利用部分相干光理论,以具有双正交性质的复宗量厄米高斯(EHG)模为基底,推导出激光的EHG模相关系数(MCCs)和M2因子公式,建立了激光的EHG相干模表示与对应的常规厄米-高斯(SHG)相干模表示之间的关系,并讨论了两种典型的应用例。研究结果表明,激光的EHG模相关系数可以通过SHG模相关系数得到;当同阶模式的权重因子相同时,由彼此互不相关的EHG模式叠加而成的光束比由彼此互不相关的SHG模式叠加而成光束的光束质量更好。

By using the theory of partially coherent light and the basis set of biorthogonal elegant Hermite-Gaussian (EHG) modes,the analytical expressions for the mode coherence coefficients (MCCs) and M2-factor of laser light have been derived. The relation between the coherent-mode representation of laser beams in terms of EHG modes and that in terms of corresponding standard Hermite-Gaussian (SHG) modes has been built up. Furthermore,two typical application examples have been discussed. It can be shown that the MCCs in EHG coherent-mode representation can be obtained by use of the MCCs in SHG coherent-mode representation;for the case of the modes with the same orders having the same weight factors,the beam quality of the laser beams that are made up of a superposition of mutually uncorrelated EHG modes is better than that of mutually uncorrelated SHG modes.