Topology Optimization of Surface-enhanced Raman Scattering Substrates

TL;DR

This paper demonstrates how topology optimization can be used to design nanostructured SERS substrates with enhanced performance, achieving significant improvements in Raman signal amplification while considering fabrication constraints.

Contribution

It introduces the application of topology optimization to design SERS substrates, enabling tailored nanostructures with improved enhancement factors and fabrication feasibility.

Findings

Achieved a SERS enhancement factor of 5×10^4 for rhodamine 6G.

Topology optimization can produce nanostructures with orders of magnitude higher enhancement.

Validated topology optimization as an effective design tool for nanostructured SERS substrates.

Abstract

Surface-enhanced Raman spectroscopy is a powerful and versatile sensing method with a detection limit down to the single molecule level. In this article, we demonstrate how topology optimization (TopOpt) can be used for designing surface enhanced Raman scattering (SERS) substrates adhering to realistic fabrication constraints. As an example, we experimentally demonstrated a SERS enhancement factor of 5*10e4 for the 604 cm-1 Raman line of rhodamine 6G using metal nanostructures with a critical dimension of 20 nm. We then show that, by relaxing the fabrication constraints, TopOpt may be used to design SERS substrates with orders of magnitude larger enhancement factor. The results validate topology optimization as an effective method for engineering nanostructures with optimal performance and fabrication tolerance.