Investigation of refractive index modifications in CW CO 2 laser written planar optical waveguides

Abstract

This paper presents the measurement of the refractive index profile of buried channel waveguides fabricated by a CW CO 2 direct writing technique. A reflectance method is used to assess the refractive index distribution n( x,y) in these structures as it is a key parameter determining the propagation properties of guided wave devices. Beam propagation method (BMP) is used with experimentally determined cross-sectional data and refractive index profile to model the waveguides. The spatial resolution is 1.3 μm and, 5.10 −4 for the refractive index.