PHASE MASK FOR HOLOGRAPHIC DATA STORAGE

摘要

A phase mask for holographic data storage is provided to improve the intensity distribution of beam on the Fourier plane of a holographic storage system through plural phase cells having sub-cell scale phase shift. A phase mask(3) for holographic data storage includes phase cells(4) having sub-cell scale phase shift in order to perform recording and/or reading on a holographic storage medium. The size of the phase cell is equal to the size of the phase cell is same as those of the integral multiple of the pixel size of the spatial light modulator, and different in the in-plane vertical direction of the phase mask.