全息光栅拼接系统中的像差补偿法

Compensational Method for Aberration in Mosaic System of Holographic Grating

全息光栅拼接参数需要用参考干涉条纹来检测。系统像差会造成干涉条纹扭曲,产生光栅拼接误差。为补偿像差造成的光栅拼接误差,对像差与干涉条纹扭曲量之间的理论关系进行了研究,利用计算机模拟了参考干涉条纹图像,并将光栅拼接误差预调制到参考干涉条纹图像中。为验证该方法的有效性,在曝光系统像差峰-峰值为0.72λ的情况下进行了光栅拼接实验,在光栅拼缝处像差造成-1级衍射波面最大突变量为0.36λ。利用预制参考干涉条纹图像作为拼接参考时,其最大突变量为0.097λ。实验结果表明,在曝光系统像差较大的情况下,干涉条纹预制法能够有效地控制光栅拼接误差。

The reference interference fringe is used to detect the parameters of the holographic grating.The distortion of the interference fringes is caused by the system aberration,and the grating tiling-error is generated.In order to compensate the grating tiling-error,the relationship between the aberration and the distortion of interference fringe is studied.The reference interference fringes are simulated by computer,and the grating tilingerror is per-modulated into the interference fringe image.To verify the effectiveness of the proposed method,the grating splicing experiment is carried out under the condition of system aberration whose peak to peak value is0.72λ.The maximum variation of the-1st diffraction wave front at the grating seam is 0.36λ.When the prefabricated reference interference fringe images are used as the reference,and the maximum variation is 0.097λ.The experimental results show that the modulated interference fringes can effectively control the tiling-error of the grating in the exposure system with large aberration.