Ridge Resonance: A new Resonance Phenomenon for Silicon Photonics Harnessing Bound States in the Continuum

TL;DR

This paper introduces a novel resonance phenomenon in silicon photonics based on bound states in the continuum, demonstrated experimentally with sharp resonance features suitable for integrated photonic applications.

Contribution

It presents the first experimental demonstration of bound states in the continuum resonance using guided wave silicon photonic components.

Findings

Sharp resonance near 1550 nm with a few nanometers linewidth

Extinction ratio of 25 dB achieved

Thermal stability of 19.5 pm/°C

Abstract

We present a new resonant behavior based on bound states in the continuum in a guided wave silicon platform. The continuum has the form of a collimated beam of light which is confined vertically in a TE mode of a silicon slab. The bound state is a discrete TM mode of a ridge on the silicon slab. The coupling between the slab and ridge modes results in a single sharp resonance at the wavelength where they phase match. We experimentally demonstrate this phenomenon on a silicon photonic chip using foundry compatible parameters and interface it on-chip to standard single mode silicon nanowire waveguides. The fabricated chip exhibits a single sharp resonance near 1550 nm with a line width of a few nanometer, an extinction ratio of 25 dB and a thermal stability of 19.5 pm/C. We believe that this is the first demonstration of bound states in the continuum resonance realized using guided wave components.