| 摘要 |
This invention describes a novel coding and implementation techniques for high-speed high-density optical disk data storage. Multiple narrowband spectral beams, either coherent or non-coherent, are combined together by optical fiber couplers or lenses assembly and are then focused into a photosensitive film with diffraction limited spot size through a specially designed hybrid diffractive/refractive lens with extended depth of focus, so that the beam size remains diffraction limited size in the whole depth of the recording medium volume. Multiple reflection gratings which are respectively corresponding to these used spectral bands are recorded in the medium through interferences between the incident beams and the reflected beams from a reflection mirror which is attached at the back surface of the recording film. The reflected beam from the reflection mirror can also be replaced by a second focused beam (without using reflection mirror) with the beam splitted using an optical fiber splitter from the incident recording beam and using an identical lens with the same extended depth of focus property. By using white light to readout these gratings, using a spectrometer or multi-wavelength reader to acquire the reflected light, and using algorithms to analyze the spectrum, the recording information is recovered.
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