Whispering-gallery modes promote enhanced optical backflow in a perforated dielectric microsphere
Abstract
Optical energy flow inside a dielectric microsphere is usually codirected with the optical wavevector. At the same time, if the optical field in a microsphere is in resonance with one of the high-quality spatial eigenmodes (whispering-gallery modes - WGMs), a region of reverse energy flow emerges in the shadow hemisphere. This area is of considerable practical interest due to increased optical trapping potential. In this Letter, we consider a perforated microsphere with an air-filled single pinhole fabricated along the particle diameter and numerically analyze the peculiarities of WGM excitation in a nanostructured microsphere. A pinhole isolates the energy backflow region of a resonant mode and changes a perforated microsphere into an efficient optical tweezer. For the first time to our knowledge, we reveal the multiple enhancement of backflow intensity in the pinhole at a WGM resonance and discuss the way for its manipulation.
Keywords
Cite
@article{arxiv.2112.14907,
title = {Whispering-gallery modes promote enhanced optical backflow in a perforated dielectric microsphere},
author = {Yury E. Geints and Igor V. Minin and Oleg V. Minin},
journal= {arXiv preprint arXiv:2112.14907},
year = {2022}
}
Comments
4 pages, 3 figures