Membrane buried-heterostructure DFB laser with an optically coupled III-V/Si waveguide

Area of Science:

• Optoelectronics
• Materials Science
• Nanotechnology

Background:

• Silicon photonics offers a scalable platform for integrated optical circuits.
• III-V semiconductors are essential for laser light generation.
• Integrating III-V materials with silicon photonics presents fabrication challenges.

Purpose of the Study:

• To develop a membrane buried-heterostructure (BH) distributed feedback (DFB) laser.
• To enable efficient optical coupling between III-V gain material and silicon waveguides.
• To leverage conventional silicon photonics platforms for laser integration.

Main Methods:

• Fabrication of a BH-DFB laser using direct wafer bonding and metalorganic vapor phase epitaxy regrowth.
• Integration of a 230-nm-thick III-V membrane with a 220-nm-thick silicon waveguide.
• Design of an inverse-taper InP waveguide for light transfer to a silicon waveguide and fiber coupling.

Main Results:

• Demonstrated an optically coupled III-V/Si waveguide and SiN surface grating.
• Achieved a fiber coupling power of 7.9 mW with a 500-µm-long cavity laser.
• Obtained single-mode lasing with a side-mode suppression ratio of 50 dB and operation up to 120°C.

Conclusions:

• The developed membrane BH-DFB laser is compatible with standard silicon photonics platforms.
• The design allows control over optical confinement by adjusting silicon waveguide width.
• This integration facilitates high-performance silicon-based optoelectronic devices.