Precise characterization of the Raman nonlinearity in benzene using nonlinear interferometry

Abstract

Using a newly developed technique which we term two‐beam nonlinear interferometry, we report accurate self‐consistent determinations of both the real and imaginary parts of the third‐order nonlinear optical susceptibility χ¹¹¹¹₃(−ω,ω,ω_o,−ω_o) in benzene including resonant Raman contributions from the 992‐cm⁻¹ mode. These measurements provide accurate values for the peak Raman cross section, nonlinear refractive index, and electronic hyperpolarizability, thus enabling the direct comparison of Raman, nonlinear refractivity, and frequency‐mixing studies.