基于槽形函数拟合的刻划光栅衍射特性分析方法

作为对光栅刻划工艺的理论指导，提出了一种基于槽形函数拟合的机械刻划光栅衍射特性分析方法，解决了高刻线密度光栅衍射效率测量值与理论值偏差较大的问题.以刻线密度为1200l/mm的紫外光栅为例，对光栅主截面上的实际槽形纵横坐标扫描取值，进而拟合出槽形函数，经理论计算找到了导致衍射效率偏低的原因，并通过改进工艺，使光栅衍射效率提高了约20%. 关键词： 刻划光栅 槽形函数拟合 衍射特性 分析方法

Analytical method of the diffraction characteristic of ruled grating based on profile fitting function

The diamond stylus extrudes the metal film and causes coupled elastic-plastic deformation which shapes the profile of the ruled grating.The grating profile function which is hard to get would influenced accurate analysis of the diffraction characteristic.An analytical method of the diffraction characteristic of the mechanically ruled grating is presented based on the profile fitting function.The problem of excessive departure between the measured and theoretical value of the diffraction efficiency of high density ruled grating is solved by this method.We take a 1200l/mm UV grating,the grating profile is scanned in the principal section and then the profile curve function is got.The reason why the diffraction efficiency wasn't high is found by calculation.And then the diffraction efficiency increased about 20% by improving the technology.