Measurement of the birefringence of UV-written channel silica waveguides by magnetooptic polarization-mode coupling

We report the measurement of the birefringence in integrated-optical waveguides using magnetooptical coupling between the two principal polarizations of the fundamental mode. We demonstrate this measurement technique for directly ultraviolet (UV)-written channel waveguides in silica on-silicon and silica-on-silica. The dependence of the waveguide birefringence on the UV-writing power and UV polarization is investigated. The results are compared with the birefringence of etched waveguides in comparable material systems. An analytical formula for the form birefringence in buried channel waveguides is developed, and measured data are compared with theoretical results.