四步相移数字全息中随机误差的抑制方法

Elimination of random errors in four-step phase-shifting digital holography

提出一种在四步相移数字全息中消除随机相移误差及CCD噪声的方法。通过多次重复四步相移数字全息的实验过程,使得每一步的相移都有多幅全息图像与之对应,把每一步对应的多幅全息图像进行数学平均就会得到4幅全息均值图像。理论分析表明,使用这4幅全息均值图像进行数字全息的重建,可以得到精确的物光波的分布,有效地消除随机相移误差及CCD噪声的影响。计算机模拟结果表明:该方法有助于提高数字全息重建光场质量。

A novel approach is proposed to eliminate the random phase-shifting errors and CCD noise in four-step phase-shifting digital holography. By carrying out the phase-shifting process repeatedly, a series of holograms for each phase step are obtained. Theoretical analysis indicates that the random phase-shifting errors and CCD noise can be completely removed if we substitute the single hologram with the average of multiple holograms in the reconstruction. The feasibility of this method is demon-strated by computer simulation, and the results show that this method is useful in improving the qual-ity of reconstruction in phase-shifting digital holography.