Modified coupled-wave equations are used to calculate the effect of grating shape on coupling coefficient of the second-ordergratings.
利用改进的耦合波理论计算了具体器件结构中光栅形貌对二级光栅耦合系数的影响。
2
It is also shown that only when the gratings are cylinder or plane ones, the secondorder sagittal anastigmatic circular field and meridional non defocus flat field spectral images can be formed.