Optimizing photonic crystal micro ring resonators (PhC-MRRs) via bending supercell simulations

Area of Science:

• Photonics
• Nanotechnology
• Optical Engineering

Background:

• Photonic crystal micro-ring resonators (PhC-MRRs) offer compact, high-Q cavities for on-chip photonic integrated circuits.
• Designing PhC-MRRs faces challenges in mode matching and resonance analysis compared to traditional waveguide-based micro-ring resonators.

Purpose of the Study:

• To propose and analyze a novel PhC-MRR design overcoming traditional design hurdles.
• To achieve high-Q, pure guided cavity resonances with a predictable free spectral range.

Main Methods:

• Utilized an extended supercell approach incorporating straight and bending structures with optimized corners to satisfy periodicity requirements.
• Designed a hexagonal PhC-MRR with specific lattice constant (a=364 nm), filling factor (f0=0.33), radius (13a), and coupling gap (g=3a).

Main Results:

• The optimized PhC-MRR structure demonstrated a transmission spectrum with six equally spaced, high-Q pure guided cavity resonances.
• Achieved a free spectral range (FSR) of 18 nm across a broad bandwidth from 1500 nm to 1600 nm.

Conclusions:

• The proposed extended supercell method effectively addresses mode matching and resonance analysis challenges in PhC-MRRs.
• The developed hexagonal PhC-MRR design offers a promising platform for advanced on-chip photonic applications requiring stable, high-Q resonances.