Strong Anomalous Optical Dispersion of Graphene: Complex Refractive Index Measured by Picometrology

TL;DR

This study measures the complex refractive index of graphene across visible wavelengths, revealing an unusually strong optical dispersion that surpasses bulk graphite, using a precise picometrology technique.

Contribution

The paper introduces a novel application of spinning-disc picometrology to accurately measure graphene's complex refractive index and its strong dispersion properties.

Findings

Refractive index varies significantly from 2.4-1.0i to 3.0-1.4i between 532 nm and 633 nm.

Graphene's dispersion is five times stronger than bulk graphite.

Measured optical properties provide insights into graphene's unique optical behavior.

Abstract

We apply spinning-disc picometrology to measure the complex refractive index of graphene on thermal oxide on silicon. The refractive index varies from n = 2.4-1.0i at 532 nm to n = 3.0-1.4i at 633 nm at room temperature. The dispersion is five times stronger than bulk graphite (2.67-1.34i to 2.73-1.42i from 532 nm to 633 nm).