Near-Field Enhanced UV Resonance Raman Spectroscopy Using Aluminum Bow-tie Nano-antenna

Abstract

An aluminum bow-tie nano-antenna is combined with the resonance Raman eect in the deep ultraviolet to dramatically increase the sensitivity of Raman spectra to a small volume of material, such as benzene used here. We further demonstrate gradient-eld Raman peaks for several strong IR modes. We achieve a gain of 105 in signal intensity from the near eld enhancement due to the surface plasmon resonance in the aluminum nanostructure. The on-line resonance enhancement contributes another factor of several thousands, limited by the laser line width. Thus, an overall gain of hundreds of million is achieved.