Ion-exchanged glass waveguide Mach-Zehnder interferometers for wavelength multi/demultiplexing and the effect of thermal post-annealing on spectral transmission

A non-symmetric three-port integrated optical Mach-Zehnder interferometer configuration is employed to make 1.3/1.55 mu m and 1.48/1.55 mu m wavelength multiplexers/demultiplexers. The devices are produced by a potassium-silver double-ion exchange process. The effect of thermal post-annealing on the spectral behaviour of the fabricated devices is investigated. It is observed that the spectral transmission of the 1.3/1.55 mu m device is not sensitive to post-annealing while the transmission spectrum of the 1.48/1.55 mu m device changes after post-annealing. The losses and extinction ratios of the fabricated devices are also determined.