Photosensitive effects distinguished as type I and type IIA photosensitivity within optical fibers were observed in a much more pronounced form within germanosilica waveguides deposited by hollow-cathode plasma-enhanced chemical-vapor deposition. With increasing exposure to 193-nm UV light, positive index changes greater than 2 × 10<sup>-3</sup> were observed, followed by negative index changes greater than -5 × 10<sup>-3</sup> . These behaviors are attributed to an increase in macroscopic polarizability and a reduction in material density, respectively. The negative index change is more temperature resistant and is fully annealed only at 900 °C, whereas the positive one is annealed at 500 °C.
© 1998 Optical Society of America
(230.7390) Optical devices : Waveguides, planar
M. V. Bazylenko, D. Moss, and J. Canning, "Complex photosensitivity observed in germanosilica planar waveguides," Opt. Lett. 23, 697-699 (1998)