POLYMER-BASED WAVE-GUIDES AND OPTICAL SWITCHING

The fabrication and linear optical characterization of a Bragg reflect or in a planar polymeric waveguide, suitable for an all-optical switch ing device, is reported. Surface corrugation gratings with a grating c onstant of 339 nm were produced in different polymeric films of poly(p henylene-vinylene), polydiacetylene and polystyrene by excimer laser p hotoablation. Furthermore, the gap in the linear transmission spectrum of the modulated waveguide was measured and compared with the result of numerical simulations. A good agreement can only be found if a non- uniform grating with a small chirp is assumed. This small deviation fr om the uniform grating cannot be resolved with a scanning electron mic roscope. However, this linear optical investigation helps to further i mprove the fabrication process and opens the possibility to yield a we ll-defined grating with a prescribed modulation strength, which is a v ital requirement for the proper operation of a nonlinear all-optical s witch. (C) 1998 Elsevier Science B.V.