液晶波前校正器校正水平方向上的大气湍流

Correction of Turbulence in Horizontal Direction Using a Liquid Crystal Wave-Front Corrector

利用液晶波前校正器和哈特曼波前传感器组成的自适应光学系统对水平方向500 m的大气湍流进行校正。首先测定了液晶波前校正器(LCWFC)的位相调制特性,测定结果表明其可以实现一个波长的调制量,同时利用Gamma校正实现了位相和灰度之间的线性调制关系。然后将该系统与孔径220 mm的望远镜进行对接。液晶自适应校正后,波面均方根误差降低到0.06λ,实现了0.68″'的系统衍射极限分辨。实验结果表明:液晶波前校正器可以很好地校正水平方向500 m的大气湍流扰动。

An adaptive optics system integrated with a LCWFC and a Shack-Hartmann wave-front sensor （WFS） were used to correct the turbulence in horizontal direction. Firstly, the phase modulation characteristic of the wave-front corrector was measured. The result showed that it can reach the modulation of 1 wave length. Meanwhile, the linear curve between phase modulation and voltage was gained by Gamma correction. At last, this system was combined with a 220 mm diameter telescope. After correction, the wavefront error was reduced to 0.06k and the diffractive limits 0.68＂ was also reached. The result shows that this system can corrected the turbulence effectively.