Transmission properties of microwaves at an optical Weyl point in a three-dimensional chiral photonic crystal

TL;DR

This study investigates microwave transmission through a 3D chiral photonic crystal with Weyl points, revealing inverse quadratic dependence on length, wave collimation, and cloaking effects near Weyl points.

Contribution

It provides the first experimental analysis of microwave transmission properties at Weyl points in a 3D chiral photonic crystal.

Findings

Transmission intensity inversely proportional to square of propagation length.

Well-collimated transmitted waves even for point-source incidence.

Reconstruction of wavefront indicating cloaking effect.

Abstract

Microwave transmission measurements were performed for a three-dimensional (3D) layer-by-layer chiral photonic crystal (PhC), whose photonic band structure contains 3D singular points, Weyl points. For the frequency and wavevector in the vicinity of a Weyl point, the transmitted intensity was found to be inversely proportional to the square of the propagation length. In addition, the transmitted wave was well-collimated in the plane parallel to the PhC layers, even for point-source incidence. When a plane wave was incident on the PhC containing metal scatters, the planar wavefront was reconstructed after the transmission, indicating a cloaking effect.