# 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.

## Key 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.

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Source: https://tomesphere.com/paper/1706.03810