Characterization of the optical-functional properties of a waveguide written by an UV-laser into a planar polymer chip

The optical-functional properties of an integrated-optical strip-waveguide in a planar polymer chip are presented in this article. The waveguide was directly written into the surface of a planar polymer chip by UV-laser irradiation. The refractive index depth profile of the waveguide was examined by a two-beam-interferometric method. Also the mode field distribution and the loss rate of the waveguiding structure has been characterized. The study shows that the optical-functional properties strongly depend on the UV-irradiation parameters. Several mostly independently occurring photochemical processes competing with one another are proposed to explain the formation and shape of the refractive index distribution.