Hybrid III-V and IV lasers and amplifiers

Silicon evanescent lasers and amplifiers have been demonstrated utilizing low temperature wafer bonding technology. This approach enables the creation of high performance, small footprint active devices on silicon for photonic integrated circuits. Introduction Photonic integration has progressed greatly in realizing various functions for optical interconnects as well as long haul communication systems. Silicon photonics is a promising platform to fabricate dense photonic integrated circuits on a large silicon wafer using highly accurate silicon processing technology. Raman lasers [1,2] and amplifiers [3], high speed modulators [4,5], and photo detectors [6,7] have been successfully demonstrated and have widened the applications of silicon as an optoelectronic material. However, a key hurdle for realizing practical silicon based photonic integrated circuit is achieving electrically pumped silicon lasers and amplifiers due to silicon’s indirect bandgap. Recently, electrically pumped silicon evanescent lasers [8,9] and amplifiers [10] have been demonstrated utilizing low temperature wafer bonding technology. This approach has led to the realization of active devices with compact size and high performance on silicon for photonic integrated circuits. Silicon evanescent device platform and general fabrication process The silicon evanescent device is a hybrid structure that consists of an offset multiple quantum well region bonded to a silicon waveguide which is fabricated on a silicon-on-insulator (SOI) wafer. With this architecture, the optical mode can obtain electrically pumped gain from the III-V region while being guided by the underlying silicon waveguide region. Silicon waveguide dimensions primarily determine the confinement factor of each region, i.e., quantum well or silicon waveguide region. In general, a wider or higher waveguide confines more of the optical mode in the silicon waveguide, while reducing the optical mode overlap with the quantum wells. Fig.1. Cross sectional structure of silicon evanescent