提出了利用透射光谱结合优化算法来反演衍射光栅参量的新方法。利用衍射光栅两个对称级次(m=±1)的能量比来处理这种差异,实现光栅参量的成功反演。首先,在理想光栅(以正弦面型光栅为例)透射光谱曲线上叠加高斯噪声来模拟实验测量曲线,结合正单纯形法对该法进行模拟反演,所得结果非常接近真值。其次,对于体积相位全息光栅,利用实验测得的透射光谱±1级能量比,反演得到的各参量的相对误差不超过2%,这进一步证明了该方法的可行性和有效性。同时该方法具有无损伤、操作简便、可重复、易推广、成本低等优点。

A new method for determining the grating parameters with the transmission spectrum and the optimized algorithm is described. In order to decrease the difference and ensure the precision of the calculation result, the symmetric-order efficiency ratio m=±1 is employed. Firstly, several points from the simulated experimental curve are selected, which is attained by adding the Gauss noises on the transmission spectrum, submit to the optimization methodNormal simple algorithm to calculation the optical parameters of the grating. The result is very near to the true value. Secondly, the volume phase holographic grating parameters are calculated with this metrology, the result is perfect, its relaive error is less than 2%. This demonstrated the reliability and the credibility of the metrology. It has some advantages such as no damage, facility of manipulation, repeat, easy generalized and low cost.