系统误差对相干偏振合成效率的影响

Effects of system errors on coherent polarization beam combining efficiency

基于偏振合成技术,以提高系统的合成效率为目的,针对合束过程中存在的几种主要系统误差进行了系统分析和定量计算。结果表明,相对于重叠误差、角度倾斜和偏振合束器的吸收损耗而言,半波片的调整误差是导致合成效率下降的主要因素,尤其是在系统向多路合成拓展时,其影响更加显著。若偏振合束器自身损耗为0.015,光束倾斜角为2°,重叠误差为5%,则16路光束的偏振合成效率仍高于92.5%;当半波片方位角出现0.045rad的偏差时,即使不考虑其他误差,系统合成效率低于74%。

Based on polarization beam combination technology, system analysis and quantitative calculation of several main system errors in the process of beam combination are conducted to improve the combining efficiency. The results show that, com- pared to overlap error, tilt angle and absorption loss of the polarization beam combiner, the adjustment error of half-wave plate is the main factor causing the decline of combining efficiency. If the loss of polarization beam combiner is 0. 015, the inclination of incident beams is 2°, and the overlap error is 5%, the coherent polarization beam combining efficiency of sixteen beams can be controlled more than 92.5%. When the deviation of the optical axis of half-wave plates is 0. 045 rad, even without other errors, the combining efficiency will drop below 74 %.