偏振光束相干合成的理论分析

Theory Analysis of Polarized Beam Coherent Combination

描述了偏振光束相干合成的原理和过程,分析了光束参数、相位差和振幅比变化、光束重合度以及平行度等参数对合成效率的影响,讨论了实施合成的实验参数及方法。结果表明,相对于强度变化,相位差的变化对合成效率的影响是主要的;重合度误差的影响相对较小,在实验的精度内(重合度<2.5%)完全可以忽略;平行度使合成效率发生了最显著的降低。分析认为,大尺寸的光束合成可以有效减少平行度引起的合成损耗,光束直径为8 mm并通过等厚干涉判断光束重合时,受重合度影响的合成效率大于95%。此外,等强度合成是获得最大合成强度、简化实验的最佳合成方式。

The principle and progress of polarized beam coherent combination is described. The influence factors, such as beam parameters, the change of amplitude-ratio and phase-difference, beam overlap-ratio and parallelism on the combining efficiency, are researched. The experimental parameters and methods of operating combining are also discussed. The results show that the influence of phase-difference variation on combining efficiency is much greater rather than the change of amplitude-ratio, and the effect of the overlap-ratio error is so small that it can be ignored when it is smaller than 2.5%. Moreover, the parallelism error makes the combining efficiency have a significant decrease. It is found that combining beams with large beam diameter have a benefit for the effective reduction of combining loss caused by the parallelism error, the combining efficiency is greater than 95 % when the beam diameter is 8 mm and. interference of equal thickness is used to test the coincidence. In addition, beam combination with identical intensity is the best method for getting the maximum intensity and simplifying operation.