Low-voltage, high extinction ratio carrier-depletion Mach-Zehnder silicon optical modulator

As a result of the low modulation efficiency of carrier-depletion Mach-Zehnder silicon optical modulator, it always needs a high voltage around6 V, which is very difficult to supply in an integrated high-speed CMOS chip. We demonstrate a carrier-depletion Mach-Zehnder silicon optical modulator which works at a low voltage. Its coplanar waveguide electrode is carefully designed to make sure the electrical wave loss along the device is low. The device operates well at a data rate of12.5 Gb/s, whose phase-shifter length is2 mm. Voltages with the swinging amplitudes being1 V and2 V are applied to the device with the reverse bias voltages of0.5 V and0.8 V. The extinction ratios are7.67 and12.79 dB respectively.?2011 SPIE-OSA-IEEE