# A surface plasmon platform for angle-resolved chiral sensing

## TL;DR

This paper introduces an angle-resolved surface plasmon resonance technique capable of detecting the absolute chirality of samples with high sensitivity, applicable using existing instrumentation and providing detailed insights into chiral properties.

## Contribution

It presents a novel CHISPR method that measures absolute chirality and distinguishes real and imaginary refractive index components without complex fabrication.

## Key findings

- Predicts signals in the millidegree range for <100nm chiral samples
- Analytical and numerical validation of the CHISPR scheme
- Clarifies the physics behind far-field chiral measurements

## Abstract

Chiral sensitive techniques have been used to probe the fundamental symmetries of the universe, study biomolecular structures, and even develop safe drugs. As chiral signals are inherently weak and often suppressed by large backgrounds, different techniques have been proposed to overcome the limitations of traditionally used chiral polarimetry. Here, we propose an angle-resolved chiral surface plasmon resonance (CHISPR) scheme that can detect the absolute chirality (handedness and magnitude) of a chiral sample and is sensitive to both the real and imaginary part of a chiral sample's refractive index. We present analytical results and numerical simulations of CHISPR measurements, predicting signals in the mdeg range for chiral samples of <100nm thickness at visible wavelengths. Moreover, we present a theoretical analysis that clarifies how our far-field measurements elucidate the underlying physics. This CHISPR protocol does not require elaborate fabrication and has the advantage of being directly implementable on existing surface plasmon resonance instrumentation.