高斯激光驻波场沉积Na原子的量子理论分析

利用量子理论,通过CRANK-NICOLSON数值方法对23Na原子受激光驻波场作用的物理过程进行模拟.模拟结果表明:正失谐时,原子以λ/2为周期会聚在驻波光场中波节处.随着光势阱加深或原子纵向速度改变,原子会聚结果分别符合薄透镜、厚透镜及沟道化模型.厚透镜模型中,当原子纵向速度增加,原子密度峰位置沿z方向向后漂移,峰在z方向半高宽增加.当激光功率增加或激光束腰减小,会聚面上峰半高宽减小,对比度增加,峰值增加.

Quantum Analysis of 23Na Atoms Deposition in the Gaussian Laser Standing Wave Field

The effect of a Gaussian laser standing wave on 23Na atoms was simulated by CRANK-NICOLSON numerical algorithm based on quantum-mechanical method. It was found that atoms focus on wave nodes in standing wave light field with a period of λ/2 when the laser is positive-detuned. The focusing results are in accord with thin lens regime, thick lens regime and channeling regime, respectively, as the optical potential is deepened or the longitudinal velocity of atoms is increased. In thick lens regime, the focal plane shifts backward and the full width at half maximum (FWHM) increases, along the z direction, as the atomic longitudinal velocity increases. With increasing laser power or decreasing beam waist, the FWHM of atomic density peak at the focal plane decreases, both the peak value and the contrast increase.