An exploration of lateral optical forces from a triangular periodic motif

TL;DR

This study computationally explores how asymmetric triangular nanostructures produce lateral optical forces, revealing resonant behaviors and interference effects that influence force responses, guiding the design of optically-driven systems.

Contribution

It uncovers the relationship between geometry, resonant modes, and optical forces in triangular motifs, highlighting stable zones and switching behaviors for the first time.

Findings

Stable force zones identified through parameter analysis.

Asymmetric lineshapes indicate Fano-resonance effects.

Eigenmode analysis links Q-factors to force transition sharpness.

Abstract

This computational study investigates lateral optical forces in asymmetric dielectric nanostructures, focusing on their connection to resonant light-matter interactions. We examine isosceles triangular motifs that exhibit two distinct types of optical force response under plane wave illumination. Through parameter-space analysis, we identify stable zones where optical forces remain consistent and switching bands where forces change abruptly as parameters are altered. The observed force spectra show characteristic asymmetric lineshapes, suggesting Fano-resonance behavior. Eigenfrequency analysis confirms these effects arise from interference between discrete eigenmodes and continuum propagation states, with the eigenmode Q-factors correlating with transition sharpness. These findings provide insights into how structural geometry influences optical forces through resonant effects, offering guidance for designing optically-driven systems where controlled optical force responses are desired.