We discuss a technique for nonlinear Raman spectroscopy that utilizes two orthogonally polarized, frequency-degenerate pump waves whose relative phase is modulated. A phase-modulated signal wave results from the mixing of the pump waves and a probe wave through the third-order, nonlinear susceptibility X3. Heterodyne detection of the signal wave yields signals linear in X3, permits measurement of both the real and the imaginary parts of X3, and routinely provides shot-noise-limited sensitivities. Expressions for signal voltages are derived and typical spectra quantitatively analyzed.
© 1985 Optical Society of America
G. J. Rosasco and W. S. Hurst, "Phase-modulated stimulated Raman spectroscopy," J. Opt. Soc. Am. B 2, 1485-1496 (1985)