用于合成全息图拍摄的相位散射片的设计

Design of Phase Diffuser for Synthetic Hologram

摘要:

介绍了合成全息图拍摄过程中图像的滤波处理过程,并分析了利用透镜对图像信息进行会聚时光场的不均匀性问题。为改善会聚光场的均匀性,通常需在透镜前设置弱散射片,从理论上分析了相位散射片改善光场均匀性的原理,基于该原理利用傅里叶迭代算法(G-S算法)对相位散射片的相位分布进行了设计,并将所设计的相位片应用于实际图像进行了仿真分析。结果表明,通过精确设计相位片的相位分布能极大地改善光场的均匀性,且能在一定范围调整光斑尺寸的大小。最后针对相位片实际制作中相位的量化问题分析了量化误差的影响,仿真结果表明,当量化阶数达到8阶时量化误差的影响可以忽略。 更多还原

Abstract:

Described are the image filtering and processing during making a synthetic hologram, and analysed is the nonuniform field of the converging light by optical lens. To improve the uniformity of the converged field, a weak diffuser is often inserted before the lens. It is explained why the phase diffuser can improve the field’s uniformity theoretically. Based on the theory, we designed the phase distribution of the phase diffuser was designed based on G-S algorthm and simulations were performed by attaching the phase distribution to a real image. The results show that the uniformity of the field can be greatly improved by the designed phase diffuser, and the plot size can even be adjusted in a certain scope. We finally discussed the influence when quatized the phase by different grades, and simulation results show when quantization grade reached eight the quantization error can be ignored.