Low-drive-voltage, low-loss AlGaAs/GaAs 2*2 switch

The letter reports the realisation of a 2 × 2 switch using a Mach-Zehnder interferometer with tunable coupler sections. The structure is based on a GaAs-AlGaAs double heterostructure with SnO2-doped In2O3 electrodes. At a wavelength of 1.15 μm, this device is characterised by a low switching voltage of 7.5 V and a low loss of 4 dB/cm. A high extinction ratio of 20 dB can be achieved.