductor materials and spinel oxides, with soft X-ray photon energies in the range 300–1000 eV. Demands for photon energy to extend to the extreme ultraviolet region for applications in nano-fabrication and topological thin films are increasing. The basic spherical-grating monochromator beamline was again upgraded by adding a second grating that delivers photons of energy from 80 to 420 eV. Four end-stations were designed for experiments with XPS, XAS, interstellar photoprocess systems (IPS) and extreme-ultraviolet lithography (EUVL) in the scheduled beam time. The data from these experiments show a large count rate in core levels probed and excellent statistics on background normalization in theL-edge adsorption spectrum.

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MIKHEEV, N. V., A. YA. PARKHOMENKO, and L. A. VASSILEVSKAYA. "AXION DECAY OF A PHOTON IN AN EXTERNAL ELECTROMAGNETIC FIELD." Modern Physics Letters A 13, no. 23 (July 30, 1998): 1899–905. http://dx.doi.org/10.1142/s021773239800200x.

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An interaction of a pseudoscalar particle with two photons induced by an external electromagnetic field is used to study the photon decay γ→γa where a is a pseudoscalar particle associated with the Peccei–Quinn U(1) symmetry. The field-induced axion emission by photon is analyzed as a possible source of energy losses by astrophysical objects.

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Journal articles on the topic 'Photon emission'

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