V. Astinov et al., Diffractive optics based two-color six-wave mixing: phase contrast heterodyne detection of the fifth order Raman response of liquids, CHEM P LETT, 327(5-6), 2000, pp. 334-342
Fifth order Raman scattering is extremely sensitive to anharmonicities and
nonlinear polarizabilities and thus provides a unique probe of the many-bod
y potential of Liquids. The weak signals from this high order, chi((5)), pr
ocess are complicated by cascaded lower-order chi((3)) processes. A new app
roach has reduced the beam delivery to a single diffractive optic that gene
rates the beam pattern for phase-matched six-wave mixing, and passively pha
se Locks all six fields. Heterodyne detection introduces signal amplificati
on and phase contrast against lower-order nonlinearities. The findings prov
ide new Insight into the nature of the direct chi((5)) nonlinear response f
unction and two-time correlation of liquids. (C) 2000 Elsevier Science B.V.
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