Abstract
A technique for the phase and amplitude detection of object beams with multivalued phase and amplitude modulation is proposed for holographic storage systems. Generally, the spatial distribution of the complex amplitude of the object beam can be precisely detected by phase-shifting interferometric measurements in which the phase of the reference wave for interferometry is temporally or spatially changed in the datapage retrieval process. On the other hand, our technique allows fast, accurate, and feasible phase and amplitude demodulations by preliminary embedding phase shift into the phase signal of the datapage during recording. This technique will significantly improve the data transfer rate and vibration tolerance of the holographic storage system because the complex amplitudes of the object beam carrying datapages can be detected by single-shot image capturing. The optical system for datapage replay will also be simplified because there is no need to use any phase-shifting device during data retrieval. The single-shot detection of the phase-modulated datapage is experimentally demonstrated.