Gain-Assisted Optomechanical Position Locking of Metal/Dielectric Nanoshells in Optical Potentials

TL;DR

This paper explores how gain-assisted optical forces can be used to trap and manipulate metal/dielectric nanoshells in optical potentials, demonstrating nonlinear trapping and particle channeling through theoretical and simulation methods.

Contribution

It introduces a novel approach combining gain-assisted forces with optical trapping of nanoshells, enabling enhanced control and manipulation of nanophotonic systems.

Findings

Nonlinear optical trapping achieved at high gains.

Particle channeling observed with blue-detuned wavelengths.

Theoretical and Brownian dynamics simulations confirm trapping mechanisms.

Abstract

We investigate gain-assisted optical forces on dye-enriched silver nanoshell in the quasi-static limit by means of a theoretical/numerical approach. We demonstrate the onset of nonlinear optical trapping of these resonant nanostructures in a counterpropagating Gaussian beam configuration. We study the optical forces and trapping behaviour as a function of wavelength, particle gain level, and laser power. We support the theoretical analysis with Brownian dynamics simulations that show how particle position locking is achieved at high gains in extended optical trapping potentials. Finally, for wavelengths blue-detuned with respect to the plasmon-enhanced resonance,we observe particle channeling by the standing wave antinodes due to gradient force reversal. This work opens perspectives for gain-assisted optomechanics where nonlinear optical forces are finely tuned to efficiently trap, manipulate, channel, and deliver externally controlled nanophotonic system.