Polarisation insensitive wavelength multiplexers using stress release grooves

A new method for compensating polarisation sensitivity of arrayed waveguide gratings based on SiO/sub 2/ using stress release grooves has successfully been applied. Performance of the device is not deteriorated by using this method. The method presented here using stress release grooves consists of a suitable arrangement of stress release grooves in the waveguide array. We achieved full polarisation insensitivity for (AWG) arrayed waveguide grating multiplexers by using this method while observing no degradation in performance after processing. This method for birefringence compensation has been proposed for a polarisation-insensitive Mach-Zehnder interferometer.