Plasmonic near fields, wherein light is magnified and focused within nanoscale volumes, are utilized in a broad array of technologies including optoelectronics, catalysis, and sensing. Within nanoscale cavities such as those shown in Figure A-B to the right, increases in temperature are expected and indeed have been demonstrated. Heat generation can be beneficial or detrimental for a given system or technique, but in either case it is useful to have knowledge of the local temperature. In this work, subtle features in single-molecule surface-enhanced Raman spectra (Figure C) have been quantified as a means of achieving thermometry at the nanometer length scale.
