Phosphorus-free 1.5  µm InAs quantum-dot microdisk lasers on metamorphic InGaAs/SOI platform

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• III-V semiconductor lasers on silicon are crucial for silicon photonics integration.
• Existing 1.5 µm lasers on silicon often use InP and contain phosphorus.
• Phosphorus-free 1.5 µm Indium Arsenide (InAs) quantum dot (QD) lasers on silicon and silicon-on-insulator (SOI) platforms remain underdeveloped.

Purpose of the Study:

• To demonstrate the first phosphorus-free InAs QD laser grown epitaxially on an SOI substrate.
• To achieve S-band emission at 1.5 µm for telecommunications.
• To explore the potential for integrated light sources on silicon.

Main Methods:

• Epitaxial growth of metamorphic InAs/InGaAs QDs on (111)-faceted SOI hollow structures.
• Fabrication of microdisk lasers with a 4 µm diameter.
• Characterization of lasing properties, including threshold power at cryogenic temperatures.
• Comparative analysis with microdisk lasers grown on Gallium Arsenide (GaAs) substrates.

Main Results:

• Successful demonstration of a phosphorus-free InAs QD microdisk laser on SOI emitting at the S-band.
• A seven-layer InAs QD microdisk laser (4 µm diameter) exhibited a lasing threshold power of 234 μW at 200 K.
• Comparative data from lasers grown on GaAs substrates were obtained.

Conclusions:

• This work presents a significant advancement towards on-chip 1.5 µm light sources for silicon photonics.
• The developed technology is a key step for realizing integrated light sources for long-haul telecommunications.
• The findings open new avenues for phosphorus-free QD lasers on silicon platforms.