Magnetic spin-orbit interaction directs Bloch surface waves
Abstract
We study the directional excitation of optical surface waves controlled by the magnetic field of light. We theoretically predict that a spinning magnetic dipole develops a tunable unidirectional coupling of light to TE-polarized Bloch surface waves (BSWs). Experimentally, we show that the helicity of light projected onto a subwavelength groove milled in the top layer of a 1D photonic crystal (PC) controls the power distribution between two TE-polarized BSWs excited on both sides of the groove. Such a phenomenon is shown to be mediated solely by the helicity of the magnetic field of light, thus revealing a magnetic spin-orbit interaction. Remarkably, this magnetic optical effect is clearly observed with a near-field coupler governed by an electric dipole moment: it is of the same order of magnitude as the electric optical effects involved in the coupling. The magnetic spin-orbit interaction opens new degrees of freedom in the manipulation of light and offers appealing novel opportunities in the development of integrated optical functionalities.
Keywords
Cite
@article{arxiv.1710.03584,
title = {Magnetic spin-orbit interaction directs Bloch surface waves},
author = {Mengjia Wang and Hongyi Zhang and Tatiana Kovalevitch and Roland Salut and Myun-Sik Kim and Miguel Angel Suarez and Maria-Pilar Bernal and Hans-Peter Herzig and Huihui Lu and Thierry Grosjean},
journal= {arXiv preprint arXiv:1710.03584},
year = {2017}
}