莫尔条纹法精确控制全息光栅光栅常数的研究

Study on precisely controlling the grating constant of holographic grating with Moire pattern method

为精确控制全息光栅的光栅常数,提高全息光栅的制作精度,提出了莫尔条纹法控制光栅常数的方法,建立光栅常数随莫尔条纹宽度变化的数学模型,分别讨论了不同莫尔条纹宽度对光栅常数的影响。通过检验莫尔条纹宽度,实现对干涉场条纹间距的检验,可以提高全息光栅光栅常数的控制精度。实验结果表明,对于制作3 600 lines/mm全息光栅,其刻线密度控制精度可以达到±0.05 lines/mm。该模型正确反映了光栅常数随莫尔条纹宽度的演化规律,采用基准光栅结合莫尔条纹精确控制全息光栅光栅常数的方法能够满足全息光栅的制作要求,为全息光栅曝光系统的设计提供理论指导和设计方法。

In order to precisely control the grating constant of holographic grating and improve the fabrication accura- cy of holographic grating, the method of controlling grating constant with Moire pattern method is proposed. A mathe- matical model is established in which the grating constant varies with Moire pattern width. The influences of different Morie pattern widths on grating constant are discussed respectively. Through testing the Moire pattern width, the test of interference fringe spacing is achieved, which can improve the control accuracy of the grating constant of holo- graphic grating. The experiment results indicate that the control accuracy of the groove density can reach ＋ O. 05 lines/mm for the 3 600 lines/mm holographic gratings. The proposed model correctly reflects the evolution law of grating constant varying with Morie pattern width. The method of precisely controlling grating constant with ref- erence grating and Moire pattern satisfies the fabrication requirement of holographic grating, which provides theoreti- cal guidance and design method for holographic grating exposure system.