包含波面校正的四程放大系统的准直问题研究

为了解决高功率激光系统中, 尤其是多程放大系统中波前畸变校正和光路准直之间的相互干扰问题, 针对包含自适应光学系统的四程放大系统, 利用菲涅耳衍射积分理论, 建立了310 mm×310 mm大口径光束的四程传输模型, 采用坐标扩展变换的方法解决了传统计算中同时需求近、远场高分辨率带来的计算量过大问题; 基于此模型, 比较了质心法、圆拟合法和纯相位匹配滤波等三种图像处理算法对存在波面差的光束的远场中心的处理精度; 分析了波面校正对焦斑位置的影响; 本文内容为四程放大系统准直调整方案的优化提供了重要依据. 关键词： 光束准直 坐标扩展变换 自适应光学 四程放大

Auto-alignment in four-pass amplifier with wavefront correction system

In order to solve the interaction problem between the wavefront distortion correction and optical alignment in a high-power laser system, especially in a multi-pass amplification system, based on fresnel diffraction integral theory, the beam propagation model of 310 mm×310 mm aperture beam in four-pass amplifier is built by analyzing the properties of this system. The problem of excessive amount of calculation, caused by high resolution in traditional calculation, is solved by coordinate transformation method, Using this model, the differences of far-field accuracy among centroid method, circle fitting and pure phase matching filter in beam with wavefront distortion are discussed; what influence the wavefront correction has on focal spot position is analyzed. This article provides an important basis for optimizing collimation adjustment programs in four-pass amplifier.