透射光谱法测光栅参数的可行性

利用透射光谱,结合正单纯形法来反演折射率调制光栅参数,首先利用光栅衍射傅里叶模式理论及RTCM算法得出在200nm~900nm波长范围内的透射光谱曲线,从上取5个点,作为理论计算值; 其次,在上述曲线上加入偏差不同的高斯噪声,以模拟透射光谱的测量曲线,再从每条曲线上各取5个对应点,获取模拟测量值;然后,假定光栅参数的初始值,代入评价函数,用正单纯形法不断进行迭代反演,得到光栅参数的计算模拟结果。此方法简单、快速、精确。

The feasibility of measuring grating parameters with the transmission spectrum method

A new method,transmission spectrum method combined t he normal simplex algorithm,is proposed to measure the grating parameters.Firstly ,the transmission spectrum of the range from 200nm~900nm is obtained according to a certain grating model with the Fourier model method and reflection and tran smission coefficient matrix method (RTCM),based on which the Gaussian noises wi th different standard deviations are added to it to get the simulated measuring value of transmission spectrum,then five points are gotten respectively from th e transmission spectrum with or without Gaussian noises.Secondly,the original s upposed value of grating parameters is brought to the estimating function.Throug h repeatedly computing with the normal simplex algorithm,the grating parameters are obtained.