Готові списки джерел за темами / Compact clock

Добірка наукової літератури з теми "Compact clock"

Автор: Grafiati
Опубліковано: 14 березня 2023

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Статті в журналах з теми "Compact clock"

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Khabarova, Ksenia, Denis Kryuchkov, Alexander Borisenko, Ilia Zalivako, Ilya Semerikov, Mikhail Aksenov, Ivan Sherstov, Timur Abbasov, Anton Tausenev, and Nikolay Kolachevsky. "Toward a New Generation of Compact Transportable Yb+ Optical Clocks." Symmetry 14, no. 10 (October 20, 2022): 2213. http://dx.doi.org/10.3390/sym14102213.

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Анотація:
Optical atomic clocks are currently one of the most sensitive tools making it possible to precisely test the fundamental symmetry properties of spacetime and Einstein’s theory of relativity. At the same time, the extremely high stability and accuracy of compact transportable optical clocks open new perspectives in important fields, such as satellite navigation, relativistic geodesy, and the global time and frequency network. Our project aimed to develop a compact transportable optical clock based on a single ytterbium ion. We present the first prototype of the Yb+ clock (298 kg in 1 m3) and present several solutions aimed to improve the clock’s robustness to approach the demands of a space-qualified system. We present spectroscopic studies of a 435.5 nm quadrupole clock transition with Fourier-limited spectra of 25 Hz. The estimated instability of the output frequency at 1 GHz, which was down-converted with an optical frequency comb (OFC), is at the level of 9×10−15/τ, and the long-term instability and inaccuracy are at the level of 5×10−16. As the next steps, we present a new design for the clock laser and the OFC.
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2

Gellesch, Markus, Jonathan Jones, Richard Barron, Alok Singh, Qiushuo Sun, Kai Bongs, and Yeshpal Singh. "Transportable optical atomic clocks for use in out-of-the-lab environments." Advanced Optical Technologies 9, no. 5 (November 26, 2020): 313–25. http://dx.doi.org/10.1515/aot-2020-0023.

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Анотація:
AbstractRecently, several reports with a strong focus on compact, nonstationary optical atomic clocks have been published, including accounts of in-field deployment of these devices for demonstrations of chronometric levelling in different types of environments. We review recent progress in this research area, comprising compact and transportable neutral atom and single-ion optical atomic clocks. The identified transportable optical clocks strive for low volume, weight and power consumption while exceeding standard microwave atomic clocks in fractional frequency instability and systematic uncertainty. Some transportable clock projects additionally address requirements for metrology or serve the joint technology development between industrial and academic stakeholders. Based on the reviewed reports on nonstationary optical atomic clocks, we suggest definitions for transportable, portable and mobile optical atomic clocks. We conclude our article with an overview of possible future directions for developments of optical clock technology.
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3

Liu, Xiaochi, Ning Ru, Junyi Duan, Peter Yun, Minghao Yao, and Jifeng Qu. "High-performance coherent population trapping clock based on laser-cooled atoms." Chinese Physics B 31, no. 4 (March 1, 2022): 043201. http://dx.doi.org/10.1088/1674-1056/ac2d21.

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Анотація:
We present a coherent population trapping clock system based on laser-cooled 87Rb atoms. The clock consists of a frequency-stabilized CPT interrogation laser and a cooling laser as well as a compact magneto-optical trap, a high-performance microwave synthesizer, and a signal detection system. The resonance signal in the continuous wave regime exhibits an absorption contrast of ∼ 50%. In the Ramsey interrogation method, the linewidth of the central fringe is 31.25 Hz. The system achieves fractional frequency stability of 2.4 × 10 − 11 / τ , which goes down to 1.8 × 10−13 at 20000 s. The results validate that cold atom interrogation can improve the long-term frequency stability of coherent population trapping clocks and holds the potential for developing compact/miniature cold atoms clocks.
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4

Yun, Peter, Sinda Mejri, Francois Tricot, Moustafa Abdel Hafiz, Rodolphe Boudot, Emeric de Clercq, and Stéphane Guérandel. "Double-modulation CPT cesium compact clock." Journal of Physics: Conference Series 723 (June 2016): 012012. http://dx.doi.org/10.1088/1742-6596/723/1/012012.

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5

Pechoneri, R. D., S. T. Müller, C. Bueno, V. S. Bagnato, and D. V. Magalhães. "Portable compact cold atoms clock topology." Journal of Physics: Conference Series 733 (July 2016): 012049. http://dx.doi.org/10.1088/1742-6596/733/1/012049.

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6

Ahmed, Mushtaq, Daniel V. Magalhães, Aida Bebeachibuli, Stella T. Müller, Renato F. Alves, Tiago A. Ortega, John Weiner, and Vanderlei S. Bagnato. "The Brazilian time and frequency atomic standards program." Anais da Academia Brasileira de Ciências 80, no. 2 (June 2008): 217–52. http://dx.doi.org/10.1590/s0001-37652008000200002.

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Анотація:
Cesium atomic beam clocks have been the workhorse for many demanding applications in science and technology for the past four decades. Tests of the fundamental laws of physics and the search for minute changes in fundamental constants, the synchronization of telecommunication networks, and realization of the satellite-based global positioning system would not be possible without atomic clocks. The adoption of optical cooling and trapping techniques, has produced a major advance in atomic clock precision. Cold-atom fountain and compact cold-atom clocks have also been developed. Measurement precision of a few parts in 10(15) has been demonstrated for a cold-atom fountain clock. We present here an overview of the time and frequency metrology program based on cesium atoms under development at USP São Carlos. This activity consists of construction and characterization of atomic-beam, and several variations of cold-atom clocks. We discuss the basic working principles, construction, evaluation, and important applications of atomic clocks in the Brazilian program.
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7

LUO, ZHIHONG, YEUNG ON AU, BENJAMIN LAU, and HENRY LAW. "A 0.0052 mm2 COMPACT DIGITAL PLL IN 65 nm CMOS." Journal of Circuits, Systems and Computers 21, no. 08 (December 2012): 1240026. http://dx.doi.org/10.1142/s0218126612400269.

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Анотація:
A novel structure of digital phase locked loop (PLL) is presented in this paper. It uses digitally controlled oscillator (DCO) to generate the clock. At the beginning of each reference clock cycle, the DCO is fully reset and restarts to oscillate to prevent the long term jitter accumulation and increase the loop stability. It uses three types of digital delay control methods, including delay cell number adjust, delay cell load adjust and in cycle load adjust to digitally control the DCO output clock frequency, in order to get wider frequency range and smaller jitter. This digital PLL uses NAND gate as the basic delay cell of ring oscillator, which can completely reset DCO in a very short time. It uses binary search to achieve fast lock and uses shift chain to get better input clock jitter tolerance. This digital PLL has been silicon validated in GLOBALFOUNDRIES 65 nm Generic process. Its chip area is only 0.0052 mm2. In typical condition, DCO's frequency has a wide range between 550 MHz and 2.45 GHz. Its total power is around 1.4 mW when DCO's frequency is 1.8 GHz. This PLL can be locked very fast in 25 divided reference clock cycles, and its output clock jitter is around 18 ps.
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8

Gubin, M. A., A. N. Kireev, A. V. Konyashchenko, P. G. Kryukov, A. V. Tausenev, D. A. Tyurikov, and A. S. Shelkovnikov. "Realisation of a compact methane optical clock." Quantum Electronics 38, no. 7 (July 31, 2008): 613–14. http://dx.doi.org/10.1070/qe2008v038n07abeh013914.

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Kim, Seungjun, Junghoon Jin, and Jongsun Kim. "A Cost-Effective and Compact All-Digital Dual-Loop Jitter Attenuator for Built-Off-Test Applications." Electronics 11, no. 21 (November 7, 2022): 3630. http://dx.doi.org/10.3390/electronics11213630.

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Анотація:
A compact and low-power all-digital CMOS dual-loop jitter attenuator (DJA) for low-cost built-off-test (BOT) applications such as parallel multi-DUT testing is presented. The proposed DJA adopts a new digital phase interpolator (PI)-based clock recovery (CR) loop with an adaptive decimation filter (ADF) function to remove the jitter and phase noise of the input clock, and generate a phase-aligned clean output clock. In addition, by adopting an all-digital multi-phase multiplying delay-locked loop (MDLL), eight low-jitter evenly spaced reference clocks that are required for the PI are generated. In the proposed DJA, both the MDLL and PI-based CR are first-order systems, and so this DJA has the advantage of high system stability. In addition, the proposed DJA has the benefit of a wide operating frequency range, unlike general PLL-based jitter attenuators that have a narrow frequency range and a jitter peaking problem. Implemented in a 40 nm 0.9 V CMOS process, the proposed DJA generates cleaned programmable output clock frequencies from 2.4 to 4.7 GHz. Furthermore, it achieves a peak-to-peak and RMS jitter attenuation of –25.6 dB and –32.6 dB, respectively, at 2.4 GHz. In addition, it occupies an active area of only 0.0257 mm2 and consumes a power of 7.41 mW at 2.4 GHz.
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Hoang, Anh The, Ziyu Shen, Kuangchao Wu, An Ning, and Wenbin Shen. "Test of Determining Geopotential Difference between Two Sites at Wuhan Based on Optical Clocks’ Frequency Comparisons." Remote Sensing 14, no. 19 (September 28, 2022): 4850. http://dx.doi.org/10.3390/rs14194850.

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Анотація:
Applications of optical clocks in physical geodesy for determining geopotential are of increasing interest to scientists as the accuracy of optical clocks improves and the clock size becomes more and more compact. In this study, we propose a data processing method using the ensemble empirical mode decomposition technique to determine the geopotential difference between two sites in Wuhan based on the frequency comparison of two optical clocks. We use the frequency comparison record data of two Ca+ optical clocks based on the optical fiber frequency transfer method, provided by the Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences (Wuhan, China). By optical clock comparisons we obtained a geopotential difference of 42.50 ± 1.03 m2∙s−2 (equivalent to height difference of 4.33 ± 0.11 m) between the two sites, which is excellent compared to the geopotential difference of 42.56 ± 0.29 m2∙s−2 (equivalent to height difference of 4.34 ± 0.03 m) measured by a spirit leveling. The results show that the optical fiber frequency transfer method is promising in determining the geopotential and potential for unifying the world height system.
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Більше джерел

Дисертації з теми "Compact clock"

1

GOZZELINO, MICHELE. "Pulsed rubidium clock towards space applications." Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2836782.

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2

Bomstad, Wayne Roger. "An ultra-compact antenna test system and its analysis in the context of wireless clock distribution." [Gainesville, Fla.]: University of Florida, 2002. http://purl.fcla.edu/fcla/etd/UFE0000507.

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3

Trémine, Stéphane. "Etude du refroidissement laser d'atomes de césium 133 dans un champ de speckle 3D et réalisation d'une horloge atomique compacte." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066133/document.

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Анотація:
Le projet HORACE consiste en la réalisation d'une horloge atomique compacte de hautes performances exploitant le refroidissement laser d'atomes de 133Cs en "lumière isotrope", en visant principalement le marché des horloges embarquées. Afin d'obtenir un dispositif de faible encombrement, nous réalisons en un lieu unique l'ensemble des phases de la séquence d'horloge (refroidissement, préparation, interrogation et détection). Ceci est rendu possible grâce à l'utilisation d'une cavité d'interrogation à la fois résonnante à la fréquence de la transition d'horloge, et faisant office de sphère intégrante pour la lumière de refroidissement. L'essentiel du travail de thèse présenté ici est consacré à l'étude expérimentale du refroidissement dans le champ de speckle 3D généré à l’intérieur de cette cavité. En limitant le refroidissement à une simple phase de capture, environ 3x108 atomes sont refroidis à des températures cinétiques inférieures à 60 K. Nous montrons par ailleurs qu'une répartition inhomogène de l'énergie optique dans la cavité conduit à scinder la phase de refroidissement sub-Doppler en deux étapes. Malgré le caractère aléatoire de la polarisation entre « grains » de speckle adjacents, la dynamique du refroidissement en régime sub-Doppler que nous observons est identique à celle suivie par des atomes refroidis au sein d’un réseau optique conventionnel. La dernière partie de ce mémoire est consacrée à l’aspect métrologique du projet où la séquence complète de l’horloge est démontrée pour la 1ère fois dans une zone d’interaction unique. Une stabilité relative de fréquence de 2x10-13-1/2 est attendue pour un fonctionnement terrestre de l’horloge
The HORACE project consists in the development of a high-performance compact atomic clock based on isotropic laser cooling of 133Cs atoms, targeting the needs for on-board clocks. In order to minimize the clock size, the entire clock sequence is performed inside one interaction zone only, including atomic cooling, preparation, interrogation and detection. This is made possible with a microwave interrogation cavity that is both resonant at the clock transition frequency, and used as an integrating sphere for the cooling light as well. This thesis work is mainly dedicated to the experimental study of the atomic cooling in the 3D speckle field generated inside the cavity. By limiting the cooling sequence to a capture phase, about 3x108 atoms can be cooled to kinetic temperatures lower than 60 microkelvins. Besides, we show that an inhomogeneous optical energy repartition in the cavity leads us to perform the sub-Doppler cooling phase in 2 steps. Despite random polarization change from one speckle grain to another, the atomic cooling dynamics observed in the sub-Doppler regime is similar to the one observed in conventional optical lattices. The last part of this thesis is devoted to the metrological aspect where the entire clock sequence is demonstrated for the first time at the same place. The fractional frequency stability of 2x10-13-1/2 should be reached on Earth
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4

Kroemer, Eric. "Etude du déplacement collisionnel de la fréquence d'horloge du césium en présence du gaz tampon hélium ou xénon. Applications pour microcellules à haute température." Thesis, Besançon, 2015. http://www.theses.fr/2015BESA2047/document.

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Анотація:
Ce mémoire présente l'étude du déplacement collisionnel de la fréquence d'horloge du césium en présence du gaz tampon hélium ou xénon. L'introduction d'un gaz tampon dans les cellules à vapeur alcaline est nécessaire pour diminuer la largeur de raie de la résonance CPT par effet Dicke. Cependant, la présence de gaz tampon induit un déplacement quadratique de la fréquence d'horloge en fonction de la température de la cellule. Il est possible d'annuler la dépendance thermique du déplacement collisionnel en se plaçant à une température, dite d'inversion, déterminée par le ratio de gaz tampons introduits dans la cellule. Cette température est un point de fonctionnement de choix pour l'opération d'horloges atomiques miniatures et nécessite d'être de l'ordre de 90 voire 100 °C pour les applications à contraintes environnementales sévères. Nous avons mesuré les valeurs des coefficients de déplacement collisionnel de la fréquence d’horloge du césium en présence d’hélium et déterminé pour la première fois la valeur du coefficient quadratique en température. Concernant le xénon, les mesures des valeurs des coefficients de déplacement collisionnel sont incertaines en raison du caractère cubique non-attendu du déplacement collisionnel de la fréquence d’horloge du césium en présence de xénon. Ce comportement serait attribué à des interactions avec les molécules transitoires de van der Waals. Nous avons également établi qu'un mélange de gaz tampon néon-hélium permet d'obtenir des températures d'inversion supérieures à 80 °C. Des mesures dans des micro-cellules ont révélé des températures de l'ordre de 89 à 94 °C pour des mélanges à quelques pourcents d'hélium
This thesis presents a study on collisional shift of cesium clock frequency in the presence of helium or xenon buffer gas. Introduction of buffer gas in alkaline vapour cells is necessary to narrow the CPT line-width by Dicke effect. Nevertheless, buffer gas induces a quadratic shift of the clock frequency versus temperature cell. Cancellation of collisional shift temperature dependence is possible at a so-called inversion temperature depending on the buffer gas ratio. This inversion temperature is great working point for micro atomic clocks. This temperature is required to be 90 or even 100 °C, especially to work in harsh environmental constraints. We measured collisional shift coefficients of cesium clock frequency in presence of helium buffer gas and we determined for the first time the value of the quadratic coefficient. About xenon buffer gas, the measurement of collisional shift coefficients is more difficult because of non-expected cubic behavior of collisional clock frequency shift which could be linked to the interaction with van der Waals molecules. We established that a neon-helium buffer gas mixture could allow an inversion temperature superior to more than 80 °C. Inversion temperatures from 89 to 94 °C are measured in cesium vapor microcells filled with a mixture containing a few percent of helium
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5

Muller, Stella Torres. "Padrão de frequência compacto." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-11052010-154900/.

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Анотація:
Apresentamos os aspectos mais relevantes para a construção e caracterização de um padrão primário de tempo e frequência compacto. Nesse sistema a amostra de átomos de referência é preparada a partir de uma armadilha magneto-óptica. Após a obtenção de uma amostra significativa de átomos os feixes laser são desligados e, durante a expansão livre, a nuvem atômica é submetida a uma sequência de pulsos de micro-ondas que caracterizam o método de Ramsey. Os pulsos de micro-ondas são aplicados em uma cavidade de micro-ondas, esculpida dentro da câmara de vácuo. Todo o ciclo de funcionamento é implementado dentro dessa cavidade e por esse motivo o padrão é considerado compacto. Quando os átomos são interrogados com pulsos de τ = 1 ms separados por Τ = 8 ms obtemos uma largura a meia altura da franja central de 52 Hz e uma estabilidade a curto prazo de 10-13. Alguns causadores de deslocamentos de frequência foram avaliados.
We present some relevant aspects for the construction and characterization of a compact primary frequency standard. In this system, the atomic ensemble is prepared with a magnetooptical trap. Once a significant number of cold atoms is obtained, the laser beams are turned off and, during the free expansion, the cloud is submitted to a sequence of two microwave pulses, characterizing the well-known Ramsey method. The microwave pulses are applied in a microwave cavity that was sculpted inside the vacuum chamber. All the working cycle takes place into this cavity. When the atoms are interrogated by two pulses of τ = 1 ms separated by Τ = 8 ms, the linewidth of the central fringe is 52 Hz and a short-term stability 10-13 is observed. Some frequency shifts were evaluated.
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6

Reinhard, Friedemann. "Design and construction of an atomic clock on an atom chip." Paris 6, 2009. https://tel.archives-ouvertes.fr/tel-00414386.

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Анотація:
Nous décrivons la conception et la construction d'une horloge atomique sur une puce à atomes, visant une stabilité de quelques 10-13 à 1s et une application en tant qu'étalon secondaire. Cette horloge est basée sur la transition à deux photons entre les sous-états hyperfins |F=1,mF=-1> et |2,1> de l'état fondamental de l'atome 87Rb. Elle interroge cette transition en effectuant une spectroscopie de type Ramsey, soit sur un nuage thermique d’atomes froids, soit sur un condensat de Bose-Einstein (BEC). Contrairement aux horloges à fontaines, ce nuage est magnétiquement piégé sur une puce à atomes. Nous décrivons d'une part un modèle théorique de la stabilité d'horloge, d'autre part un montage expérimental dédié, capable de contrôler le champ magnétique à un niveau relatif de 10-5 et doté d'une puce hybride, qui contient des conducteurs à courant continu ainsi qu'un guide d'onde pour acheminer la micro-onde d'interrogation
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7

Von, Bandel Nicolas. "Development and study of low noise laser diodes emitting at 894 nm for compact cesium atomic clocks." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTS003/document.

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Анотація:
Ce travail de thèse porte sur la conception, la réalisation et l'étude de sources laser à semi-conducteur de haute cohérence, émettant à 894 nm, pour application aux horloges atomiques Césium compactes pompées optiquement, dans un contexte de développement industriel. Nous nous intéressons plus particulièrement aux lasers à émission par la tranche, dits "Distributed-Feedback" (DFB), pompés électriquement. L'objectif est d'obtenir un laser monomode en fréquence, à faible seuil, à rendement optique élevé et de largeur de raie inférieure à 1 MHz. Nous traitons d'abord de la conception et de la caractérisation au 1er ordre des diodes DFB, jusqu'à leur mise en modules pour horloge, puis nous effectuons une étude approfondie des propriétés physiques de l'émission laser en terme de cohérence temporelle, en introduisant une nouvelle méthode universelle de caractérisation du bruit de fréquence optique. Enfin, nous nous intéressons aux propriétés spectrales de l'émission en configuration d'asservissement sur une raie de fluorescence du Césium ("Dither-Locking"). Nous montrons que les propriétés intrinsèques du composant satisfont aux exigences du système industriel tel qu'il a été défini lors de l'étude
This PhD work deals with the design, the fabrication and the study of high-coherence semiconductor laser sources emitting at 894 nm, for application to compact, optically-pumped cesium atomic clocks in an industrial context. We are particularly interested in the electrically pumped "Distributed-Feedback" in-plane laser diodes (DFB). The aim is to obtain a low-threshold, single-mode laser with high optical efficiency and a linewidth of less than 1 MHz. We first deal with the design and first-order characterization of the DFB diodes until they are put into modules for the clock. We then carry out an in-depth study of the physical properties of the laser emission in terms of coherence time. For that purpose, a new universal method for characterizing the optical frequency noise is introduced. Finally, we look further into the spectral properties of the emission in a servo configuration on a fluorescence line of the cesium ("Dither-Locking"). We show that the intrinsic properties of the component satisfy the requirements of the industrial system as defined in the study
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8

Tricot, Francois. "Analyse et réduction des sources d'instabilitè de fréquence dans une horloge CPT compacte." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS037/document.

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Анотація:
Ce travail de thèse effectué dans le cadre d’un contrat CIFRE-Défense porte sur l’étude des sources d’instabilité de fréquence d’une horloge atomique basée sur le piégeage cohérent de population. L’objectif est de démontrer une stabilité de fréquence d’horloge de l’ordre de 10-13 tau-1/2 jusque 10 000 s. Une cellule de vapeur de césium est utilisée avec un schéma d’excitation à fort contraste en utilisant des polarisations linéaires croisées et avec une interrogation impulsionnelle de type Ramsey. Un chapitre d’abord consacré aux sources de bruit à court terme présente les travaux réalisés pour réduire le bruit de phase et le bruit de puissance laser, limitant tous deux les performances de l’horloge à 1 s d’intégration. L’optimisation de la chaine micro-onde avec un nouvel oscillateur local, et la réalisation d’un asservissement de puissance performant ont permis d’améliorer la stabilité de fréquence à 2,3x10-13 à 1 s. L’analyse des fluctuations des paramètres de fonctionnement (puissance laser, champ magnétique, température, etc.) et la mesure de la fréquence d’horloge montrent que les variations de fréquence à moyen terme sont majoritairement limitées par les variations de puissance laser et celles du champ magnétique à 2x10-14 à 2 000 s. Ces analyses démontrent aussi que les fluctuations de puissance laser, malgré l’asservissement, sont liées aux fluctuations de polarisation via les fluctuations de température de l’expérience. Pour finir, les études d’un laser bifréquence et bipolarisation pour une horloge CPT compacte sont présentées, ouvrant la voie vers l’industrialisation en réduisant le banc optique
This thesis work has been granted by a CIFRE-Défense contract to study the frequency stabilities of an atomic clock based on coherent population trapping. The objective is to demonstrate a frequency stability in the range of 10-13 tau-1/2 up to 10 000 s. A caesium vapour cell is used with a high-contrast excitation scheme using cross linear polarisations and a Ramsey interrogation. The short-term frequency stability is presented with the reduction of the phase and the laser power noise, both limiting clock performance at 1 s integration time. The optimisation of the microwave chain with a new local oscillator, and the implementation of a very low noise power lock loop have improved the frequency stability down to 2,3x10-13 at 1 s integration time. The fluctuations analysis of the operating parameters (laser intensity, magnetic field, temperature, etc.) and the measurement of the clock frequency show that the medium-term frequency instability is mostly limited by laser power and magnetic field fluctuations at the level of 2x10-14 at 2 000 s integration time. These analyses also show that laser power fluctuations, despite servo loop control, are related to polarisation fluctuations through temperature fluctuations inside the experiment isolation box. Finally, the studies of a dual-frequency and dual-polarisation laser for a compact CPT clock are presented, paving the way to industrialisation by reducing the optical bench
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9

McGahey, Christopher Shawn. "Harnessing nature's timekeeper." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28255.

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Анотація:
Thesis (M. S.)--History, Technology and Society, Georgia Institute of Technology, 2009.
Committee Chair: Usselman, Steven; Committee Member: Ceccagnoli, Marco; Committee Member: Giebelhaus, August; Committee Member: Hunt, William; Committee Member: Krige, John.
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Yu, Jen-Tsung, and 游仁宗. "A Compact Delay-Recycled Clock Skew-Compensation And/Or Duty-Cycle-Correction Circuit." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/34570195575256761660.

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碩士
國立暨南國際大學
電機工程學系
99
A clock skew-compensation and/or duty-cycle correction circuit (CSADC) is indispensably required to maximize the performance of a synchronous double edge clocking system. Most conventional CSADC adopted a cascade structure that inherits a lower performance property that is causing a slower the locking procedure, meanwhile the dual loop design results in more design complexity. In this thesis, a compact delay-recycled CSADC was proposed. There are two significant design concepts in the CSADC. The first is a fast locking and low power measure-and-tuned architecture. The second is a bandwidth augmentation technique. Compared to conventional CSADCs, the proposed circuit achieves at least a 4.24 times reduction in power, a 7.93 times reduction in power bandwidth ratio, and a 1.11 times reduction in lock-in cycles. In TSMC 0.18-μm 1P6M 1.8V CMOS process, the “input signal frequency range” of the proposed CSADC from 300MHz to 2GHz, and the corrected duty cycle variation ranges from 48.41% to 55.51% are confirmed through HSPICE circuit simulation. When the clock frequency is 2GHz, the acceptable input duty cycles ranges from 30% to 70%. Besides, the aligned phase error and power consumption are 67ps and 5.87mW, respectively.
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Книги з теми "Compact clock"

1

Company, Atkins Clock. Illustrated catalogue of clocks manufactured by the Atkins Clock Company, Bristol, Conn. Bristol, Conn: American Clock & Watch Museum, 1999.

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Geller, Clint B. A study of E. Howard & Co. watchmaking innovations, 1858-1875 by Clint Geller. Columbia, PA: National Association of Watch and Clock Collectors, 2005.

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Unitt, Doris Joyce. Arthur Pequegnat clocks: With history & price guide. Peterborough, Ont: Clock House Publications, 1985.

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Townsend, George E. E. Howard & Co. watches, 1858-1903. Kansas City, Mo. (P.O. Box 9808, Kansas City 64134): Heart of America Press, 1985.

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5

Ly, Tran Duy. Seth Thomas clocks & movements: A guide to identification and prices. Arlington, Va: Arlington Book Co., 1985.

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Seth Thomas clocks & movements. 3rd ed. [Johnson City, TN: Arlington Book Co.], 2004.

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Herrmann, Wayne. The wonderful world of pendulettes: Lux, Keebler & Westclox. Merriam, Ks: R & W Publishers, 2000.

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E, Connell James, ed. The Canada and Hamilton clock companies. Erin, Ont: Boston Mills Press, 1986.

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Varkaris, Jane. The Canada and Hamilton clock companies. Erin, Ont: Boston Mills Press, 1986.

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10

The watch of the future: The story of the Hamilton electric watch. 2nd ed. Corte Madera, CA: R. Rondeau, 1992.

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Частини книг з теми "Compact clock"

1

Li, Yuanhao, Shaohang Xu, Sifei Chen, Chang Liu, Jiale Wang, Yining Li, and Yanhui Wang. "Research of Light Shift in Pulse Light Detected Compact Cesium Beam Clock." In Lecture Notes in Electrical Engineering, 353–60. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2576-4_31.

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Hogan, Peter A., and Dirk Puetzfeld. "Gravitational (Clock) Compass." In Frontiers in General Relativity, 99–125. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-69370-1_5.

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3

Trautschold, Martin, and Gary Mazo. "Utilities: Clock, Calculator, Compass, and Weather." In iPhone 4 Made Simple, 593–614. Berkeley, CA: Apress, 2010. http://dx.doi.org/10.1007/978-1-4302-3193-6_26.

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4

Bertolucci, Cristiano, Elena Frigato, and Augusto Foà. "The Reptilian Clock System: Circadian Clock, Extraretinal Photoreception, and Clock-Dependent Celestial Compass Orientation Mechanisms in Reptiles." In Biological Timekeeping: Clocks, Rhythms and Behaviour, 223–39. New Delhi: Springer India, 2017. http://dx.doi.org/10.1007/978-81-322-3688-7_10.

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Zhang, Yize, Junping Chen, Xiuqiang Gong, Bin Wu, Jiexian Wang, Sainan Yang, and Mao Li. "Modeling and Application of COMPASS Satellite Orbits and Clocks Predicted Correction." In Lecture Notes in Electrical Engineering, 181–91. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-54743-0_16.

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Xu, Shaohang, Sifei Chen, Chang Liu, Yining Li, Jiale Wang, and Yanhui Wang. "A New Method to Suppress the AC-Stark Shift of Compact Cesium Beam Atomic Clocks." In Lecture Notes in Electrical Engineering, 17–25. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-3146-7_2.

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7

Obukhov, Yuri N., and Dirk Puetzfeld. "Measuring the Gravitational Field in General Relativity: From Deviation Equations and the Gravitational Compass to Relativistic Clock Gradiometry." In Fundamental Theories of Physics, 87–130. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-11500-5_3.

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8

Schmal, Christoph, Gregor Mönke, and Adrián E. Granada. "Analysis of Complex Circadian Time Series Data Using Wavelets." In Methods in Molecular Biology, 35–54. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2249-0_3.

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AbstractExperiments that compare rhythmic properties across different genetic alterations and entrainment conditions underlie some of the most important breakthroughs in circadian biology. A robust estimation of the rhythmic properties of the circadian signals goes hand in hand with these discoveries. Widely applied traditional signal analysis methods such as fitting cosine functions or Fourier transformations rely on the assumption that oscillation periods do not change over time. However, novel high-resolution recording techniques have shown that, most commonly, circadian signals exhibit time-dependent changes of periods and amplitudes which cannot be captured with the traditional approaches. In this chapter we introduce a method to determine time-dependent properties of oscillatory signals, using the novel open-source Python-based Biological Oscillations Analysis Toolkit (pyBOAT). We show with examples how to detect rhythms, compute and interpret high-resolution time-dependent spectral results, analyze the main oscillatory component, and to subsequently determine these main components’ time-dependent instantaneous period, amplitude, and phase. We introduce step-by-step how such an analysis can be done by means of the easy-to-use point-and-click graphical user interface (GUI) provided by pyBOAT or executed within a Python programming environment. Concepts are explained using simulated signals as well as experimentally obtained time series.
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Heinold, Alina, Marc Kuhn, and Meike Grimme. "“Point-and-Click” – B2B-Customer Loyalty in the Internet: An Empirical Study on Potential Antecedents Exemplified at German Company “WERU”." In Celebrating the Past and Future of Marketing and Discovery with Social Impact, 11–24. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-95346-1_6.

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"A Wash." In Compass and Clock, 71–72. Ohio University Press, 2016. http://dx.doi.org/10.2307/j.ctv224tz56.44.

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Тези доповідей конференцій з теми "Compact clock"

1

Newman, Zachary, David Carlson, Andrew Ferdinand, and Scott B. Papp. "Engineered Multi-Output Supercontinuum Generation in Tantala Waveguides for Optical-Lattice-Clock Stabilization." In CLEO: Science and Innovations. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/cleo_si.2022.sm2f.5.

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We create a tantala nanophotonic waveguide circuit to generate supercontinuum spectrum that covers all the wavelength bands required for a strontium optical-lattice clock. The phase-locked supercontinuum is a versatile tool for compact and manufacturable optical clocks.
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2

Le Coq, Y., C. W. Oates, and L. Hollberg. "Ultra-Stable Compact Optical Atomic Clock." In Laser Science. Washington, D.C.: OSA, 2006. http://dx.doi.org/10.1364/ls.2006.lthb4.

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3

Lurie, A., C. R. Locke, C. Perrella, P. S. Light, F. Benabid, and A. N. Luiten. "Towards a compact optical fibre clock." In 2010 Conference on Precision Electromagnetic Measurements (CPEM 2010). IEEE, 2010. http://dx.doi.org/10.1109/cpem.2010.5544157.

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4

Jammi, S., A. Ferdinand, Z. Newman, C. Ropp, W. Zhu, W. Lunden, D. Sheredy, et al. "Integrated Photonics for a Compact Strontium Optical Clock." In CLEO: Science and Innovations. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/cleo_si.2022.sf2k.7.

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We explore photonic-integrated circuits and metasurface optics to generate multiple, large diameter, circularly polarized laser beams for a compact strontium optical clock. We demonstrate an 88Sr magneto-optical trap with integrated photonics in a liter-scale apparatus.
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5

DeNatale, J. F., R. L. Borwick, C. Tsai, P. A. Stupar, Y. Lin, R. A. Newgard, R. W. Berquist, and M. Zhu. "Compact, low-power chip-scale atomic clock." In 2008 IEEE/ION Position, Location and Navigation Symposium. IEEE, 2008. http://dx.doi.org/10.1109/plans.2008.4570007.

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6

Tremine, S., S. Guerandel, D. Holleville, N. Dimarcq, and A. Clairon. "Microwave interrogation in a compact atomic clock." In 18th European Frequency and Time Forum (EFTF 2004). IEE, 2004. http://dx.doi.org/10.1049/cp:20040899.

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Bregazzi, Alan, Etienne Batori, Ben Lewis, Christoph Affolderbach, Gaetano Mileti, Erling Riis, and Paul Griffin. "A compact cold-atom double-resonance clock." In Quantum Sensing, Imaging, and Precision Metrology, edited by Selim M. Shahriar and Jacob Scheuer. SPIE, 2023. http://dx.doi.org/10.1117/12.2657390.

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Laudat, Théo, Konstantin Ott, Mengzi Huang, Vincent Dugrain, Alice Sinatra, Peter Rosenbusch, Carlos Garrido Alzar, and Jakob Reichel. "Creating Spin Squeezing in a Compact Atomic Clock." In Quantum Information and Measurement. Washington, D.C.: OSA, 2017. http://dx.doi.org/10.1364/qim.2017.qf2a.2.

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Poli, N., R. E. Drullinger, G. Ferrari, M. Prevedelli, F. Sorrentino, M. G. Tarallo, and G. M. Tino. "Prospect for a compact strontium optical lattice clock." In Optical Engineering + Applications, edited by R. Jason Jones. SPIE, 2007. http://dx.doi.org/10.1117/12.739057.

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10

Shah, Vishal, Robert Lutwak, Richard Stoner, and Mark Mescher. "A compact and low-power cold atom clock." In 2012 IEEE International Frequency Control Symposium (FCS). IEEE, 2012. http://dx.doi.org/10.1109/fcs.2012.6243691.

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Звіти організацій з теми "Compact clock"

1

Buell, W. F., and B. Jaduszliwer. Compact CW Cold Beam Cesium Atomic Clock. Fort Belvoir, VA: Defense Technical Information Center, July 2000. http://dx.doi.org/10.21236/ada380684.

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2

Woyczynski, Lauren, Christina Misunas, and Md Irfan Hossain. Building the Adolescent Indicators and Gender Gaps Dashboard. Population Council, 2022. http://dx.doi.org/10.31899/sbsr2022.1014.

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The Adolescent Atlas for Action (A3) is a suite of tools that summarizes the lives and needs of adolescents around the world to promote evidence-based decision-making. Through accessible and easy-to-grasp data just one click away, the A3 bridges the gap between decisionmakers and evidence to inform policies and programs. The Adolescent Indicators dashboard and Gender Gaps dashboard are two simple but dynamic dashboards that provide insights on the lives of adolescent girls and boys living in low- and middle income countries (LMICs) across 9 thematic domains of wellbeing. The Adolescent Indicators dashboard showcases how adolescent girls or boys are faring under each theme, globally and subnationally, as well as how the indicators across domains are interlinked. The Gender Gaps dashboard allows you to compare gaps by domain and indicator, both globally and subnationally. This brief elaborates on the methodology for developing both dashboards.
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3

Samach, Alon, Douglas Cook, and Jaime Kigel. Molecular mechanisms of plant reproductive adaptation to aridity gradients. United States Department of Agriculture, January 2008. http://dx.doi.org/10.32747/2008.7696513.bard.

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Annual plants have developed a range of different mechanisms to avoid flowering (exposure of reproductive organs to the environment) under adverse environmental conditions. Seasonal environmental events such as gradual changes in day length and temperature affect the timing of transition to flowering in many annual and perennial plants. Research in Arabidopsis and additional species suggest that some environmental signals converge on transcriptional regulation of common floral integrators such as FLOWERING LOCUS T (FT). Here we studied environmental induction of flowering in the model legume Medicago truncatula. Similarly to Arabidopsis, the transition to flowering in M. truncatula is hastened by long photoperiods and long periods of vernalization (4°C for 2-3 weeks). Ecotypes collected in Israel retain a vernalization response even though winter temperatures are way above 4°C. Here we show that this species is also highly responsive (flowers earlier) to mild ambient temperatures up to 19°C simulating winter conditions in its natural habitat. Physiological experiments allowed us to time the transition to flowering due to low temperatures, and to compare it to vernalization. We have made use of natural variation, and induced mutants to identify key genes involved in this process, and we provide here data suggesting that an FT gene in M.truncatula is transcriptionally regulated by different environmental cues. Flowering time was found to be correlated with MtFTA and MtFTB expression levels. Mutation in the MtFTA gene showed a late flowering phenotype, while over-expressing MtFTA in Arabidopsis complemented the ft- phenotype. We found that combination of 4°C and 12°C resulted in a synergistic increase in MtFTB expression, while combining 4°C and long photoperiods caused a synergistic increase in MtFTA expression. These results suggest that the two vernalization temperatures work through distinct mechanisms. The early flowering kalil mutant expressed higher levels of MtFTA and not MtFTB suggesting that the KALIL protein represses MtFTA specifically. The desert ecotype Sde Boker flowers earlier in response to short treatments of 8-12oc vernalization and expresses higher levels of MtFTA. This suggests a possible mechanism this desert ecotype developed to flower as fast as possible and finish its growth cycle before the dry period. MtFTA and FT expression are induced by common environmental cues in each species, and expression is repressed under short days. Replacing FT with the MtFTA gene (including regulatory elements) caused high MtFTA expression and early flowering under short days suggesting that the mechanism used to repress flowering under short days has diversified between the two species.The circadian regulated gene, GIGANTEA (GI) encodes a unique protein in Arabidopsis that is involved in flowering mechanism. In this research we characterized how the expression of the M.truncatula GI ortholog is regulated by light and temperature in comparison to its regulation in Arabidopsis. In Arabidopsis GI was found to be involved in temperature compensation to the clock. In addition, GI was found to be involved in mediating the effect of temperature on flowering time. We tested the influence of cold temperature on the MtGI gene in M.truncatula and found correlation between MtGI levels and extended periods of 12°C treatment. MtGI elevation that was found mostly after plants were removed from the cold influence preceded the induction of MtFT expression. This data suggests that MtGI might be involved in 12°C cold perception with respect to flowering in M.truncatula. GI seems to integrate diverse environmental inputs and translates them to the proper physiological and developmental outputs, acting through several different pathways. These research enabled to correlate between temperature and circadian clock in M.truncatula and achieved a better understanding of the flowering mechanism of this species.
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