DISTRIBUTED BRAGG REFLECTION IN INTEGRATED WAVE-GUIDES OF POLYMETHYLMETHACRYLATE

Distributed Bragg reflection from integrated polymethylmethacrylate wa veguides fabricated on corrugated spin-on-glass substrate is reported. Utilizing third-order Bragg resonance, a maximum reflection of 92% fr om the grating filter is measured at a wavelength of 423.6 nm. A maxim um bandwidth of the Bragg reflection is found to be similar to 0.5 nm for a 6 mm long filter, The broad bandwidth and the significant transm ission loss (similar to 90%) away from resonance are believed to be re lated to the radiation coupling by the grating. It is shown that the r adiation loss can be minimized without sacrificing high reflectivity b y limiting the waveguide length to 0.5 mm, the saturation length of th e Bragg reflector. (C) 1995 American Institute of Physics.