A modulation technique for measuring the optical susceptibility Ξ(5) by degenerate four-wave mixing

High-order nonlinear optical response of -toluene solutions in the sub-picosecond regime

“…The second-and third-order diffracted signals (±2, ±3) propagating in the directions k 5 = 3k 1 − 2k 2 , k 5 = 3k 2 − 2k 1 , k 7 = 4k 1 − 3k 2 and k 7 = 4k 2 − 3k 1 correspond respectively to six-and eight-wave mixing processes which in general should be related to the fifth-and the seventh-order nonlinear susceptibilities χ (5) and χ (7) . However, as has been reported by Chemla et al 1982, Acioli et al 1990and Schmid et al 1995 these signals can have contributions not only from the direct higher-order processes but also from cascade processes coming from the interaction between the fundamental fields and fields emitted via lower-order processes. Both types of contributing signals are scattered in the same direction and they present the same intensity dependence, therefore these are not easily separated.…”

“….) corresponding to higher-order mixing can also contribute to the signal (Maruani et al 1978, Acioli et al 1990, Schmid et al 1995. These higher-order terms have been observed as higher diffraction orders in various materials such as semiconductor doped glasses (Acioli et al 1990, Schmid et al 1995.…”