High refractive index contrast in a photosensitive polymer and waveguide photo-printing demonstration

Abstract

In this paper, the realisation and performances of a photo-printed waveguide in an intrinsically photosensitive polymer film have been demonstrated. One of the advantages of this technique, is the reduced number of process steps. In this polymer (polyvinylcinnamate), local UV irradiation yields a lowering of refractive index. Using this polymer, the photo-induced index contrast in a film is significantly improved from 1.5 × 10 −2 (previous works) up to 2.5 × 10 −2 at 1550 nm. This is one of the highest contrast value reported for a photo-printed non-birefringent waveguide. Concerning optical transmission properties, first promising results have been obtained. Optical measurements in the polymer film (0.25 dB/cm at 1550 nm) and in polymer solution (less than 0.2 dB/cm at telecommunication wavelengths) have shown the high potentiality of this material.