Abstract

We have studied non-degenerated Stokes four-wave scattering of light by coherently excited polaritons in a non-centrosymmetric crystals. This type of parametric interaction is usually treated as a cascade process consisting of the two stages In our case, it could be described as two sequential processes of the frequency subtraction Polariton wave with the frequency ω_p=ω₁-ω₂ is excited at the first stage. ω₁ and ω₂ are the frequencies of the pumping waves belonging to the near IR range of spectrum. Visible "probe" beam with the frequency ω_L is scattered by the driven polariton wave at the second stage. The intensity of the scattered radiation with the frequency ω_s= ω_L-ω_p is proportional to (χ⁽²⁾)². Here χ⁽²⁾ denotes quadratic susceptibility of a medium.

© 1998 IEEE