Low Driving Voltage 40 Gbit/s n-i-n Mach-Zehnder Modulator Fabricated on InP Substrate

We have developed a traveling-wave optical modulator using an n-i-n heterostructure fabricated on an InP substrate. The modulation characteristics are studied theoretically and experimentally. We obtained an extremely small n voltage (V π ) of 2.2 V, even for a short signal-electrode length of 3 mm. We confirmed a wide frequency bandwidth and clearly open eye diagrams at 40 Gbit/s.