Four-wave mixing in alkali halide crystals and aqueous solutions

Abstract

Noncollinear phase-matched nonresonant four-photon frequency mixing ωp+ωp-ωL→ωs in crystals and aqueous solutions of LiCl, CsCl, KF, and KI is studied. The concentration of the aqueous solutions is varied between 0.5 mol/l and saturation. Picosecond laser pulses of a mode-locked Nd-glass laser are applied as pump pulses. The energy conversion of laser light at frequency ωL to frequency ωS is measured and the nonlinear susceptibilities χ(3) are calculated. The dependence of the hyperpolarizabilities on concentration is analysed and gives information on the solute-solvent interaction. © 1982 Springer-Verlag.