光学阱中Λ增强型灰色黏团冷却辅助原子装载OA北大核心CSTPCD

Λ-enhanced gray molasses cooling(Λ-GMC)technique has been widely used in experiments to prepare cold atomic samples below the sub-Doppler temperature limit.To meet the experimental requirements of cavity quantum electrodynamics systems,we design and construct a wide-range,fast-tuning laser system by integrating tapered amplifiers,fiber phase modulators,etalon,injection locking amplification techniques etc.This laser system achieves a maximum tuning range of 600 MHz and a frequency tuning speed of 5 ns.Based on this laser system,loading atom in a crossed dipole trap assisted by cesium D2 line Λ-GMC cooling in the center of the optical microcavity is studied,and various factors affecting the atom loading are mainly as follows:laser duration τ,three-dimensional magnetic fieldτ(Bx,By,Bz),single-photon detuning ∆,two-photon detuning,δ ratio of cooling beam power to repumping beam power Icool/Irep,and cooling beam power Icooling.The optimal parameters in this system are follows:τ=7 ms,δ=0.2 MHz,∆=5Γ,Icool/Irep=3,and Icool=1.2Isat.Comparing with traditional PGC-assisted loading,the number of atoms is increased about 4 times,and the atomic temperature decreases from 25 μK to 8 μK.This experiment provides important insights for preparing ultracold atomic samples and capturing single atom arrays.