Strong Coupling between On Chip Notched Ring Resonator and Nanoparticle

TL;DR

This paper introduces a novel on-chip notched ring resonator structure that enables strong optical coupling with nanoparticles, allowing for enhanced spectral shifts and the ability to distinguish nanoparticle types, advancing nanoparticle sensing technology.

Contribution

The paper presents a new on-chip notched ring resonator design that significantly improves nanoparticle detection sensitivity and enables nanoparticle type differentiation.

Findings

Achieved large spectral shifts and splittings at nanometer scale.

Lowered the quality factor requirement for detection.

Demonstrated differentiation between dielectric and metallic nanoparticles.

Abstract

We have demonstrated a new photonic structure to achieve strong optical coupling between nanoparticle and photonic molecule by utilizing a notched micro ring resonators. By creating a notch in the ring resonator and putting a nanoparticle inside the notch, large spectral shifts and splittings at nm scale can be achieved, compared to only pm scale observed by fiber tip evanescently coupled to the surface of microsphere, thereby significantly lowered the quality factor requirement for single nanoparticle detection. The ability for sorting the type of nanoparticles due to very different mode shift and splitting behavior of dielectric and metallic nanoparticles is also emphasized.