以单色标量波衍射理论为基础,研究单色平面波由圆孔衍射产生实现冷分子(或冷原子)光学囚禁的光阱。运用圆孔衍射理论分析讨论了光学偶极阱的光强分布、光学势及偶极力,并导出了有关光阱的几何参量、光强分布、强度梯度及其曲率与光学系统参量(如照明光波的波长、小孔的孔径)间的解析关系。研究表明,当激光功率与波长分别为P=500 W和λ=1.08 μm,小孔半径a=20 μm时,产生囚禁甲烷CH4分子的光阱光学势约为57.9 μK。通过圆孔衍射可实现冷分子或冷原子囚禁,该方案不仅简单可行、操作方便,而且在冷分子物理、原子光学、分子光学和量子光学等领域中有着广阔的应用前景。

Based on the diffraction theory of the monochromatic scalar wave, an optical trap using a red-detuned small-hole diffracted light field is investigated. The intensity distribution of the optical trap and its optical potential and optical dipole force are colculated by aperture diffraction theory, and derive some analytical relations between the characteristic parameters of the optical trap (including geometric parameters, intensity gradients and theirs curvatures) and the parameters of the optical system (including laser wavelength and aperture radius) are derived. The study shows that when P=500 W, λ=1.080 μm and a=20 μm, the optical trapping potential for cold CH4 molecules is about 57.9 μK. So our trap scheme is not only simple and convenient in the manipulation and control of cold molecular (or cold atoms), but also has wide potential applications in the fields of cold molecular physics, atomic optics, molecule optics even quantum optics,and so on.