Tailoring the photon hopping by nearest and next-nearest-neighbour interaction in photonic arrays

TL;DR

This paper explores how nearest and next-nearest neighbor interactions influence photon hopping in photonic arrays, revealing that these interactions can be equally significant and can be engineered to control mode distribution and group velocity.

Contribution

It demonstrates that next-nearest-neighbor interactions are as important as nearest-neighbor ones in photonic arrays, enabling tailored mode control and waveguide properties.

Findings

Nearest and next-nearest-neighbor couplings are equally relevant.

Photon hopping is strongly affected by these interactions.

Configurations can be engineered to tailor mode distribution.

Abstract

Arrays of photonic cavities are relevant structures for developing large-scale photonic integrated circuits and for investigating basic quantum electrodynamics phenomena, due to the photon hopping between interacting nanoresonators. Here, we investigate, by means of scanning near-field spectroscopy, numerical calculations and an analytical model, the role of different neighboring interactions that give rise to delocalized supermodes in different photonic crystal array configurations. The systems under investigation consist of three nominally identical two-dimensional photonic crystal nanocavities on membrane aligned along the two symmetry axes of the triangular photonic crystal lattice. We find that the nearest and next-nearest-neighbour coupling terms can be of the same relevance. In this case, a non-intuitive picture describes the resonant modes, and the photon hopping between adjacent nano-resonators is strongly affected. Our findings prove that exotic configurations and even post-fabrication engineering of coupled nanoresonators could directly tailor the mode spatial distribution and the group velocity in coupled resonator optical waveguides.