Ultra-high-Q thin-silicon nitride strip-loaded ring resonators

Area of Science:

• Photonics and Optical Engineering
• Materials Science and Engineering
• Integrated Optics

Background:

• Ring resonators are crucial for optical signal processing.
• Achieving ultra-high quality factors (UHQs) is essential for advanced photonic applications.
• Traditional silicon nitride (Si3N4) devices face limitations in performance and fabrication.

Purpose of the Study:

• To design, fabricate, and characterize novel thin Si3N4 ring resonators.
• To demonstrate the effectiveness of a strip-loaded configuration for enhanced optical performance.
• To explore the potential of these resonators for nonlinear optics and quantum computing.

Main Methods:

• Monolithic integration of Si3N4 on a silicon chip.
• Utilizing a strip-loaded resonator design to minimize lateral boundary scattering.
• Characterization of device performance at near-infrared (NIR) and C-band wavelengths.

Main Results:

• Achieved UHQs of 3.7×10^6 in the NIR and Q factors up to 9×10^5 in the C-band.
• Demonstrated performance with a significantly thinner Si3N4 guiding core (80 nm and 115 nm).
• Observed reduced scattering losses due to the absence of etched lateral boundaries.

Conclusions:

• The strip-loaded Si3N4 ring resonators offer a promising platform for high-performance integrated photonics.
• The achieved UHQs pave the way for applications in nonlinear frequency conversion and quantum computing.
• Further improvements are expected to enhance device applicability within the material's transparency window.