参考光照射下的数字全息图频谱特点及应用  

Spectrum characteristics of digital holograms illuminated with reference wave and its application

作　　者：邱培镇[1] 庞涛[1] 

机构地区：[1]湖州师范学院理学院物理系,浙江湖州313000

出　　处：《光学技术》2014年第4期349-352,共4页Optical Technique

基　　金：国家自然科学基金项目(11071222);湖州师范学院2013年校级科研项目(KX21064)

摘　　要：提出了一种在离轴数字全息再现过程中确定参考光角度和简化滤波器设计过程的方法。分析了模拟参考光照射下的离轴数字全息图的频谱特点。首先将数字全息图与计算机模拟的原参考光波相乘,然后做傅里叶变换,得到其频谱图。结果发现,含有被记录物体信息的物光波频谱始终处在频谱面的中央位置。依据这一特点,不仅可以实现模拟再现时最佳参考光的角度参数测定,而且还可以使滤波器的结构设计过程简化。借助于滤波技术,数字全息再现像中零级像和共轭像得到了有效的去除,再现物体实像质量得到了有效的改善。A method is proposed to extract the angle of reference wave and simplify the process of the filter design in digital reconstruction of off-axis hologram.The spectrum characteristics of the off-axis digital holograms illuminated with reference wave are analyzed.Firstly,the digital hologram is multiplied with computer simulated reference wave.Secondly,it is used to do fast Fourier transform and the spectrum is obtained.It is found that without the extra spectra-shift process,the spectrum of the real image always appears in the center of the spectrum plane and never shifts.According to this feature,the optimal angle of the simulated reference wave is obtained,and the process of filter structure design can be simplified.Based on the filter technique,the zero-order and conjugate image in the reconstructed image of off-axis digital holography is eliminated,and the contrast and the details of the reconstructed real image are improved.The theoretical analysis and experimental results are analyzed.

关 键 词：信息光学 数字全息图 频谱 滤波器设计 参考光角度值 

分 类 号：O438[机械工程—光学工程]