High power, narrow linewidth, low noise, integrated CMOS tunable laser for long haul coherent applications

An integrated-CMOS-tunable-laser with 15-dBm output power is presented. Fabrication is realized in commercial CMOS foundry. Laser shows high power, low RIN, and ultra-narrow linewidth. Performance over fiber is comparable with best-in-class, market-leading ITLA, proving suitability for long haul coherent applications. CMOS Laser Fabrication Process The fabrication of the CMOS tunable laser is realized in a commercial CMOS foundry. There are three major steps for processing the laser device: front-end-of-line (FEOL), middle-of-line (MOL), and back-end-of-line (BEOL). The FEOL consists of the definition of all passive and active silicon regions as well as the receptor sites for bonding of the unprocessed III- V gain material. Conventional silicon on insulator (SOI) wafers are used with a 2 µm buried oxide (BOX) layer and 1.5 µm crystalline silicon (c-Si) device. Gratings and waveguides are defined first, followed by resistive thermal devices, and heaters. The FEOL is finished with the etching of receptor sites for the III-V gain