Asymmetric Mach-Zehnder Demultiplexers In GaAs/GaAIAs Single And Double Heterostructures

We report on guided-wave periodic filters fabricated on a semiconductor substrate. The devices, based on an asymmetric Mach-Zehnder interferometer, operate with a channel separation of 19nm in the 1500nm wavelength range. An extinction ratio of 18dB has been measured in a double heterostructure device designed for TE polarized light. Operation with reduced polarization dependence is also demonstrated in a single heterostructure device with extinction ratios of 24.1dB and 22.5dB for TE and TM polarization, respectively.