First- and second-order Bragg gratings in single-mode planar waveguides of chalcogenide glasses

First- and second order Bragg reflectors at telecommunication wavelength (1.5 /spl mu/m) were fabricated in single-mode monolayer (As/sub 2/S/sub 3/) and multilayer (AsSSe-AsS) chalcogenide glass (ChG) planar waveguides with near bandgap illumination using an interferometric technique. Reflectivities as high as 90% near 1555 nm, and index modulations up to 3/spl times/10/sup -4/ were achieved. The volume photodarkening effect is the principal mechanism involved in the formation of the Bragg gratings.