The Investigation Of Two-dimensional Collimating Atomic Beam Of Strontium And Detecting Fluorescence Spectrum Of Intercombination Transition

The strontium (Sr) optical lattice clock has a better potential performance thanthe cesium fountain clock. Internationally, it is the forward-looking atomic clockwhich has most research and fastest progress. The clock is most likely for updatesand reproduction defined unit of "seconds" time as the next generation of time andfrequency primary standard clock a decade later.The cold strontium atoms’ preparation is the most important step of strontiumoptical clock. Using laser to two-dimensional (2D) collimate strontium atomic beamis an effective method to achieve a high-flux, low-divergence angle of the atomicbeam, and increase the number of trapped atoms and atom density. Strontium atomsare cooled by using of (5s2p)1S0-(5s5p)3P1intercombination transition forsecondary cooling. In order to facilitate detection, a more effective detection systemis needed. In this paper, the work has focused on the study2D collimation ofstrontium atomic beam and detection of intercombination transition fluorescencespectrum.(1)Using Monte Carlo method theoretical simulates dynamic process of2Dcollimating of strontium atomic beam. The results of the Monte Carlo method arepresented as functions of detuning and power of laser, respectively. The methodprovides some guidance for2D collimating experiments of strontium atom.(2)We experimentally study2D collimation process of strontium atomic beamand achieve the pictures of before and after the two-dimensional collimating. Theatomic fluorescence intensity as function of parameters of laser used to collimate theatomic beam is achieved. The experimental results compared with Monte Carlosimulation are in perfect agreement.(3)We develop fluorescence detection system for the intercombination transition.Based on strontium atoms (5s2)1S0-(5s5p)3P1intercombination transitioncharacteristics, choosing very low input bias current operational amplifier AD549asa preamplifier, we develop a high signal-to-noise ratio, high gain, bias adjustablefluorescent detector. The detector can satisfy the requirement of689nm laserfrequency stabilization and then be used for strontium optical clock.