Polymer thin films containing azo dye for rewritable media

The writing and erasing properties of azo-dye-doped polymer thin films at a blue wavelength were investigated. The optically induced birefringence in the polymer film due to a linearly polarized light can be utilized for digi tal optical data storage. The dependence of the contrast of a stored patter n on temperature was examined to estimate the thermal stability of the poly mer films. Bits could be written and erased by irradiation of the linearly and circularly polarized laser beam, respectively.