单口径相干合成系统激光光束的M2因子研究

单口径相干合成系统激光光束的光束质量是一个亟待解决的重要问题.基于二阶矩定义, 文中给出了单口径TEM₀₀, TEM₀₁及TEM₁₀两两相干光束M²因子的解析表达式, 并比较分析了束腰宽度、传输距离、振幅之比,以及源场位置矢量对相干光束M²因子的影响, 得到了诸如源场位置参量d₁<100λ时,各相干光束M²因子恒定,反之, 其随位置参量d₁的增大而增大等一些结论.最后,文章对两TEM₀₀模相干光束M²因子的 部分理论进行了实验验证.

Study of the M2 factor for the single-aperture coherent laser beam synthesis system

Beam quality M² factor of the single-aperture coherent laser beam synthesis system is a major problem to be solved. Based on the definition of second-order moment, beam quality M² factors of the coherently combined beam supposed by the basic model TEM₀₀, TEM₀₁and TEM₁₀ are presented by some analytical expressions in this paper. And, the effects produced by the beam waist width, the propagation distance, the ratio of the two amplitudes and the distance between the two coherent sources on the beam quality M² factor are numerically analyzed. Some results show that the beam quality M² factor of the coherently combined beam is unchanged when the propagation distance parameter d₁<100λ. And the experiment is carried to verify some theories of the two TEM₀₀ coherently combined beam.