铬原子束的激光多普勒冷却准直检测实验研究

本文采用基于激光感生荧光（LIF）的位移探测系统检测了铬原子束中轴向定量百分比原子数的冷却准直发散角,评价了激光的多普勒冷却准直效果。实验结果得到当冷却激光功率为45mW,作用长度为24mm,失谐量为-0.5Γ的情况下,铬原子束中轴向定量50%原子数的发散角由冷却准直前的1.07±0.10mrad减小到冷却准直后的0.46±0.10mrad,并且其准直发散角随着冷却激光功率的增加而减小。文章最后用半经典理论数值模拟计算了实验结果并与之作了比较。

Experimental measurement study of laser collimation of a chromium beam by Doppler cooling scheme

In this paper,a size detecting system based on Laser induced fluorescence（LIF）is designed to measure the Cr atomic beam divergence of laser collimation by using one-dimensional transverse Doppler cooling scheme.Under the parameters of cooling laser power of 45mW,interaction distance of 24mm and detuning of-0.5Γ,we observe the angular distribution of Cr atoms（50%quantile） on the beam axis is from 1.07±0.10mrad to 0.46±0.10mrad by laser collimation.we also present detailed measurements of collimation angles over different laser powers and compare and analysis our results with numerical calculation based on the semiclassical model.