涡旋光束的自适应光学波前校正技术

涡旋光束是一种具有螺旋波前的光束，其特点是其光强分布为环形，携带有与螺旋波前结构相关的轨道角动量。由于涡旋光束的角量子数可取任意整数，同时不同角量子数的光束之间相互正交，因此可提高光通信系统的信道容量。但涡旋光束在自由空间传输时会受到大气湍流的影响，进而产生波前畸变，因此需要采用自适应波前校正技术对畸变后的光束进行校正。文中对现有的涡旋光束波前校正技术进行了概述，重点介绍了笔者课题组提出的应用GS相位恢复算法和高斯光束探针相结合对涡旋光束波前畸变校正的技术及应用SPGD算法和泽尼克多项式对涡旋光束波前畸变校正的研究工作。

Adaptive optics wavefront correction techniques of vortex beams

Vortex beam is a new kind of beams with helical wavefront. It has an annular intensity distribution,and with orbital angular momentum(OAM) related to the helical wavefront. The OAM state of a vortex beam can be any integer, and vortex beams with different OAM states are mutually orthogonal, which indicates the potential of enlarging the capacity of optical communications. However, when a vortex beam propagates in free space, its wavefront will be distorted by the turbulence of the atmosphere. It is necessary to study how to compensate the wavefront distortion by using adaptive optics system. In this paper, some adaptive optics correction approaches were summarized. Moreover, schemes of correcting distorted vortex beams, which were proposed by our group, were introduced. One scheme was the pre-compensation method by using the GS algorithm and a Gaussian probe beam. The other one was a phase correction method by using a Zernike polynomials-based SPGD algorithm.