Temperature dependence of Bragg reflectors in chalcogenide As2S3 glass slab waveguides

The temperature dependence of the spectral response of Bragg grating filter s at 1550 nm, written in single-mode planar waveguides of As2S3 chalcogenid e glasses, is presented. It was found that Bragg reflectance increases with temperature (corresponding to an increase as high as 4 dB of the transmiss ion depth, from 20 degrees C to 50 degrees C), whereas the resonant wavelen gth shifts by similar to 1 nm. The difference between temperature dependenc e of the structural properties for exposed and unexposed areas is thought t o be responsible for the increase of refractive-index modulation depth. Two experimental techniques are used to further study the observed phenomena. (C) 2000 Optical Society of America [S0740-3224(00)01508-3] OCIS codes: 230 .1480, 160.2750, 230.7400, 050.7330, 120.6780.