基于广义相移干涉术的数字全息实验

Experiment of Digital Holography Based on Generalized Phase-Shifting Interferometry

设计了一种基于广义相移干涉术的数字全息实验装置,介绍了相应工作原理。为了大幅减少精密相移器造成的相移数字全息实验成本,实验装置省去了相移器这一昂贵器件。实验利用光学器件的微小振动特点,进行相移数字全息的记录,使用两步广义相移干涉算法从干涉图中直接抽取实验中的实际相移量,代入相应物光波前再现公式计算物光复振幅,经过逆菲涅尔衍射进一步得到原始物像。实验结果表明,该装置无需相移器即可实现相移数字全息记录和再现,能够自动抽取相移值,高质量完成物光成像。该实验改进了相移数字全息的实验装置,大幅度减少了实验成本和操作难度,有利于推广和利用。

An experimental setup for digital holography was developed based on the technology of generalized phaseshifting interferometry and the corresponding principle was introduced. To decrease the experimental cost of phaseshifting digital holography caused by expensive phase shifter, this setup is designed to work without phase shifter. The recording process of phase-shifting digital holography can be realized by using the small vibration of optical device and with the algorithm for two-step generalized phase-shifting interferometry the real phase shift can be extracted and the object wave is calculated by the corresponding reconstructive formula. The image of original object can be achieved by inverse Fresnel transform. The experimental results show that this setup can work to complete the recording and reconstruction of phase-shifting digital holography without the phase shifter, extract the phase shift value automatically, and reconstnlct the image with high quality. This experiment can improve the setup of phase-shifting holography and decrease the experimental cost and the difficulty of operation, which is good for popularization and application.