Pancharatnam-Berry phase induced spin-selective transmission in herringbone dielectric metamaterials

TL;DR

This paper introduces a dielectric metamaterial that achieves broadband, high-efficiency spin-selective transmission of terahertz waves using Pancharatnam-Berry phase control, offering a robust alternative to complex, lossy structures.

Contribution

It presents a novel silicon herringbone dielectric metamaterial design that utilizes PB phases for efficient spin-selective transmission in the terahertz range.

Findings

Achieves over 60% spin-selective efficiency.

Operates broadband in the terahertz regime.

Robust against fabrication errors.

Abstract

Manipulating the polarisation of light is crucial for sensing and imaging applications. One such aspect in particular is selective transmission of one circular polarisation (spin) when light is transmitted through a medium or a device. However, most present methods of achieving this have relatively low efficiency and selectivity, whilst high selectivity examples rely on lossy and complex three-dimensional helical or multilayer structures. Here, we propose a dielectric metamaterial approach for achieving spin-selective transmission of electromagnetic waves, utilizing spin-controlled constructive or destructive interference between two Pancharatnam-Berry (PB) phases in conjunction with propagative dynamic phase. The dielectric metamaterial, consisting of monolithic silicon herringbone structures, exhibits a broadband operation in the terahertz regime whilst obtaining a spin-selective efficiency upwards of 60%. Such a device is robust and is not easily degraded by errors in fabrication.