III–V gain region/Si waveguide hybrid lasers with InP-based two-storied ridge structure by direct bonding technology
Takehiko Kikuchi, Takuo Hiratani, Naoki Fujiwara, Naoko Inoue, Toshiyuki Nitta, Moataz Eissa, Takuya Mitarai, Yuning Wang, Yoshitaka Oiso, Nobuhiko Nishiyama, Hideki Yagi
Abstract
Abstract We have fabricated III–V gain region/Si waveguide hybrid lasers with an InP-based two-storied ridge structure using direct bonding technology. Continuous-wave operation at a temperature of 20 °C with a threshold current as low as 30 mA was obtained for a hybrid laser consisting of a Fabry–Perot cavity with facets formed on the Si waveguide, and it was achieved thanks to a high optical coupling efficiency of over 80% at the interface between the III–V gain region and the Si waveguide using a two-storied ridge structure and a taper waveguide. The wavelength tunable laser which is comprised of a Si cavity with a loop mirror and double ring filters and III–V gain regions with laser and semiconductor optical amplifier (SOA) sections was demonstrated by utilizing this hybrid structure. It exhibited a wide wavelength tuning range of 48.6 nm and an optical amplification of 10 dB by SOA.