Low-loss GaN-on-insulator platform for integrated photonics

Area of Science:

• Materials Science
• Photonics
• Semiconductor Physics

Background:

• III-Nitride semiconductors offer broad transparency for nonlinear optics.
• On-chip integrated photonics requires efficient nonlinear conversion platforms.
• Gallium Nitride (GaN) is a key III-Nitride material.

Purpose of the Study:

• To demonstrate a novel photonics platform using epitaxial Gallium Nitride-on-insulator (GaN-on-insulator) on silicon.
• To achieve high-quality factor resonators for telecommunication wavelengths.
• To demonstrate resonant second harmonic generation (SHG) for nonlinear optical applications.

Main Methods:

• Epitaxial growth of GaN on silicon.
• Wafer bonding to transfer GaN-on-insulator onto SiO2.
• Fabrication of photonic devices.
• Characterization of quality factors and nonlinear optical conversion efficiency.

Main Results:

• Achieved high quality factors (up to 230,000) at telecommunication wavelengths.
• Demonstrated resonant second harmonic generation (SHG).
• Obtained a continuous wave (CW) conversion efficiency of 0.24%/W for SHG.

Conclusions:

• The GaN-on-insulator on silicon platform is suitable for integrated photonics.
• High Q-factors and efficient nonlinear conversion are achievable.
• This platform enables on-chip second-order nonlinear optical processes.