Monolithic integration of embedded III-V lasers on SOI

Area of Science:

• Photonics
• Materials Science
• Semiconductor Engineering

Background:

• Silicon photonics offers excellent device properties and CMOS compatibility.
• Monolithic integration of III-V lasers with silicon photonics remains a significant challenge for ultra-dense integration.

Purpose of the Study:

• To demonstrate monolithic integration of III-V quantum dot lasers directly grown on silicon-on-insulator (SOI) substrates.
• To overcome long-standing obstacles in on-chip light source development for photonic integration.

Main Methods:

• Direct epitaxial growth of InAs/GaAs quantum dot (QD) lasers on trenched SOI substrates using hybrid molecular beam epitaxy (MBE).
• Utilizing patterned grating structures within SOI trenches for monolithic out-coupling.
• Addressing epitaxy and fabrication challenges in the integrated architecture.

Main Results:

• Achieved high-performance embedded InAs QD lasers monolithically integrated with butt-coupled silicon waveguides.
• Demonstrated continuous-wave (CW) lasing up to 85°C.
• Measured maximum output power of 6.8 mW from silicon waveguides with ~ -6.7 dB coupling efficiency.

Conclusions:

• Presented a scalable, low-cost epitaxial method for on-chip III-V lasers on SOI.
• Enabled direct coupling of light sources to silicon photonic components.
• Paved the way for future high-density photonic integration.