Five-wave mixing omega(b) = omega(1)+omega(1)+omega(1)-omega(2) in the bulk of a chiral liquid

We propose a theory of wave generation at a frequency ob in the bulk of an isotropic gyrotropic medium by two non-collinear Gaussian beams of fundamen tal radiation with the frequencies omega(1,2). The calculations are made wi th allowance for linear optical rotation of the medium in the case where th e dimensions of the efficient-generation volume are much smaller than the d iffraction lengths of the intersecting beams. Analytical expressions for th e spatial distribution of the field and the total power of a signal wave at the frequency wb were obtained. The spatial dispersion of the optical resp onse of the medium is found to have a distinct effect on the shape of the p hase-synchronism curves, and to lead to the signal wave becoming elliptical ly polarized even under linear polarization of the fundamental waves. It wa s revealed that the dependence of the signal power on the polarization stat es of the fundamental waves changes substantially when the optical rotatory power of the medium increases, On the basis of the experimental data avail able, an estimation was made of the magnitude of the fourth-order non-linea r optical susceptibility in the specific case of second harmonic generation in an aqueous arabinose solution. Copyright (C) 2000 John Wiley & Sons, Lt d.