用错位相位光栅产生的可调光学双阱

Generation of an adjustable double-well optical trap by shift phase gratings

提出了用相位型错位光栅产生光学双阱的新方案.用平面光波(或TEM00模式高斯光波)照射、正透镜聚焦,在透镜焦平面上产生的适用于冷原子或冷分子囚禁的多对可调光学双阱.计算和推导了双阱的光强分布、强度梯度以及光阱的几何参数与光学系统参数间的解析关系,研究了双阱到单阱三种不同的演化过程.同时还计算了光学双阱囚禁冷原子的光学偶极势和光子散射速率.研究发现,该方案不仅简单可行、操作方便,而且在原子物理、原子光学、分子光学和量子光学领域中有着广阔的应用前景.

A novel scheme was proposed to form the double-well optical trap by using shift phase gratings. A few pairs of adjustable double-well optical traps for trapping cold atoms or cold molecules were formed on the focal plane when the gratings were illuminated by plane light wave （or TEM00 mode Gaussian light wave） and focused by positive lens. The intensity distribution was calculated, and then the intensity distribution gradients as well as the analytical relations between geometrical parameters of the traps and the parameters of the optical system were derived. At the same time, three different evolution processes from double- well to unit-well were investigated. Also, optical dipole potential and photon scattering rate of the trapped cold atoms were calculated. The results show that the scheme not only is simple and convenient to realize, but also has wide application prospect in many fields, such as atomic physics, atomic optics, molecular optics and quantum optics.