Surface-Enhanced Raman Scattering (SERS) and Surface-Enhanced Fluorescence (SEF) in the context of modified spontaneous emission

TL;DR

This paper presents a unified theoretical framework for understanding and calculating the electromagnetic enhancement mechanisms behind Surface-Enhanced Raman Scattering (SERS) and Surface-Enhanced Fluorescence (SEF), linking them through modified spontaneous emission.

Contribution

It introduces a rigorous, reciprocal theorem-based approach that unifies the electromagnetic enhancement descriptions of SERS and SEF, including a generalized enhancement factor.

Findings

Validates the $|E|^4$ enhancement factor for SERS

Provides a unified electromagnetic framework for SERS and SEF

Offers new insights into the electromagnetic enhancement mechanisms

Abstract

Surface Enhanced Raman Scattering (SERS) and Surface-Enhanced Fluorescence (SEF) are studied within the framework of modified Spontaneous Emission (SE), and similarities and differences are highlighted. This description sheds new light into several aspects of the SERS electromagnetic enhancement. In addition, combined with the optical reciprocity theorem it also provides a rigorous justification of a generalized version of the widely used SERS enhancement factor proportional to the fourth power of the field ($|E|^4$). We show, in addition, that this approach also applies to the calculation of Surface-Enhanced Fluorescence cross-sections thus presenting both phenomena SERS and SEF within a unified framework.