Enhanced chiroptical responses through coherent perfect absorption in a parity-time symmetric system
Year: 2022
Type: article
Abstract: Coherent amplification of chiroptical activity from a molecularly-thin optically-active substance has been a long-standing challenge due to the inherently weak nature of chiral responses. Here we report how a coherent perfect absorber (CPA) enabled by an achiral optical system obeying parity-time (PT) symmetry has an enhanced ability to effectively sense molecular chirality of monolayered substances. We demonstrate that such a CPA-based PT-symmetric system enables us in complete darkness to probe a subtle signal change induced by the introduction of a small disturbance, such as adsorbed chiral monolayer, to the unperturbed PT-symmetric system, and allows for absolute measurement and quantitative detection of the magnitude and sign of both real and imaginary parts of the chirality parameter in a background-free environment. Moreover, the CPA-based PT-symmetric system also exhibits three orders of magnitude enhancement in chiroptical responses of molecules, which is consistent with analytical calculations of differential absorption.
Source: Communications Physics
Authors: Hsin-Yu Wu, Frank Vollmer
Institution: University of Exeter
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,490
OpenAlex ID: W4226269564