Gold-induced photothermal background in on-chip surface enhanced stimulated Raman spectroscopy

Surface enhanced Raman spectroscopy (SERS) and stimulated Raman spectroscopy (SRS) are well established techniques capable of boosting the strength of Raman scattering. The combination of both techniques (surface enhanced stimulated Raman spectroscopy, or SE-SRS) has been reported using plasmonic nanoparticles. In parallel, waveguide enhanced Raman spectroscopy has been developed using nanophotonic and nanoplasmonic waveguides. Here, we explore SE-SRS in nanoplasmonic waveguides. We demonstrate that a combined photothermal and thermo-optic effect in the gold material induces a strong background signal that limits the detection limit for the analyte. The experimental results are in line with theoretical estimates. We propose several methods to reduce or counteract this background. (C) 2021 Optical Society of America

Automated summary

This article explores surface-enhanced stimulated Raman spectroscopy (SE-SRS) in nanoplasmonic waveguides, revealing that a combined photothermal and thermo-optic effect in gold material leads to a strong background signal that limits the detection limit for analytes. Experimental results align with theoretical estimates, and several methods to reduce or counteract this background are proposed.