HIGHLY EFFICIENT COUPLING SEMICONDUCTOR SPOT-SIZE CONVERTER WITH AN INP/INAIAS MULTIPLE-QUANTUM-WELL CORE

摘要

A highly efficient spot-size converter (SSC) that uses a fiber-coupling tapered semiconductor waveguide is demonstrated. The waveguide core of this device consists of InGaAsP for semiconductor chip coupling and an InP/InAlAs multiple quantum well (MQW) for single-mode fiber (SMF) coupling. The equivalent refractive index of the MQW core is adjusted by controlling the well-to-barrier-layer thickness ratio to expand the chip spot size to that of SMF's. A high coupling efficiency of 1.4 dB can be obtained, and the lateral and axial misalignment tolerances for the SSC are 3 times better than those for conventional semiconductor waveguides. Moreover, this device has high reproducibility because of large fabrication tolerances. [References: 22]