Zero-coupling-gap degenerate band edge resonators in silicon photonics

Area of Science:

• Photonics
• Integrated Optics
• Materials Science

Background:

• Resonances near photonic band edges are crucial for optical devices.
• Quality factors of regular band edge resonators scale poorly with device size.
• Degenerate band edges offer potential for improved scaling and miniaturization.

Purpose of the Study:

• To design and analyze zero-coupling-gap degenerate band edge resonators for silicon integrated photonics.
• To investigate the impact of zero-coupling-gap designs on resonance scaling and quality factors.
• To optimize waveguide coupling for high transmission in compact resonators.

Main Methods:

• Computation of complex band diagrams for unit cells with periodic boundary conditions.
• Analysis of dispersion features to understand resonance scaling in finite resonators.
• Comparison of resonators with zero and non-zero coupling gaps.

Main Results:

• Zero-coupling-gap degenerate band edge resonators exhibit significantly improved resonance scaling (fifth power).
• Reduced number of periods required to achieve fifth power scaling compared to non-zero gap designs.
• Optimized waveguide feed achieved high transmission, demonstrating practical device feasibility.

Conclusions:

• Zero-coupling-gap degenerate band edge resonators enable significant device miniaturization in silicon photonics.
• These compact resonators with large optical field distribution are suitable for light emitters, switches, and sensors.
• The findings pave the way for next-generation compact and efficient photonic integrated circuits.