衍射光学束匀滑器件的自相关系数与性能参数

Autocorrelation Coefficient and Performance Parameter of Diffractive Optical Element for Beam Smoothing

根据衍射光学束匀滑器件透过率函数的自相关系数,重新定义了表征衍射光学器件(DOE)焦面光强分布束匀滑性能的两个参数:光能利用率和顶部不均匀性。此种定义是对利用衍射光学器件焦面光强分布的空间频谱进行的性能参数定义的一种近似,对于精细化设计,两种定义计算结果非常吻合;而对于传统设计,两种定义计算结果有较大偏差。当衍射光学束匀滑器件与光谱色散平滑(SSD)技术联合使用时,模拟计算结果表明,对于精细化设计与传统设计,定义的性能参数均能反映衍射光学器件的实际使用性能。

Based on the autocorrelation coefficient of the transmittance function of the diffractive optical element (DOE) for beam smoothing, two performance parameters, light efficiency and top non-uniformity, are re-defined. This definition is a kind of approximation of that defined by the spatial frequency spectra of the far filed intensity distribution of the DOE for beam smoothing. The simulated results calculated with two definitions are almost same for the precise designed DOE, but different for the traditional designed DOE. When smoothing by spectral dispersion (SSD) is used with the DOE to realize beam smoothing, the simulated results show that the definition in this paper can reflect the practical performance of the DOE for beam smoothing, no matter whether the DOE for beam smoothing is designed with the precise design method or the traditional design method.