Method to balance and stabilize interferometric waveguide devices

The performance of fiber optic and planar waveguide interferometric devices can be degraded by path length errors. These imbalances can occur during device fabrication, during the inscription of gratings into these devices, or during device stabilization. Correction of these errors by ultraviolet exposure is typically performed prior to annealing and is thus not stable. We present a post-annealing process to correct for fabrication errors and create stable devices. Results obtained for a fiber Mach-Zehnder add-drop are presented.