SINGLE CELL BRILLOUIN ENHANCED 4-WAVE-MIXING WITH FOCUSING GEOMETRY

The generation of a phase conjugated single by single cell Brillouin enhanced four-wave mixing with focusing geometry is reported. A single cell containing the optical nonlinear medium is used simultaneously for conventional stimulated Brillouin scattering and for four-wave mixing. Experiments were performed using both CS2 and TiCl4 as the nonlinear medium. These materials have large Brillouin pin but differ greatly in their nonlinear index of refraction, thus the mechanism for four-wave mixing is shown to be due to the Brillouin nonlinearity. An important advantage of this geometry is that the frequency of the phase conjugate signal is not shifted from the input pump frequency. Although these experiments were performed with a relatively low pump/probe ratio, the energy of the generated phase conjugate signal is the same order of magnitude as that generated under much higher pump/probe ratios.