A Defect-Free Vertical-Cavity GaAs-Based Nanowire Laser on Silicon Emitting at the Telecom O-Band

Area of Science:

• Optoelectronics
• Materials Science
• Nanotechnology

Background:

• Vertical-cavity nanowire (NW) lasers are crucial for silicon photonics.
• Integrating GaAs-based NW lasers on silicon has been a significant challenge.

Purpose of the Study:

• To demonstrate the direct site-selective integration of a GaAs-based NW laser on Si.
• To achieve lasing emission in the telecom O-band from the integrated NW laser.

Main Methods:

• Fabrication of an advanced NW heterostructure with an InGaAs/InAlGaAs multiple quantum well (MQW) active gain region.
• Coaxial integration of the MQW on a vertical GaAsSb NW core with high Sb content.
• Characterization using scanning transmission electron microscopy and nanobeam electron diffraction.

Main Results:

• Successful direct site-selective integration of a vertical-cavity GaAs-based NW laser on Si.
• Lasing emission observed at the telecom O-band (~1.3 μm) in the as-grown geometry.
• Uniform MQW composition, minimal strain (<1.3 ± 0.2%), and absence of extended defects confirmed.
• Single-mode lasing achieved across a range of temperatures with low thresholds (160 μJ/cm²).

Conclusions:

• The developed heterostructure enables efficient lasing in GaAs-based NWs on Si.
• This work overcomes previous integration challenges for GaAs NW lasers in Si photonics.
• The demonstrated NW laser is a promising light source for integrated silicon photonics applications.