EXPLORING THE LIMITS OF OPTICAL STORAGE USING PERSISTENT SPECTRAL HOLE-BURNING - HOLOGRAPHIC RECORDING OF 12,000 IMAGES

The storage of 12 000 intensity patterns in a dye-doped polymer film h as been achieved using persistent spectral hole-burning in combination with image plane holography. A limit of storage density in this class of materials given by the intrinsic frequency selectivity is reached. For the first time, we used an experimental procedure where we maximi zed and distinguished different sources for signal deterioration which are relevant at large storage numbers. We identify the two major effe cts that are responsible for the reduction of the image quality: first ly, the contribution of vibronic levels in the matrix which gives rise to accumulating background due to nonresonant absorption and, secondl y, the influence of light-induced spectral diffusion leading to signal weakening of previously written information. These issues have to be taken into account for practical applications of holography in frequen cy selective materials.