Implementing photonic-crystal resonator frequency combs in a photonic foundry

Area of Science:

• Integrated Photonics
• Nonlinear Optics
• Materials Science

Background:

• Silicon nitride photonics offers a scalable platform for advanced optical devices.
• Photonic-crystal resonators (PhCRs) are key components for nonlinear optical phenomena.
• Achieving high-quality factors (Q) and precise dispersion is crucial for generating optical parametric oscillators (OPOs) and soliton microcombs.

Purpose of the Study:

• To explore the fabrication of PhCRs on a silicon nitride platform for OPOs and soliton microcombs.
• To leverage silicon nitride's scalability and fine feature size for low-loss, high-Q microresonators.
• To demonstrate the potential of this platform for a variety of nanophotonic sources.

Main Methods:

• Utilizing AIM Photonics silicon nitride platform for foundry fabrication on 300 mm silicon wafers.
• Integrating nanoscale photonic-crystal structures with a 700 nm silicon nitride device layer.
• Precisely engineering microresonator dispersion through photonic-crystal design.

Main Results:

• Demonstrated intrinsic microresonator quality factor up to 1.2 × 10⁷.
• Achieved broad tunability in OPO output frequency across the near-infrared.
• Observed the formation of soliton frequency combs due to precise dispersion engineering.

Conclusions:

• The silicon nitride platform enables accessible, photolithographically patterned nanophotonic sources.
• This technology facilitates complex integration of frequency comb sources.
• Applications include spectroscopy, metrology, and communications.