Enhancement of molecular coherent anti-Stokes Raman scattering with silicon nano-antennas

TL;DR

This paper demonstrates enhanced molecular CARS signals using silicon nano-antennas, offering improved thermal stability over metallic nanoantennas, thus advancing the reliability of SE-CARS for biomolecular sensing.

Contribution

It introduces the first experimental use of silicon nano-antennas for SE-CARS, addressing stability issues associated with metallic nanoantennas under ultrafast excitation.

Findings

Enhanced molecular CARS signals observed at Si nano-antennas

Silicon nano-antennas exhibit superior thermal stability

Potential for more reliable biomolecular sensing applications

Abstract

Surface-enhanced coherent anti-Stokes Raman scattering (SE-CARS) takes advantage of surface plasmon resonances supported on metallic nanostructures to amplify the coherent Raman response of target molecules. While these metallic antennas have found significant success in SE-CARS studies, photo-induced morphological changes to the nanoantenna under ultrafast excitation introduce significant hurdles in terms of stability and reproducilibty. These hurdles need to be overcome in order to establish SE-CARS as a reliable tool for rapid biomolecular sensing. Here we address this challenge by performing molecular CARS measurements enhanced by nanoantennas made from high-index dielectric particles with more favorable thermal properties. We present the first experimental demonstration of enhanced molecular CARS signals observed at Si nano-antennas, which offer much improved thermal stability compared to their metallic counterparts.