Pub Date : 2012-04-23DOI: 10.1109/EFTF.2012.6502414
S. Schiller, A. Görlitz, A. Nevsky, S. Alighanbari, S. Vasilyev, C. Abou-Jaoudeh, G. Mura, T. Franzen, U. Sterr, S. Falke, C. Lisdat, E. Rasel, A. Kulosa, S. Bize, J. Lodewyck, G. Tino, N. Poli, M. Schioppo, K. Bongs, Y. Singh, P. Gill, G. Barwood, Yuri B. Ovchinnikov, J. Stuhler, W. Kaenders, C. Braxmaier, R. Holzwarth, A. Donati, S. Lecomte, D. Calonico, F. Levi
The use of ultra-precise optical clocks in space (“master clocks”) will allow for a range of new applications in the fields of fundamental physics (tests of Einstein's theory of General Relativity, time and frequency metrology by means of the comparison of distant terrestrial clocks), geophysics (mapping of the gravitational potential of Earth), and astronomy (providing local oscillators for radio ranging and interferometry in space). Within the ELIPS-3 program of ESA, the “Space Optical Clocks” (SOC) project aims to install and to operate an optical lattice clock on the ISS towards the end of this decade, as a natural follow-on to the ACES mission, improving its performance by at least one order of magnitude. The payload is planned to include an optical lattice clock, as well as a frequency comb, a microwave link, and an optical link for comparisons of the ISS clock with ground clocks located in several countries and continents. Undertaking a necessary step towards optical clocks in space, the EU-FP7-SPACE-2010-1 project no. 263500 (SOC2) (2011–2015) aims at two “engineering confidence“, accurate transportable lattice optical clock demonstrators having relative frequency instability below 1×10−15 at 1 s integration time and relative inaccuracy below 5×10−17. This goal performance is about 2 and 1 orders better in instability and inaccuracy, respectively, than today's best transportable clocks. The devices will be based on trapped neutral ytterbium and strontium atoms. One device will be a breadboard. The two systems will be validated in laboratory environments and their performance will be established by comparison with laboratory optical clocks and primary frequency standards. In order to achieve the goals, SOC2 will develop the necessary laser systems - adapted in terms of power, linewidth, frequency stability, long-term reliability, and accuracy. Novel solutions with reduced space, power and mass requirements will be implemented. Some of the laser systems will be developed towards particularly high compactness and robustness levels. Also, the project will validate crucial laser components in relevant environments. In this paper we present the project and the results achieved during the first year.
{"title":"The space optical clocks project: Development of high-performance transportable and breadboard optical clocks and advanced subsystems","authors":"S. Schiller, A. Görlitz, A. Nevsky, S. Alighanbari, S. Vasilyev, C. Abou-Jaoudeh, G. Mura, T. Franzen, U. Sterr, S. Falke, C. Lisdat, E. Rasel, A. Kulosa, S. Bize, J. Lodewyck, G. Tino, N. Poli, M. Schioppo, K. Bongs, Y. Singh, P. Gill, G. Barwood, Yuri B. Ovchinnikov, J. Stuhler, W. Kaenders, C. Braxmaier, R. Holzwarth, A. Donati, S. Lecomte, D. Calonico, F. Levi","doi":"10.1109/EFTF.2012.6502414","DOIUrl":"https://doi.org/10.1109/EFTF.2012.6502414","url":null,"abstract":"The use of ultra-precise optical clocks in space (“master clocks”) will allow for a range of new applications in the fields of fundamental physics (tests of Einstein's theory of General Relativity, time and frequency metrology by means of the comparison of distant terrestrial clocks), geophysics (mapping of the gravitational potential of Earth), and astronomy (providing local oscillators for radio ranging and interferometry in space). Within the ELIPS-3 program of ESA, the “Space Optical Clocks” (SOC) project aims to install and to operate an optical lattice clock on the ISS towards the end of this decade, as a natural follow-on to the ACES mission, improving its performance by at least one order of magnitude. The payload is planned to include an optical lattice clock, as well as a frequency comb, a microwave link, and an optical link for comparisons of the ISS clock with ground clocks located in several countries and continents. Undertaking a necessary step towards optical clocks in space, the EU-FP7-SPACE-2010-1 project no. 263500 (SOC2) (2011–2015) aims at two “engineering confidence“, accurate transportable lattice optical clock demonstrators having relative frequency instability below 1×10−15 at 1 s integration time and relative inaccuracy below 5×10−17. This goal performance is about 2 and 1 orders better in instability and inaccuracy, respectively, than today's best transportable clocks. The devices will be based on trapped neutral ytterbium and strontium atoms. One device will be a breadboard. The two systems will be validated in laboratory environments and their performance will be established by comparison with laboratory optical clocks and primary frequency standards. In order to achieve the goals, SOC2 will develop the necessary laser systems - adapted in terms of power, linewidth, frequency stability, long-term reliability, and accuracy. Novel solutions with reduced space, power and mass requirements will be implemented. Some of the laser systems will be developed towards particularly high compactness and robustness levels. Also, the project will validate crucial laser components in relevant environments. In this paper we present the project and the results achieved during the first year.","PeriodicalId":6409,"journal":{"name":"2012 European Frequency and Time Forum","volume":"28 1","pages":"412-418"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87264849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-23DOI: 10.1109/EFTF.2012.6502421
F. Hoflinger, Rui Zhang, L. Reindl
In this paper we present a wireless Micro-Inertial Measurement Unit (IMU) which is used for localization of people in indoor areas. The Micro-IMU is built especially for portable applications. The main target of the IMU design was to minimize the size, weight and power consumption, as much as possible whereas the performance is still comparable to commercially available wired IMUs. Through the minimum size the IMU can be integrated into clothes or shoes and provide the full functionality of pedometers. In an experiment the Micro-IMU was mounted on a shoe for detecting the human movement. With sensor data-fusion based on Kalman Filter and ZUPT (Zero Velocity Update) Algorithm we could track a person in an indoor area.
{"title":"Indoor-localization system using a Micro-Inertial Measurement Unit (IMU)","authors":"F. Hoflinger, Rui Zhang, L. Reindl","doi":"10.1109/EFTF.2012.6502421","DOIUrl":"https://doi.org/10.1109/EFTF.2012.6502421","url":null,"abstract":"In this paper we present a wireless Micro-Inertial Measurement Unit (IMU) which is used for localization of people in indoor areas. The Micro-IMU is built especially for portable applications. The main target of the IMU design was to minimize the size, weight and power consumption, as much as possible whereas the performance is still comparable to commercially available wired IMUs. Through the minimum size the IMU can be integrated into clothes or shoes and provide the full functionality of pedometers. In an experiment the Micro-IMU was mounted on a shoe for detecting the human movement. With sensor data-fusion based on Kalman Filter and ZUPT (Zero Velocity Update) Algorithm we could track a person in an indoor area.","PeriodicalId":6409,"journal":{"name":"2012 European Frequency and Time Forum","volume":"18 1","pages":"443-447"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79223777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-23DOI: 10.1109/EFTF.2012.6502356
U. Weinbach, S. Schon
Kinematic orbit positions of Low Earth Orbiting satellites (LEOs) derived from GPS observations are frequently used for single satellite gravity field recovery. Unfortunately, the precision of the kinematic coordinates is compromised by the estimation of the receiver clock synchronization offset in addition to the three kinematic coordinates for every observation epoch. In this paper the potential of receiver clock modeling to improve the precision of the kinematic orbit determination is investigated. The formation flying twin satellites of the Gravity Recovery And Climate Experiment (GRACE) mission are considered as a case study. A unique feature of these satellites is the combination of a dual frequency GPS receiver with an Ultra Stable Oscillator (USO), that provides the required frequency stability for the proposed clock modeling approach. Based on a piece-wise linear clock parametrization with 60 s intervals, a significant reduction of the high-frequency radial orbit differences with respect to a reduced-dynamic orbit is shown.
{"title":"Improved GPS receiver clock modeling for kinematic orbit determination of the GRACE satellites","authors":"U. Weinbach, S. Schon","doi":"10.1109/EFTF.2012.6502356","DOIUrl":"https://doi.org/10.1109/EFTF.2012.6502356","url":null,"abstract":"Kinematic orbit positions of Low Earth Orbiting satellites (LEOs) derived from GPS observations are frequently used for single satellite gravity field recovery. Unfortunately, the precision of the kinematic coordinates is compromised by the estimation of the receiver clock synchronization offset in addition to the three kinematic coordinates for every observation epoch. In this paper the potential of receiver clock modeling to improve the precision of the kinematic orbit determination is investigated. The formation flying twin satellites of the Gravity Recovery And Climate Experiment (GRACE) mission are considered as a case study. A unique feature of these satellites is the combination of a dual frequency GPS receiver with an Ultra Stable Oscillator (USO), that provides the required frequency stability for the proposed clock modeling approach. Based on a piece-wise linear clock parametrization with 60 s intervals, a significant reduction of the high-frequency radial orbit differences with respect to a reduced-dynamic orbit is shown.","PeriodicalId":6409,"journal":{"name":"2012 European Frequency and Time Forum","volume":"110 1","pages":"157-160"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79554351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-23DOI: 10.1109/EFTF.2012.6502335
Tiexin Liu, Wenqing Xu, W.X Chen, J.Y Dai, Y. Zhang, Y. Xie, C. Lin
This paper introduces recently result on passive hydrogen maser of shanghai Astronomical Observatory by single frequency modulation. Digital servo system and analog servo system have been experimented. DDS is used to generate frequency modulation in the RF interrogation chain in both systems. The algorithm separating two errors is used in digital system. The traditional integrator and digital phase shift are used in analog system. An Allan standard deviation of two systems has been tested based on same physical part. Both of them have achieved at σy(τ) < 1×10−12τ−1/2 (1s≤τ≤10000s) and σy (day) <2×10p−14.
{"title":"Recently result on passive hydrogen maser of SHAO by single frequency modulation","authors":"Tiexin Liu, Wenqing Xu, W.X Chen, J.Y Dai, Y. Zhang, Y. Xie, C. Lin","doi":"10.1109/EFTF.2012.6502335","DOIUrl":"https://doi.org/10.1109/EFTF.2012.6502335","url":null,"abstract":"This paper introduces recently result on passive hydrogen maser of shanghai Astronomical Observatory by single frequency modulation. Digital servo system and analog servo system have been experimented. DDS is used to generate frequency modulation in the RF interrogation chain in both systems. The algorithm separating two errors is used in digital system. The traditional integrator and digital phase shift are used in analog system. An Allan standard deviation of two systems has been tested based on same physical part. Both of them have achieved at σ<inf>y</inf>(τ) < 1×10<sup>−12</sup>τ<sup>−1/2</sup> (1s≤τ≤10000s) and σ<inf>y</inf> (day) <2×10p<sup>−14</sup>.","PeriodicalId":6409,"journal":{"name":"2012 European Frequency and Time Forum","volume":"7 1","pages":"69-71"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76101284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-23DOI: 10.1109/EFTF.2012.6502422
J. Belfi, N. Beverini, B. Bouhadef, G. Carelli, D. Cuccato, A. D. Di Virgilio, A. Licciardi, E. Maccioni, A. Ortolan, G. Saccorotti, F. Stefani
We present a summary of the recent results obtained with the “G-Pisa” laser gyroscope prototype in the field of rotational metrology. The experimental apparatus consists in an He-Ne laser having a planar square cavity 1.35 m in side that can be operated both in the vertical and in the horizontal plane. For about one year, the ring laser has been utilized by the Virgo gravitational wave interferometer with the aim of estimating and monitoring the local rotational noise which is degrading the performances of its inertial suspensions. Results in the field of environmental monitoring for the improvement of the suspension control as well as the results in the field of rotational seismology are presented. In the last part of the paper we present some considerations about the possibility of performing a ground-based General Relativity test using an array of ring lasers.
{"title":"Laser gyroscopes for very high sensitive applications","authors":"J. Belfi, N. Beverini, B. Bouhadef, G. Carelli, D. Cuccato, A. D. Di Virgilio, A. Licciardi, E. Maccioni, A. Ortolan, G. Saccorotti, F. Stefani","doi":"10.1109/EFTF.2012.6502422","DOIUrl":"https://doi.org/10.1109/EFTF.2012.6502422","url":null,"abstract":"We present a summary of the recent results obtained with the “G-Pisa” laser gyroscope prototype in the field of rotational metrology. The experimental apparatus consists in an He-Ne laser having a planar square cavity 1.35 m in side that can be operated both in the vertical and in the horizontal plane. For about one year, the ring laser has been utilized by the Virgo gravitational wave interferometer with the aim of estimating and monitoring the local rotational noise which is degrading the performances of its inertial suspensions. Results in the field of environmental monitoring for the improvement of the suspension control as well as the results in the field of rotational seismology are presented. In the last part of the paper we present some considerations about the possibility of performing a ground-based General Relativity test using an array of ring lasers.","PeriodicalId":6409,"journal":{"name":"2012 European Frequency and Time Forum","volume":"31 1 1","pages":"448-452"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78425131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-23DOI: 10.1109/EFTF.2012.6502344
X. Zeng, D. Boiko
We report the first detailed theoretical study of mode-locking dynamics in an active atomic clock based on a 420 nm wavelength, III-nitride vertical external cavity surface emitting laser with a 85Rb vapor cell as the intracavity saturable absorber.
{"title":"Towards first active clock based on mode-locked InGaN VECSEL with rubidium vapor cell saturable absorber","authors":"X. Zeng, D. Boiko","doi":"10.1109/EFTF.2012.6502344","DOIUrl":"https://doi.org/10.1109/EFTF.2012.6502344","url":null,"abstract":"We report the first detailed theoretical study of mode-locking dynamics in an active atomic clock based on a 420 nm wavelength, III-nitride vertical external cavity surface emitting laser with a 85Rb vapor cell as the intracavity saturable absorber.","PeriodicalId":6409,"journal":{"name":"2012 European Frequency and Time Forum","volume":"11 1","pages":"105-108"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78428187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-23DOI: 10.1109/EFTF.2012.6502389
R. Straessle, Y. Petremand, D. Briand, N. D. de Rooij, M. Pellaton, C. Affolderbach, G. Mileti
We report on the realization and evaluation of micro-fabricated alkali vapor cells using a thin-film indium bonding technique. Optical and double-resonance spectroscopy performed on the cells demonstrates their suitability for atomic clock applications. Long-term measurements show a stable pressure inside the cells and therefore an excellent hermeticity of the bonding over several months. The low bonding process temperature of ≤ 140°C combined with good bond strength makes this method a promising candidate for realizing micro-fabricated alkali cells with anti-relaxation wall-coatings.
{"title":"Towards wall-coated microfabricated cells: Alkali vapor-cells using indium thin-film low-temperature bonding","authors":"R. Straessle, Y. Petremand, D. Briand, N. D. de Rooij, M. Pellaton, C. Affolderbach, G. Mileti","doi":"10.1109/EFTF.2012.6502389","DOIUrl":"https://doi.org/10.1109/EFTF.2012.6502389","url":null,"abstract":"We report on the realization and evaluation of micro-fabricated alkali vapor cells using a thin-film indium bonding technique. Optical and double-resonance spectroscopy performed on the cells demonstrates their suitability for atomic clock applications. Long-term measurements show a stable pressure inside the cells and therefore an excellent hermeticity of the bonding over several months. The low bonding process temperature of ≤ 140°C combined with good bond strength makes this method a promising candidate for realizing micro-fabricated alkali cells with anti-relaxation wall-coatings.","PeriodicalId":6409,"journal":{"name":"2012 European Frequency and Time Forum","volume":"10 1","pages":"309-311"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88650650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-23DOI: 10.1109/EFTF.2012.6502425
M. Gubin, M. Frolov, A. Kireev, Y. Korostelin, V. Kozlovskyi, Y. Podmar’kov, A. Shelkovnikov, D. Tyurikov, V. Lazarev, A. Pnev
The mid-IR cw tunable solid state Cr2+:ZnSe laser with spectral density of intrinsic frequency noise less than 30 mHz/Hz1/2 was created. The laser was applied for sub-Doppler spectroscopy of (ν1+ν4) vibrational-rotational band of methane and narrow resonances of saturated dispersion at λ = 2.36 µm were demonstrated for the first time. Characteristics of resonances and low frequency noise of the laser pave the way to a short-term frequency stability at the level of 10−15 – 10−16.
{"title":"Cr:ZnSe laser with 0.03 Hz/Hz1/2 frequency noise for compact methane based OFS","authors":"M. Gubin, M. Frolov, A. Kireev, Y. Korostelin, V. Kozlovskyi, Y. Podmar’kov, A. Shelkovnikov, D. Tyurikov, V. Lazarev, A. Pnev","doi":"10.1109/EFTF.2012.6502425","DOIUrl":"https://doi.org/10.1109/EFTF.2012.6502425","url":null,"abstract":"The mid-IR cw tunable solid state Cr<sup>2+</sup>:ZnSe laser with spectral density of intrinsic frequency noise less than 30 mHz/Hz<sup>1/2</sup> was created. The laser was applied for sub-Doppler spectroscopy of (ν<inf>1</inf>+ν<inf>4</inf>) vibrational-rotational band of methane and narrow resonances of saturated dispersion at λ = 2.36 µm were demonstrated for the first time. Characteristics of resonances and low frequency noise of the laser pave the way to a short-term frequency stability at the level of 10<sup>−15</sup> – 10<sup>−16</sup>.","PeriodicalId":6409,"journal":{"name":"2012 European Frequency and Time Forum","volume":"17 1","pages":"459-461"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90493593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-23DOI: 10.1109/EFTF.2012.6502347
J. Delporte, C. Boulanger, F. Mercier
The stability of on-board clocks is an essential issue in the performance of Global Navigation Satellite Systems (GNSS). We developed a straightforward method (the polynomial method) that allows to determine the short term stability of a GNSS on-board clock for a pass over a ground station driven by a clock, the characteristics of which are better than the space clock we want to characterize. In previous papers [1,2], we validated the method on GPS on-board clocks using IGS clock products as reference. In this paper, we continue this work with GLONASS, Galileo, COMPASS/Beidou and QZSS on-board clocks.
{"title":"Short-term stability of GNSS on-board clocks using the polynomial method","authors":"J. Delporte, C. Boulanger, F. Mercier","doi":"10.1109/EFTF.2012.6502347","DOIUrl":"https://doi.org/10.1109/EFTF.2012.6502347","url":null,"abstract":"The stability of on-board clocks is an essential issue in the performance of Global Navigation Satellite Systems (GNSS). We developed a straightforward method (the polynomial method) that allows to determine the short term stability of a GNSS on-board clock for a pass over a ground station driven by a clock, the characteristics of which are better than the space clock we want to characterize. In previous papers [1,2], we validated the method on GPS on-board clocks using IGS clock products as reference. In this paper, we continue this work with GLONASS, Galileo, COMPASS/Beidou and QZSS on-board clocks.","PeriodicalId":6409,"journal":{"name":"2012 European Frequency and Time Forum","volume":"1 1","pages":"117-121"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90501113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-23DOI: 10.1109/EFTF.2012.6502387
E. Breschi, A. Weis
We report on preliminarily results of push-pull optical pumping (PPOP) on the D1-transition of cesium. PPOP is based on a coherent population trapping effect prepared with polarization-modulated bichromatic light coupling the two ground-state hyperfine levels, the light polarization being modulated at the microwave frequency. With a suitable choice of polarizations, a single specific coherent superposition (dark state) formed by the two mF = 0 sublevels can be prepared under optimal conditions. This increase the contrast of the clock reference signal without significant line-broadening.
{"title":"Push-pull optical pumping on the Cs D1-transition","authors":"E. Breschi, A. Weis","doi":"10.1109/EFTF.2012.6502387","DOIUrl":"https://doi.org/10.1109/EFTF.2012.6502387","url":null,"abstract":"We report on preliminarily results of push-pull optical pumping (PPOP) on the D1-transition of cesium. PPOP is based on a coherent population trapping effect prepared with polarization-modulated bichromatic light coupling the two ground-state hyperfine levels, the light polarization being modulated at the microwave frequency. With a suitable choice of polarizations, a single specific coherent superposition (dark state) formed by the two mF = 0 sublevels can be prepared under optimal conditions. This increase the contrast of the clock reference signal without significant line-broadening.","PeriodicalId":6409,"journal":{"name":"2012 European Frequency and Time Forum","volume":"17 1","pages":"300-303"},"PeriodicalIF":0.0,"publicationDate":"2012-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82091370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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