Half-tone optical storage in a-Si films

Bleaching of amorphous silicon films by local heating with a focused laser beam was found to provide a promising optical storage method useful in the fabrication of half-tone optical masks needed in the fabrication of optical diffraction components. A study was made of changes in the optical properties and the structure of a-Si films occurring under the influence of laser radiation. A spatial resolution up to 2000 lines/mm was achieved. A mechanism explaining the experimental results was developed.