Effect of boundary on refractive index of PDMS

Abstract

In this contribution we present some results of a study of a refractive index inhomogeneity near the boundary of polydimethylsiloxane (PDMS) samples. We have observed inhomogeneities of the refractive index at PDMS–glass, PDMS–brass, PDMS–Teflon, PDMS–polystyrene and PDMS–PDMS boundaries. The greatest changes of the refractive index were observed at the PDMS–PDMS boundary where an increase of the refractive index in a narrow region close to the boundary was observed. It gives the possibility for guiding light. The existence of such a waveguide was proved by the fact that the boundary also guided light when samples containing PDMS–PDMS boundaries had been bent.