Work

Junction Plasmon Driven Population Inversion of Molecular Vibrations: A Picosecond Surface-Enhanced Raman Spectroscopy Study

Year: 2018

Type: article

Abstract: Molecular surface-enhanced Raman spectra recorded at single plasmonic nanojunctions using a 7 ps pulse train exhibit vibrational up-pumping and population inversion. The process is assigned to plasmon-driven, dark, impulsive electron-vibration (e-v) excitation. Both optical (Raman) pumping and hot-electron mediated excitation can be rejected by the characteristic spectra, which allow the simultaneous measurement of vibrational temperature of the molecules and electronic temperature of the metal. Vibrational populations are determined from anti-Stokes to Stokes intensity ratios, while the electron temperature is obtained from the anti-Stokes branch of the electronic Raman scattering continuum. Population inversion survives in high-frequency vibrations that effectively decouple from the metal.

Source: Nano Letters

DOI: 10.1021/acs.nanolett.8b02438

Authors: Kevin T. Crampton, Alexander Fast, Eric O. Potma, V. Ara Apkarian

Institution: University of California, Irvine

Language: English

Topic: Gold and Silver Nanoparticles Synthesis and Applications

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funder: Division of Chemistry

Award: G185394720