作为导航设备的重要部件,芯片原子钟可作为战术导弹、卫星接收机、小型无人机等所用导航设备的时钟源,也可与陀螺仪和加速度计组合实现微型定位、导航与授时。介绍了相干布局囚禁(Coherent Population Trapping,CPT)现象,以及芯片原子...作为导航设备的重要部件,芯片原子钟可作为战术导弹、卫星接收机、小型无人机等所用导航设备的时钟源,也可与陀螺仪和加速度计组合实现微型定位、导航与授时。介绍了相干布局囚禁(Coherent Population Trapping,CPT)现象,以及芯片原子钟的发展历程,阐述了CPT实现方案的缺点(产生极化暗态、降低原子利用率),并给出了优化方案。此外,分析了微机电系统(Micro Electro Mechanical System,MEMS)加工工艺等用于芯片原子钟制造的关键技术,并对芯片原子钟的发展趋势进行了展望。展开更多
The physics package of a chip-scale atomic clock （CSAC） has been successfully realized by integrating vertical cavity surface emitting laser （VCSEL）, neutral density （ND） filter, λ/4 wave plate, 87Rb vapor cell...The physics package of a chip-scale atomic clock （CSAC） has been successfully realized by integrating vertical cavity surface emitting laser （VCSEL）, neutral density （ND） filter, λ/4 wave plate, 87Rb vapor cell, photodiode （PD）, and magnetic coil into a cuboid metal package with a volume of about 2.8 cm3. In this physics package, the critical component, 87Rb vapor cell, is batch-fabricated based on MEMS technology and in-situ chemical reaction method. Pt heater and thermistors are integrated in the physics package. A PTFE pillar is used to support the optical elements in the physics package, in order to reduce the power dissipation. The optical absorption spectrum of 87Rb D1 line and the microwave frequency correction signal are successfully observed while connecting the package with the servo circuit system. Using the above mentioned packaging solution, a CSAC with short-term frequency stability of about 7 × 10^-10τ-1/2 has been successfully achieved, which demonstrates that this physics package would become one promising solution for the CSAC.展开更多
We present a pair of phase-locked lasers with a 9.2-GHz frequency difference through the injection locking of a master laser to the RF-modulation sideband of a slave diode laser. Using this laser system, a coherent po...We present a pair of phase-locked lasers with a 9.2-GHz frequency difference through the injection locking of a master laser to the RF-modulation sideband of a slave diode laser. Using this laser system, a coherent population trapping （CPT） signal with a typical linewidth of ～ 182 Hz is obtained in a cesium vapor cell filled with 30 Torr （4kPa） of neon as the buffer gas. We investigate the influence of the partial pressure of the neon buffer gas on the CPT linewidth, amplitude, and frequency shift. The results may offer some references for CPT atomic clocks and CPT atomic magnetometers.展开更多
In order to exploit its potential applications, we experimentally study the dependence of ^85 Rb-based coherent population trapping （CPTi resonance on N2 buffer gas with 6 vapor cells filled with natural rubidium and...In order to exploit its potential applications, we experimentally study the dependence of ^85 Rb-based coherent population trapping （CPTi resonance on N2 buffer gas with 6 vapor cells filled with natural rubidium and N2. The experiments are carried out at different pressures and temperatures, and the results reveal that higher cell temperature makes the resonance more sensitive to N2 pressure. Thus, it is importmlt to choose a proper buffer gas pressure at a given cell temperature. This work provides valuable data for the application of 85Rb CPT resonance with a buffer gas of N2.展开更多
Linewidth narrowing and other quantum coherent effects based on three-photon coherent population trapping （CPT） in Ca＋ ions are investigated. If the propagation directions of the three lasers obey the phase matchin...Linewidth narrowing and other quantum coherent effects based on three-photon coherent population trapping （CPT） in Ca＋ ions are investigated. If the propagation directions of the three lasers obey the phase matching condition, the dark linewidth resulting from the CPT can be very narrow, and it can be controlled by adjusting the parameters of the lasers.展开更多
A Cs vapor cell-based atomic clock that uses a lin‖lin pumping scheme with dispersion detection is reported. This atomic clock shows potential for high performance because of its high contrast pumping scheme, and for...A Cs vapor cell-based atomic clock that uses a lin‖lin pumping scheme with dispersion detection is reported. This atomic clock shows potential for high performance because of its high contrast pumping scheme, and for miniaturization because of its simple architecture. The experimental setup and optimal operating parameters for the clock are introduced.The current fractional frequency stability is measured to be 1.3 × 10^-12/■ up to 20s and reaches 3.1 × 10^-13 at 200 s. We have thoroughly investigated the related noise sources that affect clock frequency stability at the 1s and 100s levels. The investigation shows that the laser frequency noise limits the clock frequency stability significantly. The clock performance can be further improved by technically upgrading the laser frequency stabilization setup.展开更多
基金supported by the Knowledge Innovation Project of Chinese Academy of Sciences(Grant No.KGCX2-YW-143)
文摘The physics package of a chip-scale atomic clock （CSAC） has been successfully realized by integrating vertical cavity surface emitting laser （VCSEL）, neutral density （ND） filter, λ/4 wave plate, 87Rb vapor cell, photodiode （PD）, and magnetic coil into a cuboid metal package with a volume of about 2.8 cm3. In this physics package, the critical component, 87Rb vapor cell, is batch-fabricated based on MEMS technology and in-situ chemical reaction method. Pt heater and thermistors are integrated in the physics package. A PTFE pillar is used to support the optical elements in the physics package, in order to reduce the power dissipation. The optical absorption spectrum of 87Rb D1 line and the microwave frequency correction signal are successfully observed while connecting the package with the servo circuit system. Using the above mentioned packaging solution, a CSAC with short-term frequency stability of about 7 × 10^-10τ-1/2 has been successfully achieved, which demonstrates that this physics package would become one promising solution for the CSAC.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11274213, 61205215, 61078051, and 612279002)the National Major Scientific Research Program of China (Grant No. 2012CB921601)+1 种基金the Research Project for Returned Abroad Scholars from Universities of Shanxi Province,China (Grant No. 2012-015)the Project for Excellent Research Team of the National Natural Science Foundation of China (Grant No. 61121064)
文摘We present a pair of phase-locked lasers with a 9.2-GHz frequency difference through the injection locking of a master laser to the RF-modulation sideband of a slave diode laser. Using this laser system, a coherent population trapping （CPT） signal with a typical linewidth of ～ 182 Hz is obtained in a cesium vapor cell filled with 30 Torr （4kPa） of neon as the buffer gas. We investigate the influence of the partial pressure of the neon buffer gas on the CPT linewidth, amplitude, and frequency shift. The results may offer some references for CPT atomic clocks and CPT atomic magnetometers.
基金supported by the National Natural Science Foundation of China (Grant No. 10927403)
文摘In order to exploit its potential applications, we experimentally study the dependence of ^85 Rb-based coherent population trapping （CPTi resonance on N2 buffer gas with 6 vapor cells filled with natural rubidium and N2. The experiments are carried out at different pressures and temperatures, and the results reveal that higher cell temperature makes the resonance more sensitive to N2 pressure. Thus, it is importmlt to choose a proper buffer gas pressure at a given cell temperature. This work provides valuable data for the application of 85Rb CPT resonance with a buffer gas of N2.
基金Acknowledgements We thank Prof. Yi-fu Zhu for useful discus- sion. This work was supported by the National Basic Research Pro- gram of China （Grant No. 2005CB724502）, the National Natural Science Foundation of China （Grant Nos. 10874205 and 10774161） and the Chinese Academy of Sciences.
文摘Linewidth narrowing and other quantum coherent effects based on three-photon coherent population trapping （CPT） in Ca＋ ions are investigated. If the propagation directions of the three lasers obey the phase matching condition, the dark linewidth resulting from the CPT can be very narrow, and it can be controlled by adjusting the parameters of the lasers.
基金Project supported by the National Key Research and Development Progress of China(Grant No.2016YFA030210)the Initiative Program of the State Key Laboratory of Precision Measurement Technology and Instruments,China
文摘A Cs vapor cell-based atomic clock that uses a lin‖lin pumping scheme with dispersion detection is reported. This atomic clock shows potential for high performance because of its high contrast pumping scheme, and for miniaturization because of its simple architecture. The experimental setup and optimal operating parameters for the clock are introduced.The current fractional frequency stability is measured to be 1.3 × 10^-12/■ up to 20s and reaches 3.1 × 10^-13 at 200 s. We have thoroughly investigated the related noise sources that affect clock frequency stability at the 1s and 100s levels. The investigation shows that the laser frequency noise limits the clock frequency stability significantly. The clock performance can be further improved by technically upgrading the laser frequency stabilization setup.
