Surface Coherent Anti-Stokes Raman Spectroscopy

Abstract

Application of integrated optics to Coherent Anti-Stokes Raman Spectrosocpy (CARS) results in Surface CARS, a highly sensitive analytical tool for the study of adsorbed molecules on surfaces. In CARS two input laser beams at frequencies ω₁ and ω₂ interact non-1inearly producing an output signal at the frequency 2ω₁ -ω₂. This process is greatly enhanced when a vibrational resonance of a molecule occurs at the frequency ω₁ - ω₂. Thus, by tuning one of the two input frequencies, one can obtain a spectrum corresponding to an ordinary Raman spectrum of the interacting molecules.