Confocal microphotoluminescence mapping of coupled and detuned states in photonic molecules

TL;DR

This study uses confocal microphotoluminescence to spatially map and analyze the coupled and detuned states of photonic molecules, revealing how disorder influences mode coupling and light localization.

Contribution

It introduces a method to visualize and quantify mode coupling and detuning effects in photonic molecules under disorder conditions.

Findings

Mapped symmetric and antisymmetric modes in coupled cavities

Tracked transition from strong to weak coupling regimes

Quantified disorder-induced light localization

Abstract

We study the coupling of cavities defined by the local modulation of the waveguide width using confocal photoluminescence microscopy. We are able to spatially map the profile of the antisymmetric (antibonding) and symmetric (bonding) modes of a pair of strongly coupled cavities(photonic molecule) and follow the coupled cavity system from the strong coupling to the weak coupling regime in the presence of structural disorder. The effect of disorder on this photonic molecule is also investigated numerically with a finite-difference time-domain method and a semi-analytical approach, which enables us to quantify the light localization observed in either cavity as a function of detuning.