Heat Generation in Spatially Confined Solids Through Electronic Light Scattering

TL;DR

This paper investigates how electronic light scattering causes optical heating in spatially dispersive solids, demonstrated by melting silicon and gold with continuous laser pumping, revealing a key process for thermo-optical applications.

Contribution

It introduces the phenomenon of electronic light scattering-induced heating in spatially confined solids and experimentally demonstrates its significance in melting semiconductors and metals.

Findings

ELS causes significant optical heating in confined solids

Experimental melting of Si and Au confirms ELS's role in thermo-optical effects

ELS is a dominant process in media with strong spatial dispersion

Abstract

In this Letter, we study the optical heating of spatially dispersive solids due to electronic light scattering (ELS), a phenomenon driven by indirect optical transitions. In this process, a spatial heterogeneity generates an optical near-field photon with expanded momentum, leading to electron-photon momentum matching, followed by thermalization of the electron system promoting optical heating. We experimentally demonstrate this effect by melting spatially confined semiconductor (Si) and metal (Au) under continuous-wave laser pump within the transparency window. ELS is a dominant physical process in media with strong spatial dispersion, underlying a variety of thermo-optical applications.