A compact extended cavity diode laser （ECDL） system operating at 852 nm for small optically pumped cesium （Cs） beam frequency standards was reported. ECDL and a saturated absorption spectroscopy setup were all bui...A compact extended cavity diode laser （ECDL） system operating at 852 nm for small optically pumped cesium （Cs） beam frequency standards was reported. ECDL and a saturated absorption spectroscopy setup were all built in an aluminum box with dimension of 10 × 10 × 7 （cm）. ECDL was based on a Littman-Metcaff configuration, whose free-running linewidth was less than 600 kHz. A digital automatic frequency lock unit （AFLU） was developed to lock the laser frequency to specify Cs absorption lines automatically and re-lock it in case of lock broken. With AFLU, the laser frequency was continuously locked for several weeks.展开更多
We are developing a compact rubidium atomic beam frequency standard with optical pumping and detection. The cavity for microwave interrogation is an important part of the clock. The cavity in our design is a Ramsey-ty...We are developing a compact rubidium atomic beam frequency standard with optical pumping and detection. The cavity for microwave interrogation is an important part of the clock. The cavity in our design is a Ramsey-type, E-bend one, which is the same as the conventional method in most cesium beam clocks. Requirements for the design are proposed based on the frequency shift associated with the cavity. The basic structure of the cavity is given by theoretical analysis and detailed dimensions are determined by means of electromagnetic field simulation with the help of commercial software.The cavity is manufactured and fabricated successfully. The preliminary test result of the cavity is given, which is in good agreement with the simulation. The resonant frequency is 6.835 GHz, equal to the clock transition frequency of87 Rb, and the loaded quality factor is 500. These values are adjustable with posts outside the cavity. Estimations on the Ramsey line width and several frequency shifts are made.展开更多
A method is presented to improve the laser frequency stabilization for the optical pumping cesium clock. By comparing the laser frequency stabilization of different schemes, we verify that the light angle is an import...A method is presented to improve the laser frequency stabilization for the optical pumping cesium clock. By comparing the laser frequency stabilization of different schemes, we verify that the light angle is an important factor that limits the long-term frequency stability. We minimize the drift of the light angle by using a fiber- coupled output, and lock the frequency of a distributed-feedback diode laser to the fluorescence spectrum of the atomic beam. The measured frequency stability is about 3.5 ×10^-11 at i s and reaches 1.5 × 10^-12 at 2000s. The Allan variance keeps going down for up to thousands of seconds, indicating that the medium- and long-term stability of the laser frequency is significantly improved and perfectly fulfills the requirement for the optical pumping cesium clock.展开更多
文摘A compact extended cavity diode laser （ECDL） system operating at 852 nm for small optically pumped cesium （Cs） beam frequency standards was reported. ECDL and a saturated absorption spectroscopy setup were all built in an aluminum box with dimension of 10 × 10 × 7 （cm）. ECDL was based on a Littman-Metcaff configuration, whose free-running linewidth was less than 600 kHz. A digital automatic frequency lock unit （AFLU） was developed to lock the laser frequency to specify Cs absorption lines automatically and re-lock it in case of lock broken. With AFLU, the laser frequency was continuously locked for several weeks.
基金Project supported by the National Natural Science Foundation of China(Grant No.11174015)
文摘We are developing a compact rubidium atomic beam frequency standard with optical pumping and detection. The cavity for microwave interrogation is an important part of the clock. The cavity in our design is a Ramsey-type, E-bend one, which is the same as the conventional method in most cesium beam clocks. Requirements for the design are proposed based on the frequency shift associated with the cavity. The basic structure of the cavity is given by theoretical analysis and detailed dimensions are determined by means of electromagnetic field simulation with the help of commercial software.The cavity is manufactured and fabricated successfully. The preliminary test result of the cavity is given, which is in good agreement with the simulation. The resonant frequency is 6.835 GHz, equal to the clock transition frequency of87 Rb, and the loaded quality factor is 500. These values are adjustable with posts outside the cavity. Estimations on the Ramsey line width and several frequency shifts are made.
基金Supported by the National Fundamental Research Program of China under Grant No 2011CB921501the National Natural Science Foundation of China under Grant Nos 91336103,10934010 and 61078026
文摘A method is presented to improve the laser frequency stabilization for the optical pumping cesium clock. By comparing the laser frequency stabilization of different schemes, we verify that the light angle is an important factor that limits the long-term frequency stability. We minimize the drift of the light angle by using a fiber- coupled output, and lock the frequency of a distributed-feedback diode laser to the fluorescence spectrum of the atomic beam. The measured frequency stability is about 3.5 ×10^-11 at i s and reaches 1.5 × 10^-12 at 2000s. The Allan variance keeps going down for up to thousands of seconds, indicating that the medium- and long-term stability of the laser frequency is significantly improved and perfectly fulfills the requirement for the optical pumping cesium clock.
