Optical tornadoes in photonic crystals

TL;DR

This paper theoretically investigates optical tornadoes in 2D photonic crystals, linking their formation to Berry curvature and demonstrating control via dielectric tuning, with potential applications in optical manipulation.

Contribution

It introduces the concept of optical tornadoes in photonic crystals and shows how to control them through Berry curvature manipulation in a novel way.

Findings

Optical tornadoes are linked to large Berry curvature in photonic crystals.

Tuning dielectric rods controls the Berry curvature and tornado formation.

Analysis of radiation force suggests potential applications in optical manipulation.

Abstract

Based on an optical analogy of spintronics, the generation of optical tornadoes is theoretically investigated in two-dimensional photonic crystals without space-inversion symmetry. We address its close relation to the Berry curvature in crystal momentum space, which represents the non-trivial geometric property of a Bloch state. It is shown that the Berry curvature is easily controlled by tuning two types of dielectric rods in a honeycomb photonic crystal. Then, Bloch states with large Berry curvatures appear as optical tornadoes in real space. The radiation force of such a configuration is analyzed, and its possible application is also discussed.