Membrane III-V/Si DFB Laser using Uniform Grating and Width-Modulated Si Waveguide

Takuma Aihara, Tatsurou Hiraki, Takuro Fujii, Koji Takeda, Takaaki Kakitsuka, Tai Tsuchizawa, Shinji Matsuo
2020 Journal of Lightwave Technology  
Membrane buried-heterostructure III-V/Si distributed feedback (DFB) lasers with a stopband-modulated cavity on a Si substrate have been developed. The membrane III-V layers with 230-nm thickness enable us to construct an optical supermode with a 220-nm-thick Si waveguide that is used in standard Si photonics platform. We employ a uniform grating and Si waveguide, in which Si waveguide width is modulated to control the center wavelength of the stopband. The cavity can be designed by controlling
more » ... he modulation width and modulation length of Si waveguide. Therefore, it is easy to engineer and fabricate the laser cavity compared with the cavity using λ/4-phase shift grating. Output light from the cavity is coupled to Si waveguide through InP inverse taper waveguide, and then coupled to SiO x waveguide through Si inverse taper waveguide, which provides the 2-dB fiber coupling loss. We have demonstrated single-mode lasing by using Si waveguide, where its width is increased 80 nm at the center of the cavity. The threshold current and maximum fiber output power are 3 mA and 4 mW, respectively. By extending the active region length to 1 mm, 17-mW fiber coupled output power is obtained. High-temperature operation up to 130°C is also obtained with a 1-mW fiber output power.
doi:10.1109/jlt.2020.2978808 fatcat:7e5m2gxasngjdndes7ydidvqtu