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Perry, Ian Richard. "Investigations into ytterbium, ytterbium-erbium and thulium-doped silica-based fibre lasers." Thesis, University of Southampton, 1991. https://eprints.soton.ac.uk/427927/.
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Barber, Zeb. "Ytterbium optical lattice clock." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3284459.
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Dunfield, Kari. "Laser spectroscopy of ytterbium monofluoride." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23791.pdf.
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Campbell, Jonathan A. (Jonathan Alan). "Surface trap for ytterbium ions." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36816.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2006.<br>Includes bibliographical references (leaves 41-42).<br>We conducted an experiment to load a shallow planar ion trap from a cold atom source of Ytterbium using photoionization. The surface trap consisted of a three-rod radio frequency Paul trap fabricated using standard printed circuit board techniques. The cold atom source was an isotope-selective magneto-optical trap of naturally-occurring Yb isotopes. The confining beams were provided by commercially-available ultra-violet diode lasers locked to an atomic reference using the Dichroic Atomic Vapor Laser Lock technique. We used photoionization from the Yb magneto-optical trap located within the region of the ion trapping potential.<br>by Jonathan A. Campbell.<br>Ph.D.
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Ata, Filiz. "Ytterbium- und gold-katalysierte Reaktionen /." Berlin : Mbv, 2009. http://d-nb.info/995894973/04.
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Maruyama, Reina. "Optical trapping of ytterbium atoms /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/9778.
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Prochnow, Oliver. "Rauscheigenschaften von passiv modengekoppelten Ytterbium-Faserlasern." Göttingen Cuvillier, 2010. http://d-nb.info/1000129217/04.
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Roberts, Matthew. "Spectroscopy of a single ytterbium ion." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443460.
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Castaneda, Juan Carlos Hernandez. "Ytterbium fibre laser cutting of wood." Thesis, University of Manchester, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520761.
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This Ph.D. project provides for the first time the basic characteristics of fibre laser interaction with pine wood in dry and wet state. Fibre laser has gained importance in the laser material processing market as it presents an advanced technology. It is compact, reliable and more efficient than CO2 and Nd:YAG lasers. The high quality laser beam generated is currently in the kilowatt power level suitable for cutting operations. Furthermore, this laser system needs low maintenance and it has very long working life. It also presents the flexibility of fibre delivery, up to 200 meters from the laser source. Three major experiments were performed: laser cutting of dry pine wood with multiple passes of the laser beam; the laser cutting of wet and dry pine wood; analysing the effect of single and dual assisting gas jet(s) in the fibre laser cutting process. In each experiment, the main process parameters and their interactions affecting the process were discussed. Furthermore, the application of a desirability equation provided the optimal combination of the parameters involved (within the experimental window tested) to maximise the yield and the quality of the laser cutting operation. The effect of the assistant gas jet(s) was further analysed with a computational fluid dynamic (CFD) model, which information clarified its/their action in ejecting fumes and combusted materials in the process. Finally, an application study of Ytterbium fibre laser cutting of hardwood branches was performed; the results obtained were compared with CO2 laser cutting results reported in the literature.
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Hin, Shane Yannick Lo Fan. "Reductive homocoupling from samarium to ytterbium." Thesis, University of Liverpool, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.507175.
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Peters, Rigo. "Ytterbium-dotierte Sesquioxide als hocheffiziente Lasermaterialien." Aachen Shaker, 2009. http://d-nb.info/996984313/04.
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Loftus, Thomas Howard. "Laser cooling and trapping of atomic Ytterbium /." view abstract or download file of text, 2001. http://wwwlib.umi.com/cr/uoregon/fullcit?p3018379.
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Thesis (Ph. D.)--University of Oregon, 2001.<br>Typescript. Includes vita and abstract. Includes bibliographical references (leaves 263-280). Also available for download via the World Wide Web; free to University of Oregon users.
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Yan, Xingzhao. "Ytterbium doped tantalum pentoxide nanowire waveguide lasers." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/424429/.
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Ytterbium (Yb) has been widely studied in several host materials and device forms due to its broad gain bandwidth, long excited-state lifetime, and simple quasi-three energy level structure. Yb doped tantalum pentoxide (Yb:Ta<sub>2</sub>O<sub>5</sub>) waveguides are favorable for laser applications since Ta<sub>2</sub>O<sub>5</sub> has promising optical properties including high refractive index (≈2.1), wide transmission spectrum (350 nm to 9 μm) and suitability to host rare-earth ions. In this work, a nanowire waveguide design with taper and coupler section was demonstrated. Thin Yb:Ta<sub>2</sub>O<sub>5</sub> films were fabricated by plasma assisted reactive magnetron sputtering (PARMS) from high purity (99.999%) Ta metal and Yb metal targets at low temperature (< 70°C). The PARMS process allows Yb doping concentration to be easily adjusted, leading to a new flexible deposition method for not only Yb:Ta<sub>2</sub>O<sub>5</sub> but other doped materials. Nanoscale waveguide fabrication processes of strip loaded and buried channel waveguides on SiO<sub>2</sub> using electron beam lithography and inductively couple plasma reactive ion etching (RIE-ICP) were demonstrated and the first Yb:Ta<sub>2</sub>O<sub>5</sub> anisotropic RIE-ICP etching process was developed. Buried channel waveguide in polymer fabricated by nano-imprint was also demonstrated, offering low-cost and mass production of nanoscale waveguide. A 6.7 mm long strip loaded Yb:Ta<sub>2</sub>O<sub>5</sub> nanowire waveguide laser with 1.25 atomic percentage Yb doping concentration was demonstrated with a laser cavity formed of bare polished end facets only, with 12% Fresnel reflectivity. Single mode lasing was observed between 1015 nm and 1030 nm in strip loaded waveguides with nanowire of 400 nm width when end pumped by a 977 nm laser diode. The launched power threshold and the slope efficiency were measured to be ≈ 12 mW and ≈ 38%. The lasing wavelength of such waveguide can be switched by tuning the pump coupling position at the coupler section, implying a potential tuning mechanism. The results presented in this work demonstrate the capability of Yb:Ta<sub>2</sub>O<sub>5</sub> for being a waveguide laser, show the great potential for being used in mass-producible, CMOS compatible integrated optical circuits.
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Mostaed, Ali. "Atomic structure study of pyrochlore ytterbium titanate." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/96357/.
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There has been great interest in the magnetic behaviour of pyrochlore oxides with the general formula A2B2O7, in which rare-earth (A), and transition metal (B) cations are ordered on separate interpenetrating lattices of corner-sharing tetrahedra. Such materials exhibit behaviours including quantum spin-ice, (quantum) spin-liquid, and ordered magnetic ground states. Yb2Ti2O7 lies on the boundary between a number of competing magnetic ground states. Features in the low-temperature specific heat capacity that vary in sharpness and temperature from sample to sample suggest that in some cases the magnetic moments order, while in others the moments remain dynamic down to temperatures as low as ~16 mK. In this work, three different Yb2Ti2O7 single crystal samples, all grown by the optical floating zone technique but exhibiting quite different heat capacity behaviour, are studied by aberration-corrected scanning transmission microscopy (STEM). Atomic-scale energy-dispersive X-ray (EDX) analysis shows that a crystal with no specific heat anomaly has substitution of Yb atoms on Ti sites (“stuffing"). In fact, EDX analysis shows for the first time that “stuffing” of Yb (A) cations onto Ti (B) sites in the lattice can be observed directly in the pyrochlore structure. Moreover, I show that the detailed intensity distribution around the visible atom columns in annular dark field STEM images is sensitive to the presence of nearby atoms of low atomic number (in this case oxygen) and find significant differences between the samples that correlates both with their magnetic behaviour and measurements of Ti oxidation state using electron energy loss spectroscopy. These measurements support the view that the magnetic ground state of Yb2Ti2O7 is extremely sensitive to disorder. On the other hand, structural modification of ytterbium titanate by deviation from stoichiometry as well as electron irradiation is studied in this work. I show that Ti excess is accommodated by Yb cation vacancies while Yb excess is compensated by Yb interstitials. Furthermore, two MATLAB programs, Detect Columns and BurgersVectors, to analyse STEM images and calculate the dislocation density tensor of STEM images as well as their Burgers vector(s) are respectively introduced in this work.
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Morris, James. "Ytterbium and thulium sensitised holmium laser systems /." [S.l.] : [s.n.], 1994. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Kemp, Stefan Liam. "Laser cooling and optical trapping of Ytterbium." Thesis, Durham University, 2017. http://etheses.dur.ac.uk/12166/.
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This thesis presents the development of an experimental apparatus designed to investigate the ultracold collisional properties for mixtures of Cs and Yb, with a long-term view to the creation of ultracold CsYb molecules via indirect cooling methods. The unpaired electron spin that is inherent to molecules of this form gives rise to a magnetic dipole moment in addition to a ground state electric dipole moment. This enables extra control over molecular interactions and should enable the experimental simulation of spin lattice models. We focus on the implementation of a system designed to controllably laser cool and optically trap Yb. The first step in this system is the production of a magneto-optical trap (MOT) on the triplet 1S0 to 3P1 transition of Yb. With careful control over the cooling beam detunings and power, gravitational-assisted Doppler cooling allows samples of Yb to be prepared at 22 uK. This regime of enhanced Doppler cooling is investigated and proves to be a crucial step to ensuring good transfer of cold Yb to optical traps. The construction and characterisation of single and crossed beam optical dipole traps for Yb are discussed. The single beam optical trap has been used to verify a model for the optical trapping of Yb in its ground state. This trap has also been utilised as a tool for the measurement of the light shift on the 1S0 to 3P1 transition at a wavelength of 1070~nm. In the main experimental sequence, Yb atoms are loaded from the magneto-optical trap into the crossed optical dipole trap, allowing evaporative cooling ramps to quantum degeneracy to be performed. This highly-reproducible system typically forms Bose-Einstein condensates with 2 x 10^5 174Yb atoms. This thesis additionally reports on the progress made towards measurements of the interspecies scattering length for 133Cs and Yb isotopes. We present two approaches that are being developed in tandem: rethermalisation in a conservative trap, and two-photon photoassociation. Progress towards rethermalisation measurements has focussed on developing systems for the efficient transfer of Cs to an optical trap. For photoassociative measurements, a laser system has been developed and tested by producing one-photon photoassociation spectra of Cs2.
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Genevrier, Kévin. "Sources laser de forte énergie à base d'YbCaF2." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLO006/document.
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Ce travail de thèse a pour but le développement d'une source de pompe pour l'OPCPA nanoseconde qui sera inclus au sein du laser 10 PW Apollon.Dans un premier temps nous présentons les spécificités des systèmes multi-pétawatts et l'intérêt de l'amplification OPCPA pour ce type de systèmes. Le choix du matériau amplificateur Yb:CaF2 pour le développement de la source de pompe OPCPA est alors justifié après exposition de ses caractéristiques. Nous concluons enfin le premier chapitre par le design préliminaire de la source de pompe, design adapté aux spécificités du cristal Yb:CaF2.Dans le deuxième chapitre nous commençons par étudier les effets de lentilles thermiques et de dépolarisation du milieu amplificateur sous forte puissance de pompe et en fonction de la polarisation ou de l'orientation cristalline. Cela permet de valider le choix de l'orientation [111] du cristal amplificateur pour les systèmes de forte puissance. Dans un second temps nous nous attardons sur les céramiques Yb:CaF2 car leur isotropie mécanique présente a priori un intérêt pour les systèmes de forte puissance. Nous étudions les céramiques fabriquées par voie humide et mettons en évidence un fort échauffement limitant leur utilisation. Plusieurs hypothèses quant à cet effet sont alors discutées.Dans le dernier chapitre, nous complétons le design de la pompe par des simulations d'absorption, de gain et d'extraction d'énergie. Nous exposons enfin les résultats expérimentaux obtenus en amplification pour les architectures régénérative et multipassage géométrique, utilisant des cristaux Yb:CaF2 en configuration miroir actif<br>This PHD work is aiming at the development of a pump source for the nanosecond OPCPA of the 10 PW laser Apollon.First, we present the characteristics of the multipetawatt systems and the interest of OPCPA architecture for this type of systems. After detailing its characteristics, we then justify the choice of Yb:CaF2 as active media for the development of the nanosecond OPCPA pump source. We finally end the first chapter by the preliminary design of the pump source which is adapted to the specificities of the Yb:CaF2 crystal.The second chapter begins by the study of thermal lenses and thermal induced depolarization under high-power pumping in function of polarization or crystal orientation. The results allow us to validate the choice of [111] orientation for active media in the frame of high power laser systems. We then focus on ceramics because their mechanical isotropy appears to be interesting for high power systems. We study the ceramics made by wet route synthesis and highlight a strong heating, restricting their utilization. Several hypothesis are then investigated to explain this effect.In the last chapter we finished the design of the pump source with simulations of absorption, gain and energy extraction. We finally detailed the experimental results for two different architectures (regenerative and multipass), using Yb:CaF2 crystals in active mirror configuration
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Hönninger, Clemens. "Ultrafast ytterbium-doped bulk lasers and laser amplifiers /." [S.l.] : [s.n.], 1998. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=12952.
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Meshkinfam, Peyman. "Erbium-ytterbium co-dopped ion-exchanged waveguide amplifiers." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0029/MQ38696.pdf.
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Rydberg, Sara. "Radiation induced losses in Ytterbium doped laser materials." Licentiate thesis, Mittuniversitetet, Avdelningen för elektronikkonstruktion, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-18687.
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In this work, two types of ytterbium (Yb) doped laser materials are studied, crys-talline Yb:YAG and amorphous Yb/Al silica in both preform and fiber. Yb is suitableas a laser ion because of its simple energy level structure and low quantum defect.The ground and excited energy levels are separated by 10000 cm−1, but the exis-tence of another transition in the ultra violet (UV) region causes problems in a Ybdoped laser. The UV absorption band represents a charge transfer (CT) transitionwhich involves the transition of an electron from a nearby oxygen ion to the Yb ionand changes the Yb ion from trivalent to divalent with the corresponding forma-tion of a hole center. The color center formation causes a permanent optical loss inthe material in the visible to near infrared (NIR) spectral region, which absorbs thepump and laser wavelengths. The output power of the laser is reduced and this isknown as the photodarkening (PD) phenomenon.It is suggested that the excited state absorption of the Yb3+ ion is involved in thetransfer route of NIR photons to the UV range.The increase of Yb2+ upon UV irradiation is shown in both Yb:YAG and theYb/Al silca preform. The existence of Yb2+ luminescence from a photodarkenedfiber is also shown, which proves that PD occurs through a CT process.<br>I det h¨ar arbetet studeras de tv°a ytterbium-dopade lasermaterialen Yb:YAG ochYb/Al-dopat glas i form av b°ade preform och fiber. Ytterbium ¨ar l¨amplig som laser-jon p°a grund av sin enkla engerginiv°astruktur och l°aga kvantdefekt. Grundtillst°andetoch det exciterade tillst°andet ¨ar separerade med 10000 cm−1, men det finns ytterli-gare en ¨overg°ang, i UV-omr°adet, som kan skapa problem i en ytterbium-dopad laser.Denna UV-absorption inneb¨ar en laddnings¨overf¨oring (CT) fr°an en omgivande syre-jon till ytterbiumjonen och leder till en valens¨andring i ytterbiumjonen fr°an trev¨ardtill tv°av¨ard och bildandet av ett f¨argcenter. Bildandet av f¨argcenter skapar en per-manent optisk f ¨orlust i materialet, i det synliga till n¨ara infrar ¨oda omr°adet, vilket ab-sorberar pump- och laserstr°alningen. Laserns uteffekt reduceras och detta fenomen¨ar k¨ant som "photodarkening" (PD).Det f ¨oresl°as att absorption fr°an det exciterade tillst°andet i Yb3+-jonen ¨ar en bidra-gande orsak till den ¨overf¨oring av n¨ara infrar ¨oda fotoner till UV-omr°adet som sker.En ¨okning av Yb2+ vid UV-str°alning visas b°ade f ¨or Yb:YAG och f ¨or den Yb/Al-dopade glaspreformen. F¨orekomsten av Yb2+-luminescens fr°an en Yb/Al-dopadfiber som har genomg°att PD visas ocks°a, vilket bevisar att PD sker genom en CT-process.
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Wright, Fiona Cameron. "Highly polarised ytterbium doped photonic crystal fibre lasers." Thesis, University of Strathclyde, 2010. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=11869.
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Peters, Rigo [Verfasser]. "Ytterbium-dotierte Sesquioxide als hocheffiziente Lasermaterialien / Rigo Peters." Aachen : Shaker, 2009. http://d-nb.info/1159835608/34.
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Braverman, Boris. "Cavity quantum electrodynamics with ensembles of ytterbium-171." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/120364.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2018.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (pages 313-328).<br>In this thesis, I present the realization of a system applying the tools of cavity quantum electrodynamics to an atomic optical lattice clock. We design and implement a unique experimental cavity structure, with a small radius of curvature mirror on one side and a large mirror on the other side. With this structure, we are able to probe ytterbium-171 atoms in both the weak and strong coupling regimes of cavity quantum electrodynamics. This asymmetric micromirror structure simultaneously offers strong light-atom coupling, mechanical robustness, and excellent access to a large cavity volume. We develop a simple but accurate model for strong light-atom interactions in our system, which allows us to predict the performance of both cavity-assisted quantum non demolition measurements of the atomic state, and the back-action of the probing light onto the atomic state. We find theoretically, and confirm experimentally, that probing the atom-cavity system with two frequencies at the vacuum Rabi peaks of a system with strong collective light-atom coupling generates the largest possible entanglement between the probing light and the atomic state. With this scheme, we demonstrate atomic number measurements within a factor of 2 of the quantum Fisher information limit. By using the quantum back-action of the probing light on the atomic ensemble, we perform squeezing by cavity feedback. We produce states with -11±1 dB of variance squeezing and 14±1 dB of anti squeezing. Using theoretical simulations, we show that states with near-unitary squeezing offer significant advantages for improving atomic clocks compared to previous work. The ability to load large atomic ensembles in the strong coupling regime in our system offers several routes to the generation of highly entangled non-Gaussian quantum states. Such states can be produced by heralded measurements, or by global atom-atom interactions based on unitary spin squeezing. Altogether, we realize a system of unprecedented versatility and great potential for performing a large variety of hybrid atomic clock and cavity QED experiments.<br>by Boris Braverman.<br>Ph. D.
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Kusmartseva, Anna Feodorovna. "Quantum hidden order in weakly magnetic ytterbium systems." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613091.
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Freytag, Ruben. "Simultaneous magneto-optical trapping of ytterbium and caesium." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/26874.
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This thesis presents progress toward the production of ultracold CsYb molecules. To this end, an apparatus capable of producing magneto optical traps of Yb and Cs was designed, built and tested. Both atoms are produced in a dual species oven and both slowed to low speeds by a single Zeeman slower. From the Zeeman slower atoms are captured in a dual-species magneto-optical trap. To cool caesium the 852 nm D₂ transition is addressed by two lasers for cooling and repump. For ytterbium the 399 nm ¹S₀ → ¹P₁ transition is addressed for the Zeeman slower and the 556 nm ¹S₀ → ³P₁ transition is addressed for the magneto-optical trap. The 399 nm light is produced by two homebuilt diode lasers in an injection-seeding setup, which can produce up to 100 mW. The 556 nm light is produced from a commercial frequency doubled fiber laser, which can produce up to 260 mW. The Zeeman slower is characterised experimentally for both Cs and Yb, and the results compared to those of a numerical simulation of the slower for Yb. The velocity distribution exiting the slower is very sensitive to the exact magnetic field profile, the laser power and detuning of the laser light. The number of atoms loaded into the magneto-optical trap was investigated as a function of the magnetic field gradient, the laser power and the laser detuning. The capture velocity of the Yb MOT is small because the linewidth of the MOT transition is narrow, and so we investigated the influence of broadening the laser linewidth by adding multiple finely-spaced sidebands to the laser light. After optimisation the caesium MOT trapped 5.5 x 10⁸ atoms at 125 ± 4 μK. The ytterbium MOT trapped 4.7 x 10⁹ atoms at 81 ± 2 μK. Lastly we demonstrate that both MOTs can be produced in the same vacuum chamber simultaneously.
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Sugiyama, Kazuhio. "Characteristics of Ytterbium Ions Stored in RF Traps." Kyoto University, 1996. http://hdl.handle.net/2433/77847.
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Selvas-Aguilar, Romeo de Jesus. "Cladding-pumped neodymium and ytterbium doped fibre lasers." Thesis, University of Southampton, 2004. https://eprints.soton.ac.uk/41526/.
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This thesis details my work on both high-power neodymium-doped fibre lasers (at around 1.1 μm and around 0.9 μm) and ytterbium-doped fibre lasers (at 980 nm). The main subjects were the study of efficient three-level compact continuous-wave fibre lasers and their power scaling.Ytterbium-doped fibre lasers (YDFLs) with emission at 980 nm were also investigated. I, in collaboration, obtained the highest reported output power from any compact single-mode 980 nm laser to this point. For this, speciality fibres, with special core and inner-cladding designs, were developed, notably the jacketed-air-clad (JAC) fibre, with properties that are not attainable in conventional double-clad fibres. The JAC structure allows for a small pump waveguide (inner cladding) with a high NA. This is an essential advantage for lasers operating on a transition to the ground state, such as YbThere are many considerations involved with making practical, reliable, and usable 980 nm fibre devices. The integration of all required functions into a single fibre device with a small, high-NA, inner cladding is a challenge that required a large research effort to solve. A thorough and careful design and characterisation effort led to the milestone achievement of an all-fibre pigtailed fibre laser at 980 nm, which later on was used in practice as a pump source for an 8-channel DFB fibre laser transmitter array. In addition, a 980 nm Q-switched fibre laser is realised in a cladding-pumped configuration for the first time.Furthermore, a fibre laser cladding-pumped by a high brightness intra-cavity beam-combined diode was demonstrated. Here, a multi-stripe, multi-mode diode was set-up for intra-cavity beam combination and used for cladding-pumping of fibre lasers with a small inner cladding. This high-brightness pumping scheme with a multi-emitter diode appears very attractive for power scaling of three-level fibre lasers.
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Renaud, Cyril C. "High-power diode-pumped ytterbium-doped fibre-laser." Thesis, University of Southampton, 2001. https://eprints.soton.ac.uk/38210/.
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This thesis details the work I have done on double cladding ytterbium-doped fibre lasers. The two main subjects developed were the study of an efficient compact-launching system, and the operation of the double cladding compact fibre as a continuous-wave laser and a Q-switched laser.During this work, highly efficient side launching systems were developed. These allowed coupling of more than 70% of the pump light into the doped fibre and gave as good lasing efficiency as end-pumping system. The pump and the signal were also well separated in two different guides at the ends of the device. Efficient lasing at 976 nm (85% slope efficiency) was demonstrated too, by using small inner cladding area and double passed pump. Finally, pulse-energy as high as 7.7 mJ was achieved with a large core cladding pumped ytterbium doped Q-switched fibre laser.
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Wang, Jingzhou. "Spectroscopic Studies of Ytterbium Doped III-Nitride Semiconductors." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1249551044.
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Holmes, Stephen Anthony. "Organic derivatives of ytterbium and related 4f-elements." Thesis, University of Sussex, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701980.
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Fukuhara, Takeshi. "Production of Quantum Degenerate Gases of Ytterbium Atoms." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/124403.
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Scharfenberger, Benedikt [Verfasser]. "Seitenbandkühlung von gespeicherten Ytterbium-Ionen im Mikrowellenregime / Benedikt Scharfenberger." Siegen : Universitätsbibliothek der Universität Siegen, 2013. http://d-nb.info/1032394250/34.
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Palmer, Guido [Verfasser]. "Hoch-Energie Ytterbium-Laseroszillatoren mit Cavity-Dumping / Guido Palmer." Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2009. http://d-nb.info/1032725567/34.
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Sterling, Robin C. "Ytterbium ion trapping and microfabrication of ion trap arrays." Thesis, University of Sussex, 2012. http://sro.sussex.ac.uk/id/eprint/39684/.
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Over the past 15 years ion traps have demonstrated all the building blocks required of a quantum computer. Despite this success, trapping ions remains a challenging task, with the requirement for extensive laser systems and vacuum systems to perform operations on only a handful of qubits. To scale these proof of principle experiments into something that can outperform a classical computer requires an advancement in the trap technologies that will allow multiple trapping zones, junctions and utilize scalable fabrication technologies. I will discuss the construction of an ion trapping experiment, focussing on my work towards the laser stabilization and ion trap design but also covering the experimental setup as a whole. The vacuum system that I designed allows the mounting and testing of a variety of ion trap chips, with versatile optical access and a fast turn around time. I will also present the design and fabrication of a microfabricated Y junction and a 2- dimensional ion trap lattice. I achieve a suppression of barrier height and small variation of secular frequency through the Y junction, aiding to the junctions applicability to adiabatic shuttling operations. I also report the design and fabrication of a 2-D ion trap lattice. Such structures have been proposed as a means to implement quantum simulators and to my knowledge is the first microfabricated lattice trap. Electrical testing of the trap structures was undertaken to investigate the breakdown voltage of microfabricated structures with both static and radio frequency voltages. The results from these tests negate the concern over reduced rf voltage breakdown and in fact demonstrates breakdown voltages significantly above that typically required for ion trapping. This may allow ion traps to be designed to operate with higher voltages and greater ion-electrode separations, reducing anomalous heating. Lastly I present my work towards the implementation of magnetic fields gradients and microwaves on chip. This may allow coupling of the ions internal state to its motion using microwaves, thus reducing the requirements for the use of laser systems.
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Jones, Jonathan. "Quantum metrology with a single ytterbium ion optical clock." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8741/.
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The thesis focusses on the developments and measurements of the Yb+ optical clock at NPL. During my period there, new ion traps, trap control electronics and optical cavities have been developed. Numerous measurement campaigns have been conducted, where we measured the absolute frequency of both optical clock transitions in Yb+ relative to caesium, for the first time ever directly measured the frequency ratio of these transitions, and performed numerous international comparisons against other optical clocks. The total systematic uncertainty of the clock is now expected to be at the mid-low 10-18 level, with published uncertainty budgets at the mid 10-17 level, making it a strong candidate for a future redefinition of the second. The exotic electron structure of the excited levels in Yb+ make it a promising system for tests of fundamental physics. The frequencies of the transitions used in the Yb+ clock are highly sensitive to changes in the fine structure constant, α, which is predicted to vary by many physical theories beyond the standard model. By combing our absolute frequency measurements with a history of atomic clock measurements, we can place new best limits on the present day time variation of α, and the proton-electron mass ratio, µ.
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Bai, Jinxu. "High Power High Energy Ytterbium-doped Fiber Amplifier System." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/728.
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Fiber amplifiers with high power and high pulse energy are strongly in demand for both scientific research and industrial applications. Ytterbium-doped fiber has been an outstanding choice for its broad-gain bandwidth and excellent power conversion efficiencies. In this dissertation, we introduced a compact high power high pulsed energy laser system with chirally coupled core (3C) Yb-doped fibers as the gain media. Traditional standard fibers and photonic crystal fibers are not suitable for compact high power high pulse energy laser systems because of poor higher order modes (HOMs) management and complicated air-hole structure. Newly invented 3C silica fibers solve these problems. A helical side-core around the Yb-doped central core extracts the HOMs from the central core. By adjusting this chirally structure, the core of the 3C fiber can be enlarged and the transverse mode of the fiber can be single mode at certain wavelengths. To simulate the amplification process with high power high pulse energy better, a new modeling method based on a combination of the rate equations and the nonlinear Schrödinger equations is invented. The gain was calculated from rate equations and the pulse evolution was analyzed using nonlinear Schrödinger equation. The simulation provided a good guidance for building compact high power high pulse energy laser systems. To achieve high power and high pulse energy, the system is designed as a two-stage structure. The laser
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Jones, Julian Kelly. "Diffusively doped thulium- and ytterbium-lithium niobate waveguide lasers." Thesis, University of Southampton, 1995. https://eprints.soton.ac.uk/399106/.
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This thesis describes the work carried out on diffusively doped Tm - and Yb - Ti:LiNbO3 waveguide lasers. During the course of this investigation the fabrication, spectroscopy, and laser characterisation of the resulting devices was performed. Rare earth doping was accomplished using the thermal indiffusion technique, which is a highly flexible method for doping this very useful optical material. This study produced the first Yb:LiNbO3 laser, and the first room temperature Tm:LiNbO3 laser. Also the first detailed spectroscopy of Yb:LiNbO3 was performed here. Laser emission was seen in a Yb:LiNbO3 Ti waveguide at 1008, 1030 and 1060nm, with a threshold of 15mW absorbed pump power. The threshold in a Tm:LiNbO3 Ti waveguide was 17mW and lasing was seen at 1.81 and 1.853 µm. The laser potential of the 1G4 to 3H6 transition at about 470nm in Tm:LiNbO3 was also examined, using absorption spectroscopy and McCumber analysis. Photorefractivity, however, adversely affected the laser performance of these devices, and a number of methods for eliminating photorefractivity were applied for the first time to waveguide lasers. In an attempt to reduce photorefractivity a Tm:LiNbO3 Ti waveguide was successfully periodically poled using the wet electrode technique; this did not, though, eliminate photorefractive damage in the resulting device. A Tm:LiNbO3 Ti waveguide laser doped with the rare earth at above the Curie point of LiNbO3 was, however, non photorefractive, and an oxygen anneal process was also successfully used in a Yb:LiNbO3 laser. Although the majority of the work presented here was on LiNbO3, some work, however, was also carried out on the widely used laser crystal YAG (Y3Al5O12). Here a new method of waveguide fabrication in YAG was investigated, this is described at the end of this thesis.
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Shivitz, Robert William. "Techniques in laser cooling and trapping of atomic Ytterbium /." view abstract or download file of text, 2003. http://wwwlib.umi.com/cr/uoregon/fullcit?p3095274.
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Thesis (Ph. D.)--University of Oregon, 2003.<br>Typescript. Includes vita and abstract. Includes bibliographical references (leaves 235-246). Also available for download via the World Wide Web; free to University of Oregon users.
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Gomes, Diego Ribas. "Nanosecond ablation of alumina with an ytterbium fibre-laser." reponame:Repositório Institucional da UFSC, 2014. https://repositorio.ufsc.br/xmlui/handle/123456789/123313.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Programa de Pós-Graduação em Ciência e Engenharia de Materiais, Florianópolis, 2014.<br>Made available in DSpace on 2014-08-06T18:04:10Z (GMT). No. of bitstreams: 1
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Previous issue date: 2014<br>Abstract : The use of advanced ceramics has been limited by the high machining costs, with grinding and polishing accounting for 50-80% of the final product's total cost; and the inability of achieving satisfactory dimensional control and surface quality. Laser ablative processes are an alternative, considering the absence of wear-subjected tools and the possibility of very fine material removal. Although the research on laser ablation is a current topic of interest, with growing number of publications year after year, it's been focusing mainly on ultra-short pulses (in the order of pico- and femtoseconds), while the research on the low-cost and low-energy-consuming nanosecond regime (> 100 ns) is relatively scarce, specially for ceramics. This process outcomes are still difficult to predict, due to the many simultaneous and self-interacting physical processes that take place in a relatively short time. In this study, an experimental analysis has been carried out for a three-dimensional machining process with a 120 ns pulsed ytterbium fibre-laser on dense Al2O3 samples, initially through design of experiments, and later trough a step-by-step optimization procedure, evaluating ablation rate and resulting roughness. Then, surface morphology and fracture strength were evaluated for two of the "optimized" parameters sets. A very well-defined difference in removal rate and resulting surface topographies was observed, suggesting a threshold point between distinct ablation mechanisms. One of the combinations gave rise to interesting features of straight, angled shock-waves around melt pits. The fracture strength for both regimes also differed significantly, with a clear increase (121,6% e 163,5%) of the Weibull modulus combined with a decrease of the characteristic stress, compared to the non-ablated samples.
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Lesparre, Fabien. "Amplificateurs impulsionnels à base de fibres cristallines dopées Ytterbium." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLO001/document.
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Les lasers à impulsions ultra-courtes (< 10 ps) ont largement démontré leur intérêt pour de nombreuses applications scientifiques, industrielles ou encore médicales. Le domaine du micro-usinage par impulsions laser est l'un des domaines les plus actifs du moment. Les dernières avancées en la matière privilégient deux axes de recherche, l'augmentation du taux de répétition associé à de fortes puissances moyennes et une montée en énergie. Nos travaux s'inscrivent dans ce contexte et visent à développer des amplificateurs d'impulsions ultracourtes innovants à base de fibres cristallines Yb:YAG délivrant de fortes puissances moyennes et de fortes énergies en régime de polarisation cylindrique. Les sources développées sont destinées à être intégrées au sein de systèmes de micro-usinage laser aux performances inédites développés dans le cadre du projet européen Razipol. Celles-ci joueront le rôle de préamplificateur fort gain au sein d'une architecture MOPA composé d'un oscillateur ultra-rapide à base de cristal d'Yb:KYW et d'un amplificateur final à base de disque mince Yb:YAG. Pour répondre à la problématique des dégradations spatiales liées à la montée en puissance moyenne dans les architectures à laser solide pompé par diode, une architecture en cascade composée de trois étages d'amplification permettant de réduire la charge thermique a d'abord été réalisée. Grâce à une fine optimisation de l’ensemble des paramètres spectroscopiques (taux de dopage des cristaux, longueur d'onde de pompe...) et géométriques (longueur des cristaux, tailles de faisceaux...) a permis d'amplifier des impulsions femtosecondes (750 fs) jusqu'à des puissances moyennes de 100 et 85 W, respectivement obtenues en polarisation linéaire et cylindrique, à la cadence de 20 MHz. Un amplificateur picoseconde de forte énergie à également été réalisé. Intégrant un dispositif de combinaison cohérente à division temporelle à 4 ou 8 répliques visant à réduire les effets non-linéaires, la source développée délivre des énergies remarquablement élevées pour ce type de système à amplification directe. Il délivre des énergies de 1 et 2 mJ à des cadences inférieures à 20 kHz. Ces résultats ont fait l'objet de 2 publications dans des revues internationales à comité de lecture. Par ailleurs les deux amplificateurs développés ont été intégrés sous la forme de systèmes compactes et robustes, utilisables par les membres du projet européen Razipol. Ces travaux ont également inspirée une nouvelle ligne de produits désormais commercialisés la société Fibercryst<br>In the last decade ultra-short pulse laser (< 10 ps) have sparked increasing interest for many industrial and scientific applications. Among the geometries used so far for high-power Yb-doped diode-pumped solid-state lasers as slabs, rods and thin disks, the single crystal fiber (SCF) technology was recently shown to have a high potential for the amplification of ultrashort pulses thanks to a very efficient thermal management and high optical efficiencies. This technology combined with the cubic crystal structure of Yb:YAG offers a cylindrical symmetry of the optical and thermo-mechanical properties. Yb:YAG SCFs are therefore well suited for the amplification of cylindrically polarized beams. In the context of a European Project called RAZIPOL, we have developed new laser amplifier architectures using SCF to directly amplify femtosecond pulses to achieve high energy and high average power pulses with radial and azimuthal polarizations without any stretching and recompression of the pulses.We first demonstrate a three-stage diode-pumped Yb:YAG single-crystal-fiber amplifier to generate femtosecond pulses at high average powers with linear or cylindrical (i.e., radial or azimuthal) polarization. At a repetition rate of 20 MHz, 750 fs pulses were obtained at an average power of 85 W in cylindrical polarization and at 100 W in linear polarization. Investigations on the use of Yb:YAG single-crystal fibers with different length/doping ratios and the zero-phonon pumping at a wavelength of 969 nm were conducted in order to optimize the performances of the amplifiers.The second part of the project is focused on pulse energy scaling. In this sense, we demonstrate a two-stage Yb:YAG single-crystal-fiber amplifier designed for high peak power to significantly increase the pulse energy of a low power picosecond laser. The first amplifier stage has been designed for high gain. Using a gain medium optimized in terms of doping concentration and length an optical gain of 32dB has been demonstrated. The second amplifier stage designed for high energy using divided pulse technique allows to generate recombined output pulse energy of 2mJ at 12.5 kHz with a pulse duration of 6 ps corresponding to a peak power 320MW. Average powers ranging from 25W to 55W with repetition rates varying from 12.5 kHz to 500 kHz have been demonstrated.This results has led to the publication of 2 articles in international peer-reviewed journals and have been presented in 7 conferences. Finally this work has inspired the launch of a new line of industrial products by Fibercryst
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Tegomo, Chiogo Bodry. "Spectroscopic studies of cerium and Ytterbium-based Kondo systems." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0193.
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Les composés de cérium et d'ytterbium sont des systèmes qui présentent des propriétés magnétiques, électroniques et thermodynamiques exceptionnelles à basse température, tels que l'effet Kondo, les fermions lourds, la valence intermédiaire et des ondes de densité de charge. Ces propriétés sont dues aux interactions électron-électron très fortes des états f et à l'hybridation des états f avec les électrons de conduction. Dans la première partie de ce travail de thèse, nous étudions la structure électronique de l'YbPd, un composé cubique à haute température, qui présente des ondes de densité de charge (CDW) incommensurable et commensurable dans en dessous de T_1 = 130 K et T_2 = 105 K, respectivement. En dessous de 105 K, les sites magnétique Yb^{3+} et non magnétique Yb^{2.6+} sont disposés alternativement le long de l'axe c, en une structure tétragonale présentant un ordre de valence. La spectroscopie de photoémission de rayons X durs (HAXPES) des états 3d de l'Yb montre des caractéristiques Yb^{2+} et Yb^{3+} indépendantes de la température au-dessus de T_1, et un changement de valence des deux sites cristallographiques d'Yb dans la phase CDW. Des calculs des spectres HAXPES au seuil 3d de l'Yb avec un modèle à une impureté d'Anderson simplifié montrent un bon accord avec la dépendance en température de la valence et fournissent les températures de Kondo des deux sites d'Yb. Les résultats indiquent une évolution de la valence intermédiaire dans la phase cubique à un ordre CDW statique à longue portée dans la phase tétragonale. Nous proposons que le mécanisme Kondo est à l'origine de l'onde de densité de charge. La diffusion inélastique résonante des rayons X est une technique très efficace pour étudier les excitations élémentaire dans une large variété de systèmes tels que les excitations de transfert de charge, les excitations de champ cristallin et de spin-orbite. Dans la deuxième partie de ce travail, le RIXS combiné avec des simulations à base du modèle à une impureté d'Anderson et la théorie des multiplets a été utilisé pour l'étude des composés de cérium avec différentes températures de Kondo T_K. Nous avons démontré que toutes les excitations de charge observées en les spectres de photoémission et photoémission inverse combinés peuvent être mises en évidence par la spectroscopie RIXS simplement en faisant varier l'énergie du photon incident autour du seuil M_5 du cérium. Nous discutons également de la dépendance drastique de la structure f^0 dans les spectres RIXS en fonction de la polarisation et de la forte dépendance en température de la structure de type fluorescence, qui rappelle la dépendance à la température de la résonance de Kondo<br>Cerium and ytterbium compounds are systems that exhibit outstanding magnetic, electronic, and thermodynamic properties at low temperatures, such as the Kondo effect, heavy fermions, intermediate valence, and charge density waves. These properties are due to the very strong electron-electron interactions of the f states and the hybridization of the f states with the conduction electrons. In the first part of this thesis work, we investigate the temperature-dependent electronic structure of YbPd, a Kondo mixed-valent cubic compound at high temperature, which exhibits incommensurate and commensurate charge-density-wave (CDW) ordering below T_1 = 130 K and T_2 = 105 K, respectively. Below 105 K, magnetic Yb^{3+} and nonmagnetic Yb^{2.6+} are arranged alternatively along the c axis, in a tetragonal structure exhibiting valence order. Hard x-ray photoemission spectroscopy of Yb 3d states show temperature-independent Yb^{2+} and Yb^{3+} features indicating single-Yb site dynamic valence fluctuations above T_1, and a clear temperature dependent valence change of the two crystallographic Yb sites in the CDW phase. Simplified single-impurity Anderson model calculations of the Yb 3d states show good agreement with the temperature-dependent valency change and provide site-dependent Kondo temperatures. The results indicate an evolution from dynamic mixed-valence in the cubic phase to long-range static CDW order in the tetragonal phase, which is driven by the difference in Kondo energies of the two phases. Resonant inelastic x-ray scattering (RIXS) is a very efficient technique to study elementary excitations in a large variety of systems, such as charge transfer excitations, the crystal field, and spin-orbit excitations. In the second part of this work, we investigated cerium compounds with different Kondo temperatures using RIXS at Ce M_5-edge combined with simulation using the full multiplet theory and the single impurity Anderson model. We demonstrated that all the charge excitations observed in combined photoemission and inverse photoemission can be evidenced by RIXS spectroscopy just by varying the incident photon energy around the Ce M_5-edge. We also discuss the drastic polarization dependence of the f^0 structure in RIXS spectra and the strong temperature dependence of the fluorescence-like structure, which is reminiscent of the temperature dependence of the Kondo resonance
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Chavoutier, Marie. "Cristallogenèse, caractérisation spectroscopique et potentialité laser de borates et d’oxyborates de terre rare dopés ytterbium." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14091/document.
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Facilement excitable au moyen de diode InGaAs, l’ion Ytterbium trivalent présenteune émission infrarouge intéressante pour des applications laser. Les matériaux étudiés sontnombreux. Parmi eux, les borates sont des composés stables, transparents dans l’UV et présentant un seuil élevé au dommage. Ils sont par conséquent des bons candidats pour desapplications optiques. D’un point de vue structural, ils présentent une diversité de sitesd’accueil pour la terre rare ce qui permet de moduler les émissions obtenues en fonction de lacomposition.Nous avons mené une étude d’élaboration et de caractérisation sur un borate (à fusioncongruente) et deux oxyborates (à fusion non congruente) de composition : Li6Ln(BO3)3 ;LiGd6O5(BO3)3 ; Na3La9O3(BO3)8.Les différentes croissances cristallines, par la méthode Czochralski ou par la méthodedu flux, nous ont permis d’obtenir des cristaux de taille centimétrique comportant de largeszones transparentes, utiles pour les tests en cavité laser. L’étude spectroscopique de l’ionytterbium nous a permis d’évaluer l’éclatement des niveaux d’énergie et de localiser les ionsterres rares dans ces matrices. Différentes caractérisations thermiques, mécaniques et optiquesont aussi été réalisées sur les cristaux afin de pouvoir estimer les paramètres laser.Finalement, de premiers tests lasers ont été réalisés et ont montré la potentialité de cesmatériaux en tant que matériaux amplificateurs<br>By the mean of InGaAs diode, trivalent ytterbium ions can give rise to an interestinginfrared emission for laser applications. Numerous compounds are in study. Among them,borates are stable, UV-transparent compounds and they have a high damage threshold. Thusthey are good candidates for optical applications. From a structural point of view, they exhibita diversity of host sites for the rare earth which allows to modulate emission withcomposition.We carry out an elaboration and characterization study on a borate and two oxyboratecompounds of formula Li6Ln(BO3)3 ; LiGd6O5(BO3)3 ; Na3La9O3(BO3)8.Crystal growth, by Czochralski or flux method depending on the meltingcharacteristic, enable us to obtain centimetric sized crystals with large transparent areas.Ytterbium ion spectroscopy study enables us to estimate energy levels splitting and to locaterare earth ions in these matrices. Several thermal, mechanical and optical characterizations were also performed on the crystals to estimate laser parameters. Finally, first laser tests werecarried out and have shown the potentiality of these materials as amplifier media
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Zuliani, Alexandre. "Vers la manipulation optique d'atomes ultra-froids d'ytterbium excités dans des états de Rydberg." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS141/document.
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Les propriétés exacerbées des atomes de Rydberg ont permis d'étendre les possibilités offertes par les atomes froids dans la création de gaz d'atomes en très forte interaction, avec des applications notamment en simulations quantiques, dans la physique à N corps ou dans la réalisation de portes quantiques grâce au phénomène de blocage dipolaire. L'utilisation des atomes de Rydberg froids est cependant actuellement limitée par le fait qu'il n'est pas possible de continuer d'appliquer les techniques expérimentales de manipulation optique avec les atomes à un électron actif. L’attention de la communauté des atomes de Rydberg froids s’est donc récemment portée sur les atomes à deux électrons actifs qui offrent la possibilités, une fois l’un des deux électrons excité vers un état de Rydberg, de disposer d’un second électron optiquement actif qu’il va être possible de manipuler par laser. L’objectif de cette thèse est d’étendre les techniques de manipulation optique aux atomes à deux électrons actifs excités dans des états de Rydberg, dans le cas de l’atome d’ytterbium. Elle présente d’une part la conception et l’assemblage du dispositif expérimental permettant l’obtention d’une source d’atomes de Rydberg froids d’ytterbium. A terme, ce montage permettra la manipulation optique de ces atomes de Rydberg. D’autre part, elle présente le développement d’un modèle numérique implémentant la théorie du défaut quantique à plusieurs voies pour permettre la détermination théorique du spectre énergétique de l’ytterbium ainsi que son comportement sous l’effet de perturbations extérieures<br>The exacerbated properties of Rydberg atoms have extended the possibilities offered by cold atoms in creating atomic gases in very strong interaction with applications including quantum simulations in many-body physics or in achieving of quantum gates with the dipole blocking phenomenon. The use of cold Rydberg atoms is however currently limited by the fact that it is not possible to continue to apply the experimental techniques of optical manipulation with the atoms to an active electron. The attention of the Rydberg atoms cold community is recently focused on the two active electron atoms offering possibilities, once one of the two electrons excited to a Rydberg state, to provide a second optically active electron that it will be possible to manipulate with laser light.The objective of this thesis is to extend the optical manipulation techniques to atoms with two active electrons excited in Rydberg states, in the case of the ytterbium atom. It has on the one hand the design and assembly of the experimental apparatus for obtaining a source of cold Rydberg ytterbium atoms. Ultimately, this device will allow the optical manipulation of these Rydberg atoms. Furthermore, it presents the development of a numerical model that implements the multichannel quantum defect theory to the theoretical determination of the energy spectrum of ytterbium and its behavior under the influence of external perturbations
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Casanova, Alexis. "Caractérisation et réduction de la gigue temporelle de lasers ytterbium ultrabrefs pompés par diode." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0931.
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Ce travail de thèse se concentre sur la caractérisation et la correction de la gigue temporelle de lasers ultrabrefs, c'est-à-dire avec une durée d'impulsion sub-picoseconde, pompés par diode et avec un milieu à gain dopé à l'Ytterbium. Ce type de source laser a bénéficié d'un développement industriel rapide depuis le début des années 2000 et a trouvé de très nombreuses applications, notamment dans le domaine scientifique pour des expériences résolues en temps (FELs, accélérateurs de particules, OPAs...). Dans ce type d’applications, la réduction de la gigue des impulsions permet d’accéder à de meilleures résolutions temporelles et permet d’observer des phénomènes physiques extrêmement brefs.Dans ce travail, la gigue d'oscillateurs lasers ultrabrefs à verrouillage de mode passif a été corrigée et caractérisée en générant un signal d'erreur par photo-détection directe d'une part et par corrélation croisée optique d'autre part. La correction de la gigue temporelle par corrélation croisée optique permet d'obtenir une gigue résiduelle inférieure à 5fs, de l'ordre de la durée d'un cycle optique, avec des oscillateurs compacts et industriels. Une gigue résiduelle de ce niveau permet d’accéder à des expériences résolues en temps exigeantes en termes de stabilités temporelles des sources de lumière utilisée, par exemple une expérience d’interaction lumière-matière de type pompe-sonde avec une source laser à électrons libres.Un nouvel instrument basé sur la corrélation statistique des signaux de gigue générés par deux canaux de corrélations croisées optiques a été mis en place. Un tel instrument a permis de caractériser complètement la gigue temporelle d'oscillateurs à des fréquences de Fourier supérieures à la dizaine de kiloHertz lasers ultrabref en atteignant un plancher de bruit sub-zeptoseconde. La gigue additive d'amplificateurs lasers ultrabrefs a également été caractérisée par corrélation croisée optique, cela afin d'acquérir une compréhension globale de la gigue introduite par une chaîne laser ultrabrève amplifiée.Les mesures effectuées ont permis d’analyser les origines physiques de la gigue dans un système laser ultrabref. Ces résultats permettront à terme d’améliorer la correction de la gigue sur les systèmes industriels étudiés ainsi que de développer de nouvelles sources laser ultrabrèves intrinsèquement moins bruyantes. Une telle étude expérimentale pourra également servir de support pour éventuellement enrichir le modèle théorique des perturbations dans un laser ultrabref<br>The main scope of this PhD work is to characterize and reduce the timing jitter of optical pulses with sub-picosecond duration, emitted by diode-pumped ultrafsat lasers with Ytterbium doped gain media. Such laser sources have been rapidly enhanced by a high-grade and efficient industrial development, giving access to numerous novel applications, especially in the fields of applied physics and chemistry with time-resolved experiments based on interaction between light and matter. In this latter topic resides a constant need to minimize the laser pulse train timing jitter in order to access physical phenomena with extremely short timescales such as electrons recombination.Two main detection techniques have been studied to characterize the timing jitter from passively modelocked laser oscillators. The first technique is based on direct photo-detection in the microwave domain whilst the second technique makes use of the balanced optical cross-correlation. Residual timing jitter from industrial compact laser oscillators has been reduced below 5fs, close to an optical cycle period. This performance makes the laser oscillators produced by Amplitude-Systemes already suitable for challenging time-resolved pump-probe experiments, in the presence for example of a free electron laser source.Timing jitter analysis has been enhanced by studying the cross-spectrum from jitter signals generated from two balanced optical cross-correlators. This technique allowed the entire characterization of the timing jitter density spectrum from laser oscillators above the ten-kiloHertz Fourier frequency with a sub-zeptosecond noise floor. Additive timing jitter from ultrafast laser amplifiers has also been studied with optical cross-correlation and gives a global comprehension of the timing jitter from a complete high-energy ultrafast laser chain.The collected measurments will be conducive to design a more adapted and performant timing synchronization system for industrial laser sources. A better knowledge of the non-trivial jitter sources, dependent on the laser parameters, will also allow to design intrinsically low-noise new laser sources based on the Ytterbium gain media. The cross-spectrum technique developed could be of use to characterize other laser technologies and to investigate the theoretical perturbation model of ultrafast lasers with a better experimental insight
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Mouzon, Johanne. "Synthesis of ytterbium-doped yttrium oxide nanoparticles and transparent ceramics." Doctoral thesis, Luleå : Division of Engineering Materials, Luleå University of Technology, 2006. http://epubl.ltu.se/1402-1544/2006/64/.
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Shankar, Ratnambikai. "Erbium/Ytterbium co-doped planar waveguide amplifiers, modeling and fabrication." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ60495.pdf.
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Diniz, Vivian. "Biosorption of lanthanum, europium and ytterbium by Sargassum polycystum biomass." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111841.
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Biosorption of the lanthanides: La3+ (Lanthanum), EU 3+ (Europium) and Yb3+ (Ytterbium) from single and multi-component batch and column systems using Sargassum polycystum biomass was studied. Ground and dried biomass was used in batch experiments with particle size 0.5-2.0 mm, while natural size cut and wet was used for packing the column. The ion exchange mechanism was confirmed by the exchange of ions observed during the process. The metal binding increased with pH and the maximum metal uptake capacity for pH 3, 4 and 5 ranged approximately between (0.8--0.9) mmol.g-1 for La, (0.8--0.9) mmol.g -1 for Eu, and (0.7--0.9) mmol.g-1 for Yb. The metal affinity sequence established was Eu>La>Yb, and the maximum metal uptakes obtained from multi-metal mixture were 0.41, 0.29, and 0.28 mmol.g -1 for Eu, La, and Yb, respectively. The presence of the rounterion sulphate reduced La uptake due to the formation of complexes, while the presence of nitrate and chloride did not interfere with the lanthanum removal. The La uptake in such systems varied from 0.6 to 1.0 mmol g-1. Several eluting agents at different concentrations were tested to desorb the lanthanides and 95 to 100% desorption for all metals was obtained with 0.3 mol.L-1 HCl. La desorption with the other eluting agents was 70% with 2 mol.L-1 CaCl2, 83.7%, with 0.5 mol.L -1 EDTA and 88.4% with 0.023 mol.L-1 diglycolic acid. Desorption levels ranged between 85 and 95%, and decreased with increasing metal sorption affinity as follows, 94.0, 86.3 and 75.2% for Yb, La and Eu, respectively, when the eluting agent was 0.1N HCl. Batch and sorption column studies of La and Eu in the presence of protons in binary and ternary systems were performed. The equilibrium isotherms were determined for the binary systems, La/H and Eu/H, for a total normality of 3meq g-1, and resulted in separation factors of 2.7 and 4.7, respectively, demonstrating a higher selectivity of the biomass towards europium. Continuous-flow column experiments with single metals and protonated biomass were used to estimate the intra-particle mass transfer coefficient for La (6.0 10-4 min-1 and Eu (3.7 10-4 min-1). These values were then used in mathematical models predicting reasonably well the breakthrough curves obtained for La and Eu with an equivalent feed mixture. A series of consecutive sorption/desorption runs demonstrated that the metal could be recovered and the biomass reused in multiple cycles with no apparent loss in metal uptake capacity when 0.1N HCl was used for desorption.
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Kara, Dhiren Manji. "Toward an electron electric diploe moment measurement using Ytterbium fluoride." Thesis, Imperial College London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.536009.
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Wood, Mark. "Combined radiative and collisional effects in the spectrum of ytterbium." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295510.
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Bland, S. W. "A study of ytterbium and europium in the alkali halides." Thesis, University of Warwick, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373073.
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