We report the extension of our formerly developed two-beam 3-color broadband coherent Raman methodology and the improvement of our tabletop system for fully polarization controlled low-frequency vibrational measurements. Each of the differently polarized partial signal in the coherent Raman scattering could be effectively eliminated at the theoretically predicted polarization analyzer orientations. The electronic contribution to the signal was suppressed without significantly reducing the vibrational contribution to the spectrum, which is a noteworthy advantage compared to Coherent anti-Stokes Raman Spectroscopy (CARS). The method was applied for well-characterized liquid CCl4 and CHCl3 samples for the first time. Coherent vibrational spectra were recorded simultaneously on the Stokes and anti-Stokes spectral-domain located near the zero frequency shift region. The methodology is easily extendable to measure vibrational or phonon spectra of anisotropic crystals.

We report the construction and characterization of a coherent Raman tabletop system utilizing a novel astigmatic optical focusing geometry, a broadband nanosecond optical parametric oscillator and volumetric Bragg filters assisting 3CBCRS measuring system for the first time. In order to illustrate the versatility of the measurements and reveal the molecular information obtainable, two well-characterized chemicals were selected. Polarization sensitive epi-detected 3CBCRS spectra of liquid CCl4 and calcite crystal were recorded and analyzed. An unexpected polarization dependence of the signals of the lowest frequency modes of CCl4 was observed. The 1122 third order susceptibility component was phase flipped. The non-resonant susceptibility normalized 1122 component was found to be larger than the 1111 component for the lowest vibrational modes. This anomalous comportment was attributable to the anisotropy Raman tensor invariant in the third order nonlinear susceptibility tensor.