Digital quasi-phase-matched two-color nonvolatile holographic storage

Unwanted erasure during readout of holographic data can be reduced or eliminated by use of a different wavelength for reading than that which was used for writing. To prevent distortion and Bragg mismatch that would be unacceptable for digital data storage, one can format data to account for the wavelength difference. Techniques to format data and the results of this formatting are presented. Varying the formatting parameters is investigated to optimize diffraction efficiency.