计算全息图的高效编码方法  

Efficient Encoding Method for Computer-Generated Hologram

作　　者：李春琦 黄启泰 任建锋[1,2,3,4] Li chunqi;Huang Qitai;Ren Jianfeng(School of Optoelectronic Science and Engineering,Soochow University,Suzhou 215006,Jiangsu,China;Collaborative Innovation Center of Suzhou Nano Science and Technology,Soochow University,Suzhou 215006,Jiangsu,China;Key Laboratory of Advanced Optical Manufacturing Technologies of Jiangsu Province,Soochow University,Suzhou 215006,Jiangsu,China;Key Laboratory of Modern Optical Technologies of Education Ministry of China,Soochow University,Suzhou 215006,Jiangsu,China)

机构地区：[1]苏州大学光电科学与工程学院,江苏苏州215006 [2]苏州大学苏州纳米科技协同创新中心,江苏苏州215006 [3]苏州大学江苏省先进光学制造技术重点实验室,江苏苏州215006 [4]苏州大学教育部现代光学技术重点实验室,江苏苏州215006

出　　处：《激光与光电子学进展》2024年第8期83-88,共6页Laser & Optoelectronics Progress

摘　　要：利用计算全息图(CGH)能够实现对非球面面形的高精度检测。为了提高CGH的编码效率,提出一种以圆弧为基元对刻线条纹进行分段描述的编码方法,该方法将编码过程分为二值化编码和曲线描述两个步骤。二值化编码采用牛顿迭代法将相位等高分界线离散化;曲线描述结合二分法及残余误差均方根最小准则,利用圆弧对条纹离散点进行编码计算,从而得到刻线条纹。针对一离轴非球面,进行了CGH的设计、编码与制作,在编码精度优于λ/1000的前提下,运算时间仅需3 h,编码文件仅为39 MB,刻蚀时长仅需40 min,证明所提方法相对于传统编码方法能够大幅度提高编码效率,且误差分析表明CGH的波前root-sum square(RSS)误差仅为0.00255λ,证明所提编码方法高效可行。A computergenerated hologram(CGH)can be used to detect an aspheric surface with high accuracy.To enhance the encoding efficiency of the CGH,this paper proposes an encoding method for the segmented description of engraved stripes with a circular arc as the primitive,dividing the encoding process into two steps:binary encoding and curve description.The binary encoding employs the Newtonian iteration method to discretize the phase contour dividing line.The curve description combines the dichotomy and the minimum rootmeansquare criterion of the residual error.Furthermore,by leveraging the circular arc to encode the discrete points of the engraved stripes,the engraved stripes are obtained.In this paper,the CGH is designed,encoded,and generated for an offaxis aspheric surface.To obtain an encoding accuracy higher thanλ/1000,the operation time is only 3 h,the encoded file is only 39 MB,and the etching time is only 40 min.This demonstrates that the proposed method can considerably enhance the encoding efficiency compared with the traditional encoding method.Error analysis suggests that the wavefront rootsum square(RSS)error of the CGH is only 0.00255λ,demonstrating that the proposed encoding method is efficient and feasible.

关 键 词：计算全息图 编码计算 圆弧 刻线条纹 

分 类 号：O438.1[机械工程—光学工程]