Tuning the velocity and flux of a low-velocity intense source of cold atomic beam**Project supported by the National Natural Science Foundation of China (Grant Nos. 61473166 and 41404146).

Abstract

We investigate experimentally and numerically the quantitative dependence of characteristics of a low-velocity intensity source (LVIS) of atomic beam on light parameters, especially the polarization of cooling laser along the atomic beam axis (pushing beam). By changing the polarization of the pushing beam, the longitudinal mean velocity of a rubidium atomic beam can be tuned continuously from 10 to 20 m/s and the flux can range from 3 × 108 to 1 × 109 atoms/s, corresponding to the maximum sensitivity of the velocity with respect to the polarization angle of 20 (m/s)/rad and the mean sensitivity of flux of 1.2 × 109 (atoms/s)/rad. The mechanism is explained with a Monte-Carlo based numerical simulation method, which shows a qualitative agreement with the experimental result. This is also a demonstration of a method enabling the fast and continuous modulation of a low-velocity intense source of cold atomic beam on the velocity or flux, which can be used in many fields, like the development of a cold atomic beam interferometer and atom lithography.