Silicon double-injection electro-optic modulator with insulated-gate and

Abstract

A double-injection transistor structure with an MOS gate is utilized as a guided-wave electro-optic phase modulator at infrared wavelengths in a silicon-on-insulator (SOI) waveguide. Cathode, gate and anode regions are integrated in the waveguide, longitudinally. The effective phase modulation is given by the voltage-variable overlap of the guided-mode optical field with carrier-induced local changes in the silicon refractive index. An electron-hole plasma is injected under the gate by cathode and anode. Using depletion-layer widening, the plasma channel width and mode overlap are controlled very rapidly by one or two low-power gate electrodes.