Patent ID: 6118560
Filing Date: 2000-09-12
Classification: G03H,G11C

Abstract:
A hologram-write method for mitigating detection scatter noise in holographic storage systems by determining orientations of scatter noise vectors before writing hologram data into a holographic storage medium, the method comprising the steps of:a) outputting a first input test image, from a data input device having an array of pixels, into the holographic storage medium;b) storing the first input test image in the holographic storage medium as a set of first gratings, each of the first gratings corresponding to a pixel in the data input device;c) reading out the stored first input test image from the holographic storage medium as a first output test image, the first output test image being derived from the first input test image and a random scatter noise within the holographic storage medium;d) recording the first output test image;e) outputting a second input test image, from the data input device, into the holographic storage medium;f) storing the second input test image shifted in phase to the first input test image in the holographic storage medium as a set of second gratings, each of the second gratings corresponding to the pixel in the data input device;g) reading out the stored second input test image from the holographic storage medium as a second output test image, the second output test image being derived from the second input test image and the random scatter noise within the holographic storage medium;h) recording the second output test image;i) determining an orientation of a scatter noise vector in the holographic storage medium, from recorded values of the first and the second output test images;j) outputting final hologram data modulated by the orientation of the scatter noise vector, from the data input device, into the holographic storage medium; andk) storing the final hologram data in the holographic storage medium as a set of final gratings, thereby resulting in reducing detection scatter noise at a subsequent hologram readout.