Tesis sobre el tema "Optical atomic clocks"
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Dovale, Alvarez Miguel. "Optical cavities for optical atomic clocks, atom interferometry and gravitational-wave detection". Thesis, University of Birmingham, 2019. http://etheses.bham.ac.uk//id/eprint/8851/.
Texto completoLytle, Christian y Christian Lytle. "Spectroscopy of Neutral Mercury in a Magneto-Optical Trap Based on a Novel Ytterbium Fiber-Amplified Cooling Laser Source". Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/621471.
Texto completoSchulte, Marius [Verfasser]. "Entanglement in Ramsey interferometry, optical atomic clocks and trapped ions / Marius Schulte". Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2020. http://d-nb.info/1226286194/34.
Texto completoLamilla, Rubio Erick Abraham 1985. "Transmitindo padrões de frequência atômicos por redes de fibras ópticas=Transmitting atomic frequency standards in optical fiber networks". [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/276939.
Texto completoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
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Resumo: Neste trabalho foi feito um estudo experimental da transmissão de padrões de frequência atómicos através de uma rede de fibra optica. Até onde sabemos este tipo de transmissão foi realizada pela primeira vez no Brasil. Utilizamos uma conexão de fibra óptica entre o Instituto de Física Gleb Wataghin (IFGW) e a Faculdade de Engenharia Elétrica e Computação (FEEC) da UNICAMP, correspondendo a uma distância de aproximadamente 2 km, e um comprimento total de fibra de 18 km. Frequências de RF derivadas de padrões de frequência de Rubídio e de um receptor GPS foram transmitidas e caracterizadas através de medidas de frequência, particularmente por gráficos de variância de Allan, e medidas da fase
Abstract: In this experimental work, transmission of an atomic frequency standard through an optical fiber network has been implemented for first time in Brazil, to the best of our knowledge. We have used a fiber link between the Institute of Physics (IFGW) and the Department of Electrical Engineering inside the campus of the University of Campinas (UNICAMP) corresponding to 18 km fiber link (2km between buildings). Radio frequencies derived from a Rubidium standard and a GPS (Global Position system) receiver has been transmitted and characterized via phase and frequency measurements, particularly trough Allan deviation plots and phase measurements
Mestrado
Física
Mestre em Física
2013/15492-2
FAPESP
Bridge, Elizabeth Michelle. "Towards a strontium optical lattice clock". Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:a96e73fe-f17b-4738-be1d-34429b5b4a05.
Texto completoKing, Steven Anthony. "Sub-hertz optical frequency metrology using a single ion of 171Yb+". Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:428b1f40-3b5d-475e-aebc-c062b987e3f2.
Texto completoPetersen, Michael. "Laser-cooling of Neutral Mercury and Laser-spectroscopy of the 1S0-3P0 optical clock transition". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2009. http://tel.archives-ouvertes.fr/tel-00405200.
Texto completoMaximo, Carlos Eduardo. "Collective scattering of light from disordered atomic clouds". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-28022018-142502/.
Texto completoNesta tese, investigamos o espalhamento coerente de luz por átomos distribuídos aleatoriamente no espaço. Conforme descrito por um modelo de dipolos acoplados, a cooperação no processo de emissão espontânea resulta de interações puramente ópticas entre os graus internos de liberdade dos átomos. No regime opticamente diluído, onde o meio atômico pode ser descrito por um índice de refração, mostramos que a luz pode ser desviada com a aplicação de um gradiente de campo magnético. No regime denso, as interações de curto alcance parecem suprimir a localização de Anderson da luz mesmo em duas dimensões, resultado que desmonta a crença comum de que todas as ondas estão localizadas em duas dimensões. Também descobrimos que o padrão de franjas, resultante da interferência entre a luz espalhada por uma nuvem atômica e a de sua imagem especular, é robusto tanto contra a média em disordem quanto contra saturação. Finalmente, demonstramos estados ligados de dois átomos no movimento bidimensional através do acoplamento óptico de longo alcance. Este optical binding effect com um par de átomos será importante para investigar a estabilização totalmente óptica de nuvens extensas.
Abdel, Hafiz Moustafa. "Development and metrological characterization of a high-performance Cs cell atomic clock based on coherent population trapping". Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCD035/document.
Texto completoThis thesis work, performed in the frame of the MClocks European project (http://www.inrim.it/mclocks), reports the development and metrological characterization of a high-performance Cs vapor cell atomic clock based on coherent population trapping (CPT). The clock uses an optimized CPT pumping scheme, named push-pull optical pumping (PPOP), allowing the detection of high-contrast CPT resonances on the 0-0 magnetic-field insensitive clock transition. A detailed characterization of key components of the clock is reported. The clock was operated in the continuous-wave (CW) regime and in a Ramsey-like pulsed regime. In both regimes, the clock demonstrates a short-term fractional frequency stability at the level of 2 10−13 τ−1/2 up to 100 s averaging time, mainly limited by laser power effects. This CPT clock, ranking among the best microwave vapor cell atomic frequency standards, could find applications in telecommunication, instrumentation, defense or satellite-based navigation systems.This thesis reports also a novel laser frequency stabilization technique using dual-frequency sub-Doppler spectroscopy in a vapor cell. The clock ”platform” has also been used to perform using CPT spectroscopy the characterization of a Cs vapor cell coated with octadecyltrichlorosilane (OTS) or original buffer-gas filled Cs vapor micro-fabricated cells developed in FEMTO-ST for CPT-based miniature atomic clocks
Bilicki, Sławomir. "Horloges à réseau optique au strontium : comparaisons d'horloges pour des applications en physique fondamentale et échelles de temps". Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066247/document.
Texto completoThis thesis describes the latest progresses regarding the Sr optical lattice clocks at LNE-SYRTE, Observatoire de Paris. Nowadays, the systematic uncertainty and stability of optical clocks are 2 orders of magnitude better than cesium microwave fountains currently realizing the SI second, with applications in fundamental physics, astronomy and geoscience. In the near future, a re-definition of the SI second is expected, once optical clocks are proven to be as reliable and reproducible as their microwave counterparts. The thesis presents three decisive steps in this direction. First, we demonstrate nearly continuous Sr clocks over several weeks. Second, local and remote frequency comparisons against various microwave and optical frequency standards show that OLCs are reproducible over time, and by independent laboratories. We notably demonstrated the first all-optical agreement between optical clocks at continental scale. Third, the Sr clocks were used to calibrate the Temps Atomique International (TAI). The five calibration reports, which we produced, were validated by the BIPM, as the first contribution to TAI with optical clocks. In addition, some of these results were used to improve bounds on a putative violation of the Lorentz invariance by testing the stability of the frequency ratio between remote clocks. Finally, we conducted a full characterization of the frequency shifts associated with semi-conductor laser sources for the trapping light, including optical measurements and frequency shifts measurements, with applications for transportable and space clocks
Favier, Maxime. "Horloge à réseau optique de mercure : spectroscopie haute-résolution et comparaison d'étalons de fréquence ultra-précis". Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066598/document.
Texto completoThis thesis presents the development of a high-accuracy optical frequency standard based on neutral mercury 199Hg atoms trapped in an optical lattice.I will present the experimental setup and the improvements that were made during this thesis, which have allowed us to perform spectroscopy on the doubly forbidden 1S0 - 3P0 mercury clock transition with Hz level resolution. With such a resolution, we have been able to conduct an in-depth study of the physical effects affecting the clock transition. This study represents a factor 60 in accuracy on the knowledge of the clock transitions frequency, pushing the accuracy below the current realization of the si second by the best cesium atomic fountains. Finally, i will present the results of several comparison campaigns between the mercury clock and other state-of-the-art frequency standards, both in the optical and in the microwave domain
Mandt, Stephan [Verfasser], Achim Akademischer Betreuer] Rosch, Alexander [Akademischer Betreuer] [Altland y Ralf [Akademischer Betreuer] Schützhold. "Transport and Non-Equilibrium Dynamics in Optical Lattices : From Expanding Atomic Clouds to Negative Absolute Temperatures / Stephan Mandt. Gutachter: Achim Rosch ; Alexander Altland ; Ralf Schützhold". Köln : Universitäts- und Stadtbibliothek Köln, 2012. http://d-nb.info/1038227941/34.
Texto completoMandt, Stephan Verfasser], Achim [Akademischer Betreuer] Rosch, Alexander [Akademischer Betreuer] [Altland y Ralf [Akademischer Betreuer] Schützhold. "Transport and Non-Equilibrium Dynamics in Optical Lattices : From Expanding Atomic Clouds to Negative Absolute Temperatures / Stephan Mandt. Gutachter: Achim Rosch ; Alexander Altland ; Ralf Schützhold". Köln : Universitäts- und Stadtbibliothek Köln, 2012. http://d-nb.info/1038227941/34.
Texto completoNuñez, Portela Mayerlin. "Desenvolvimento de um laser de Nd:YLF bombeado por diodo laser e duplicado em freqüência para 657 nm". [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/277713.
Texto completoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
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Resumo: Os relógios atômicos são usados na atualidade em um grande número de aplicações científicas e tecnológicas que vão desde experimentos de relatividade e determinação de constantes fundamentais, até sistema de navegação (GPS) e telecomunicações. A proxima geração de relógios atômicos de alta precisão estará baseada em transições ópticas de átomos frios. Neste trabalho foi desenvolvido um laser de estado sólido de Nd:YLF bombeado por um laser de diodo e duplicado em frequência em 657 nm. Este sistema é proposto como oscilador local em um relógio atômico óptico baseado em átomos de cálcio. Comparado com os lasers de diodo, este apresenta uma potência maior no vermelho, um ruído de frequência e amplitude menores e a possibilidade de transferência remota usando obras ópticas no comprimento de onda fundamental de 1314 nm. Duplicação em frequência intra-cavidade é feita usando um cristal de BiBO, com superfícies anti-refletoras, e com um casamento de fase crítico tipo I à temperatura ambiente. Uma potência de 270 mW na saída do vermelho foi obtida para uma potência de bombeamento de 11.6 W.
Abstract: Atomic clocks are used today in a number of scientific and technological applications, ranging from tests of relativity, or variations of fundamental constants, to the use in navigation and telecommunication. The next generation of such high precision devices will be based on optical transitions of suitable laser cooled and trapped atoms. In this work we describe a frequency-doubled, diode-pumped solid-state Nd:YLF ring laser emitting at 657 nm, proposed as a local oscillator in an optical atomic clock based on laser cooled and trapped calcium atoms. Compared to diode lasers, its main advantages include higher power, less intrinsic frequency noise, and the possibility of remote transfer in optical fibers using the fundamental light at 1314 nm. Frequency doubling is performed inside the cavity using a 10 mm long AR-coated BiBO crystal, under type I, critical phase-matching at room temperature. Red output power of 270 mW was achieved for 11.6 W of pumping power.
Mestrado
Física Atômica e Molecular
Mestre em Física
Bourgain, Ronan. "Diffusion de la lumière dans les nuages denses mésoscopiques d'atomes froids". Phd thesis, Palaiseau, Institut d'optique théorique et appliquée, 2014. http://tel.archives-ouvertes.fr/tel-00978177.
Texto completoRadnaev, Alexander G. "Towards quantum telecommunication and a Thorium nuclear clock". Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/50120.
Texto completoCambier, Valentin. "Horloge à réseau optique à atomes de mercure exploitant un 2D-MOT : durée de vie de l'état 3P0 et mesures de fréquence". Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS512.
Texto completoOptical clocks have changed time and frequency metrology since the beginning of the 2000’s. In my thesis, I worked on a mercury optical lattice clock. Mercury is a promising candidate for optical clocks thanks to its weak sensitivity to blackbody radiation shift. During my PhD, I took benefit of a magneto optical trap in two dimensions (2D-MOT) to pre-cool the mercury atoms before the interrogation phase. It allows us not only to trap much more atoms but also to improve the clock cycle by decreasing the total cycle time. These improvements made possible the lifetime measurement of the 3P0 state and to participate to measurement campaigns at the European scale between different clocks located a few hundreds of kilometres apart. As a consequence, it was possible to measure for the first time the frequency ratio between mercury and Yb+ ion
Gredat, Grégory. "Propriétés de bruit et dynamique de lasers à semiconducteurs en régime d'émission bifréquence pour l'optique micro-ondes et la métrologie". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS109.
Texto completoCoherent emission of two optical tones with a radiofrequency (RF) tunable beatnote can spur many microwave photonics applications. Indeed, it can be useful for radars, remote sensing, or in the metrological context of ultra-stable RF frequency standards. A birefringent crystal can be inserted inside the external cavity of a VECSEL (vertical-external-cavity surface-emitting lasers) to produce a tunable very low-noise RF beatnote out of two orthogonal linear polarizations. Such dual-frequency semiconductor lasers operating along the D₂ line of cesium have been developed for CPT (coherent population trapping) atomic clocks. The development of these clocks corresponds to a need to find a trade-off between size and performance. First, intensity and RF beatnote phase noise investigations in these dual-frequency VECSELs are reported. A model based on coupled rate equations allows us to find minimization strategies for the noise transfer from the pump to the laser thanks to a new pumping architecture, which produces two correlated pump spots to feed the laser modes. The laser dynamics is then optimized for efficient noise active suppression. We predict a contribution to the short term relative frequency stability of the CPT clock compatible with an Allan deviation of 5x10⁻¹³ at 1s. Pump induced thermo-optic effects are dominating the low-frequency part of the dual-frequency VECSEL beatnote phase noise spectrum and require to be better understood. A new thermal model is thus established. This model takes into account the details of the gain medium, heat diffusion spatial anisotropy, thermal lens effects and also thermodynamic fluctuations. Besides, an analysis of the spectral intensity noise covariance matrix is initiated. We evidence that the eigen modes of the cross-polarized intensity fluctuations are close to in-phase and anti-phase noise mechanisms. Eventually, we elaborate a novel characterization and ranking method for non-stationary noises, which are often related to low-frequency spurious peaks
Piotrowski, Marcin. "Zastosowanie metrologiczne zimnych atomów pułapkowanych optycznie". Praca doktorska, 2015. https://ruj.uj.edu.pl/xmlui/handle/item/48897.
Texto completoTwo experiments with laser-cooled atoms held in an optical dipole traps are described in the dissertation. First is dedicated to non-linear magneto-optical effects in rubidium atoms, while second is devoted to optical lattice trap for strontium atoms. Selected metrological applications of optically trapped cold atoms in both experiments are discussed and presented. A dipole trap setup has been built at the Department of Photonics in Jagiellonian University. It is aimed at investigations of nonlinear magneto-optical effects like precise magnetometry by Faraday effect. A compact two-dimensional magneto optical (2D-MOT) trap with permanent magnets serves as a source of cold rubidium atoms for further cooling in three-dimensional magneto-optical trap (3D-MOT). The 2D-MOT is described and characterised. The results of the loading an optical dipole trap (ODT) from a the 3D-MOT are then presented. It is followed by the results of a Faraday rotation of a resonant laser beam with atoms confined in the final stage of confinement in ODT. The strontium lattice experiment is a part of a larger project: the construction of the first polish optical atomic clock (project Polish Optical Atomic Clock) at the National Laboratory for Atomic, Molecular and Optical Physics. An introduction to time and frequency metrology with optical clocks is given. We describe strontium atoms confined in the optical lattice as a frequency reference for the optical clock in detail. The results of precision spectroscopy of ultra- narrow clock transition in bosonic Sr-88 and the measurements of the clock stability based on atomic reference are presented and discussed.