Observation of high-order imaginary Poynting momentum optomechanics in structured light

TL;DR

This paper demonstrates the first experimental observation of high-order imaginary Poynting momentum forces in structured light, revealing new optomechanical effects on particles through nonlinear optical force contributions.

Contribution

It introduces the first observation of high-order IPM forces on Mie particles, expanding understanding of optical forces and enabling advanced micromanipulation techniques.

Findings

High-order IPM forces observed in structured light beams.

Suppression of low-order dipolar contributions in experiments.

Evidence supporting the ponderomotive nature of IPM.

Abstract

The imaginary Poynting momentum (IPM) of light has been captivated an unusual origin of optomechanical effects on dipolar magnetoelectric particles, but yet observed in experiments. Here, we report, for the very first time, a whole family of high-order IPM forces for not only magnetoelectric but also generic Mie particles, assisted with their excited higher multipoles within. Such optomechanical phenomena derive from a nonlinear contribution of the IPM to the optical force, and can be remarkable even when the incident IPM is small. We observe the high-order optomechanics in a structured light beam with vortex-like IPM streamlines, which allows the low-order dipolar contribution to be suppressed. Our results provide the first unambiguous evidence of the ponderomotive nature of the IPM, expand the classification of optical forces and open new possibilities for optical forces and micromanipulations.