Room-temperature electrically pumped InGaN-based microdisk laser grown on Si.

Area of Science:

• Optoelectronics
• Materials Science
• Semiconductor Physics

Background:

• Silicon photonics requires efficient on-chip light sources for integrated circuits.
• Microdisk lasers utilize whispering gallery modes for efficient light emission into waveguides.
• Previous attempts at III-nitride microdisk lasers on silicon faced material quality and fabrication issues.

Purpose of the Study:

• To fabricate and demonstrate room-temperature, electrically pumped Indium Gallium Nitride (InGaN) microdisk lasers on a silicon substrate.
• To overcome the limitations of conventional undercut structures and dry etching processes for GaN microdisks.
• To achieve efficient light emission suitable for on-chip photonic integration.

Main Methods:

• Fabrication of InGaN-based microdisk structures directly grown on silicon.
• Characterization of electroluminescence properties under electrical injection.
• Analysis of spectral line-width narrowing and light output power versus injection current.

Main Results:

• Successful fabrication of room-temperature, electrically pumped InGaN microdisk lasers on silicon.
• Observed dramatic narrowing of electroluminescence spectral line-width, indicating lasing.
• Demonstrated a clear discontinuity in the light output power slope, confirming lasing operation.

Conclusions:

• This work presents the first observation of electrically pumped lasing in InGaN-based microdisk lasers grown on silicon at room temperature.
• The developed fabrication method overcomes previous challenges, enabling efficient on-chip light sources for silicon photonics.
• This achievement is a significant step towards the realization of integrated optoelectronic devices on silicon platforms.