Strong photosensitivity in tin-doped silica films

摘要

The observation is reported of a strong negative change in the refractive index of tin-doped thin silica films deposited by helicon activated reactive evaporation. Samples with concentrations between 5 and 25 mol% SnO/sub 2/ were exposed to 2 kJ/cm/sup 2/ of 248 nm UV radiation. Negative refractive index changes as large as -2.7/spl times/10/sup -3/ were observed on irradiation.