UC Santa Barbara

We present the design and fabrication of a novel laser structure, the hybrid silicon evanescent laser. This structure utilizes offset AlGaInAs quantum wells (QWs) bonded to a silicon waveguide. With this structure, the optical mode is predominantly confined in the passive silicon waveguide and is evanescently coupled to the AlGaInAs strained QWs. The optimal design of the optical waveguide for delivering sufficient optical gain to reach the lasing threshold, while confining most of the optical mode in the silicon waveguide, for efficiently coupling the output power into silicon passive devices, is described. The silicon waveguide is fabricated on a silicon-on-insulator (SOI) wafer using a CMOS-compatible process, and is subsequently bonded with the AlGaInAs QW structure using low temperature O-2 plasma-assisted wafer bonding. We demonstrate optically pumped silicon evanescent lasers operating continuous wave (CW) up to 60 degrees C. The lasers emit a wavelength of 1.5 mu m with a minimum threshold of 23 mW and a maximum single-sided fiber-coupled CW output power of 4.5 mW at the room temperature.