同轴相移数字全息中相移角的选取及相移误差的消除

基于两步同轴相移数字全息,首先从理论上分析了记录时不同相移角的选取及相移误差对再现像的影响,并给出了一种利用再现像所有抽样点的强度偏差之和作为评价标准,通过逐步改变理论设定相移角值来寻找实际相移角的相移误差消除新方法;其次对二步相移数字全息中记录时参考光波最佳相移角的选取作了计算机模拟,发现只有将参考光波的相移角选择在一定范围内,再现像的噪声较小;最后利用计算机模拟了相移误差消除,验证了所提方法的可行性.

Phase-shifting Angle Choice and Phase-shifting Error Elimination in In-line Phase-shifting Digital Holography

The influence caused by different phase-shifting a ngle of reference wave in recording and the phase-shifting error on the quality of the reconstructed image is investigated in two-step phase-shifting in-line digital holography, and an effective method of eliminating the phase-shifting error is presented, in which the summation of the intensity bit errors of the reconstructed image is taken as an evaluation function for an iterative algorithm to find the exact phase-shifting value. Then the optimal choice of the phase-shifting value of reference wave is simulated by computers. The simulation results show that the reconstructed image noise is weak when the phase-shifting value is in a certain range. At last, the feasibility of the method of eliminating the phase-shifting error is demonstrated by computer simulation also.