Mach Zehnder interferometer optical switch using phase-change material

We report a small, self-holding 2×2 Mach Zehnder Interferometer (MZI) type optical switch by depositing a thin film of low-loss GeTe phase-change material (PCM) on both arms of the MZI. The loss and crosstalk in cross state were 0.5 dB and -34 dB and in the bar state 3.45 dB and -10.3 dB respectively. Extinction ratio of more than 13 dB and 31 dB is obtained in the cross and bar states respectively. The proposed switch has operating wavelength range of 80 nm.