Research on encoding multi-gray-scale phase hologram and wavefront reconstruction

摘要

Application of computer-generated holography for wavefront generation is beneficial for optical interferometry and 3D image display. However, there is a noticeable encoding error in computer-generated holograms, which is encoded by using the object's wavefront function in a computer. The encoding error will be transmitted and amplified during fabrication of a hologram, which can cause a reconstructed error in the generated wavefront. A correction method of encoding errors based on the least-squares fitting is proposed. A validating experiment is completed by using a liquid crystal spatial light modulator to reconstruct a group of paraboloid wavefronts. The results show that encoding errors increase the reconstructed error of a wavefront less than optical system errors, and the root-mean-square value drops 0.022 lambda after the correction of the encoding error, but it falls 0.092 lambda after the correction of optical system errors. The total error has been reduced by 0.114 lambda. This research is helpful for prediction of encoding errors and improvement of wavefront reconstruction accuracy. (C) 2016 Optical Society of America