PHOTOREVERSIBLE BIREFRINGENCE IN DOPED VYCOR GLASS

Photoreversible birefringence is demonstrated in Vycor glass, doped wi th nanocrystalline ZnS and Cu, by linearly polarized 266-nm pulsed exc itation. The birefringence is readily reversed by exposure to orthogon ally polarized UV radiation. Photoinduced birefringence is stable at r oom temperature and can be removed by annealing at temperatures above 250 degrees C.