Widely separated optical Kerr parametric oscillation in AlN microrings

Area of Science:

• Photonics
• Materials Science
• Nonlinear Optics

Background:

• Optical parametric oscillation (OPO) is crucial for generating tunable light.
• Aluminum nitride (AlN) offers unique nonlinear optical properties for integrated photonics.
• Achieving wide frequency separation in OPO is challenging but desirable for various applications.

Purpose of the Study:

• To demonstrate chi(3)-based OPO in crystalline aluminum nitride microrings.
• To achieve widely separated signal-idler frequencies for chip-scale light sources.
• To explore wavelength tunability and frequency comb generation from the OPO.

Main Methods:

• Utilizing crystalline aluminum nitride microrings for nonlinear optical processes.
• Pumping the microrings at 2 µm to initiate optical parametric oscillation.
• Tailoring microring width for dispersion engineering and achieving frequency separation.

Main Results:

• Achieved OPO with signal-idler frequencies separated by 64.2 THz, spanning telecom and mid-infrared bands.
• Demonstrated OPO sideband shift of >9 THz by altering microring width.
• Showcased agile OPO frequency tuning (1 THz and 0.1 THz) via pump wavelength and temperature control.
• Observed OPO sidebands evolving into localized frequency comb lines at high pump powers.

Conclusions:

• The developed AlN microring OPO enables large frequency shifts and flexible wavelength tunability.
• This technology paves the way for enhanced, chip-scale light sources.
• The findings have implications for integrated photonics and frequency generation applications.