临界周期 meaning in English

critical period

Through the analysis , it is shown that the critical periodic point as a function of refractive index is very important to fabricate the antireflective subwavelength grating
同时证明，临界周期点随折射率的变化规律在亚波长抗反射光栅的制作中有重要的作用。
Through the analysis , it is shown that : 1 , while fabricating the grating , the principle of selecting the parameters is : the period should be as large as possible , the etching depth should be small and filling factor should approach to 0 . 25 . 2 , if selecting the parameter combine the selecting principle and the requirement of concrete application , the space of selecting the parameter should be larger than before . 3 , while the period to . 4a , , the surface profile has no effect on the reflectivity
通过分析发现： 1 、在制作有一定特性的光栅时，光栅参数的选择原则为：周期的取值应尽量的大，刻蚀深度的取值应尽量的小，占空比的取值应尽量靠近f = 0 . 25 ； 2 、以参数的选择原则结合制作的具体应用要求宋选择光栅的参数，则各个参数的优化空间更大； 3 、当光栅的周期t 0 . 4时，表面面形对反射率没有影响； 4 、运用临界周期点随折射率的变化规律，可以避免由于选择光栅周期过大而出现一级衍射，从而导致制作失败。