基于任意相移量的4步相移数字全息新方法  

A new method of four-step phase-shifting digital holography based on arbitrary phase shifts

作　　者：余清婷[1] 吕晓旭[1] 张庆生[1] 刘赣勇[1] 

机构地区：[1]华南师范大学信息光电子科技学院,广州510006

出　　处：《激光技术》2009年第4期409-412,共4页Laser Technology

基　　金：国家自然科学基金资助项目(60747001;60877070)

摘　　要：为了研究相移数字全息中的相移量计算问题,从菲涅耳衍射和全息理论出发,对相移离轴无透镜傅里叶变换数字全息的记录和再现进行了分析,推导了基于任意相移量的4步相移数字全息图的光场表达式,提出了一种利用相位相减计算任意相移量的新方法,并进行了相应的实验验证,得到了预期效果。结果表明,该方法与传统的4步相移方法相比,不需要对相移器进行严格标定,也能有效地消除数字全息再现光场中的0级衍射和共轭像,提高再现像的信噪比,因此,这对降低测量系统的复杂性,促进4步相移数字全息的发展是有帮助的。In order to study the problem of calculating phase shifts in the phase-shifting digital holography, the recording and reconstructing principle of phase-shifting off-axis lenless Fourier transform digital holography was analyzed based on the Fresnel diffraction and holographic theory. Then the complex field expression of four-step phase-shifting digital hologram based on arbitrary phase shifts was deduced. A new method was proposed to calculate arbitrary phase shifts by means of phase subtraction. The experimental results show that compared with the conventional method of four-step phase-shifting, it is not necessary to calibrate phase-shifting devices strictly with this method. The zero-order diffraction and the conjugate image are also eliminated effectively and the ratio of signal to noise is similarly improved. Therefore, the method contributes to the reduction of the complicacy of the measure system and the promotion of the development of four-step phase-shifting digital hologram.

关 键 词：全息 数字全息 相位相减 相移技术 傅里叶变换 

分 类 号：O438.1[机械工程—光学工程]