III–V gain region/Si waveguide hybrid lasers with InP-based two-storied ridge structure by direct bonding technology

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.