High birefringence control and polarization insensitive Bragg grating fabricated in PECVD planar waveguide with UV polarized irradiation

A method for rapid compensation of high intrinsic birefringence in plasma-enhanced chemical vapor deposition (PECVD) based planar waveguides is presented. The intrinsic waveguide birefringence is compensated by a large UV induced opposite birefringence generated with polarized UV ArF excimer laser irradiation (oriented normal to the waveguide axis) and enhanced further through hydrogen loading. The fabrication of polarization insensitive Bragg gratings in PECVD planar waveguides with a large intrinsic birefringence of 6.3 × 10−4 is demonstrated by trimming it to zero birefringence with a low fluence blanket UV polarized exposure. After annealing for removal of the hydrogen, the polarization insensitive nature of the Bragg grating is unchanged.