反射式液晶空间光调制器(LC—SLM)反射基板的曲率误差和液晶盒的边缘场效应导致波前模拟精度下降问题,本文研究用LC-SLM模拟波前,通过静态误差补偿法和残差反馈法,探讨提高波前模拟精度的有效方法。实验结果表明,LC-SLM能较好模拟基于Zernike多项式的离焦、像散、彗差和球差等8项波像差,但是具有一定的模拟误差,均方根误差(RMS)值平均为0.2653,,静态误差补偿法和残差反馈法使波前模拟误差RMS值分别降低到0.2233.和0.170),,残差反馈法更有效。提高波前模拟精度能够使LC—SLM在自适应光学技术、飞秒激光加工、实时全息显示和光学测量等领域具有更大的应用前景。
Liquid crystal spatial light modulator (LC-SLM) is a perfect wavefront generator. As a dynamic diffractive device,it has some advantages such as high resolution,low cost, small-size pixels and realtime programming. For a reflecting LC-SLM, the curvature error of its reflective suhstrate and the fringe field effect of liquid crystal cell can reduce the wavefront generation precision tO limit the device's application in wavefront control field. We research the wavefront generation method using liquid crystal spatial light modulator. In order to find an effective method to improve the wavefront generatio precision, the static-error compensation and residual-error feedback methods are proposed. The experimental results show that liquid crystal spatial light modulator can give good performance on generating eight wavefront aberations including defocus, astigmatism, coma and spherical aberration based on Zernike polynomials. But the RMS of generation errors is averagely 0. 265λ. The RMS of generation errors respectively reduces by 0. 223), and 0. 170λ by using static-error compensation and residual-error feedback methods, and abviously the latter method is more effective. Improving the wavefront generation precision can make LC-SLM have wide application in adaptive optic, femtosecond laser processing, real-time holog-raphy display and optical measurement fields.