Tunable coupling-induced resonance splitting in self-coupled Silicon ring cavity with robust spectral characteristics

TL;DR

This paper introduces a self-coupled silicon microring resonator that achieves tunable resonance splitting with robust spectral features, useful for sensing and optical processing, demonstrating significant FSR splitting with stable quality factors.

Contribution

The study presents a novel self-coupled microring design that enables tunable resonance splitting and demonstrates its robustness and potential applications in integrated photonics.

Findings

Achieved 72% FSR splitting with <5% variation in Q factor.

Demonstrated stable spectral characteristics suitable for sensing.

Validated the effectiveness of self-coupling in silicon microring resonators.

Abstract

We propose and demonstrate a self-coupled microring resonator for resonance splitting by mutual mode coupling of cavity mode and counter-propagating mode in Silicon-on-Insulator platform The resonator is constructed with a self-coupling region that can excite counter-propagating mode. We experimentally study the effect of self-coupling on the resonance splitting, resonance extinction, and quality-factor evolution and stability. Based on the coupling, we achieve 72% of FSR splitting for a cavity with FSR 2.1 nm with < 5% variation in the cavity quality factor. The self-coupled resonance splitting shows highly robust spectral characteristic that can be exploited for sensing and optical signal processing.