High-Speed Carrier-Injection-Based Polarization Controller with InGaAlAs/InAlAs Multiple-Quantum Wells

We demonstrate a waveguide-based polarization controller that monolithically incorporates an active InGaAlAs/ InAlAs multiple-quantum-well phase shifter and a passive half-ridge polarization converter on InP. The butt-joint active/passive integration technique and self-aligned waveguide fabrication steps are employed. Using the fabricated device, efficient rotation of the Stokes vector over π radian is obtained on the Poincare sphere by injecting 14-mA current to a 1.4-mm-long phase shifter. Dynamic response time below 5 ns is also confirmed, demonstrating the feasibility of low-power high-speed integrated polarization controller on InP.