一种新空心光束的理论及实验研究

提出了一种用来描述空心光束的新理论模型——空心高斯光束模型，通过控制光束参数可以方便地调制空心光束黑斑的大小.导出了空心高斯光束经傍轴光学系统的解析传输变换公式.利用导出的公式计算分析了空心高斯光束在自由空间的传输特性.在实验上利用矩阵本征值方法设计了能输出空心高斯光束的光学谐振腔，对实验上得到的空心高斯光束进行了传输特性的研究.结果表明，理论和实验相吻合.该空心高斯光束产生的光势阱为控制冷原子提供了一条新途径. 关键词： 空心高斯光束 光学谐振腔 传输特性

Theoretical and experimental study of new dark hollow beams

A new mathematical model named hollow Gaussian beams (HGBs) is introduced to describe the dark hollow beam. The area of the dark region across the HGBs can be easily controlled by properly choosing the beam parameters. An analytical propagation formula for HGBs through paraxial optical system is derived. The evolution properties of the intensity distribution of HGBs in free space propagation are illustrated graphically using the derived propagation formula. By using matrix eigenvalues method, the laser cavity with diffraction optical elements, which can generate the dark hollow beams, was constructed. Dark hollow beams were realized in experiment and its intensity distribution properties in near field and far field were studied. The results derived from the experiment is coincident with those predicted by the theory. The dark hollow beams we have obtained can be used conveniently to analyze atoms manipulation and may provide a new method for atom cooling.