Polymer waveguides under ion implantation: optical and chemical aspects

The effects of ion implantation on the linear and nonlinear optical propert ies of polymer thin films are studied. In the first step, good quality plan ar waveguides were made in a well known photoconducting polymer, polyvinylc arbazole (PVK), which has no intrinsic nonlinear optical properties. The po lymer is deposited by spin-coating onto a BK7 glass substrate. A diffractio n grating, etched on the substrate surface, acts as an input coupler for th e waveguide. We present our results from the study of these polymer wavegui des, following exposure to an energetic ion beam. The grating coupler metho d was used to characterize the linear and nonlinear optical properties of t he waveguides before and after ion implantation. Due to the conjugated chai ns created by the implantation, we expect chi((3)) type nonlinear propertie s and more specifically, an electronic nonlinear refractive index. The impl anted polymer films are characterized by infrared and UV/visible spectrosco py to study structural modifications. The new structures created and the si gnificant damage caused by the implantation are discussed. (C) 1999 Elsevie r Science B.V. All rights reserved.