SiGe/Si Mach–Zehnder interferometer modulator based on the plasma dispersion effect

A SiGe Mach–Zehnder interferometer modulator based on the plasma dispersion effect has been fabricated. A maximum modulation depth of 86% and a switching current of 40 mA with a π-phase-shift voltage of 0.9 V have been achieved at 1.3 μm wavelength. The device has a measured insertion loss of 2.5 dB and a response time of 238 ns.