Homodyne Detection of Data Pages in Lippmann "Holographic" Memories
Abstract
Lippmann interference architectures are alternatives to holographic memories for high capacity data storage. In these systems, the image beam carrying the information data interferes with its reflection onto a mirror. The resulting interference pattern thus records a grating in the light sensitive material. Several images can be wavelength multiplexed at the same location. On the one side, and just as in holography, the number of images multiplexed in the same location is given by the wavelength Bragg selectivity of the thick gratings and is thus inversely proportional to the material thickness. On the other side, the page resolution is just diffraction limited and does not depend on this thickness. Each page can thus have a very large data content. Conversely to holography, no additional reference beam is required for recording. This absence of any reference beam simplifies the recording architecture at the expense on stringent requirements on the set-up adjustments. However, the potential numerous advantages of the Lippmann architectures seem to justify these constraints. One of these advantages is the possibility to easily implement an homodyne detection that greatly enhances the detected signals. Such homodyne detection of data pages is presented and discussed here for the first time.
Domains
Optics [physics.optics]| Origin | Files produced by the author(s) |
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