Self-pumped optical phase conjugation with a sodium Raman laser

We report self-pumped optical phase conjugation in which the pumps are self-induced as standing waves in a linear Raman laser. Self-pumped reflectivities approaching 5% are obtained for input intensities of 20 W/cm(2). This low optical input intensity combined with predicted submicrosecond response times suggests that the resonant Raman interaction may provide the basis for a promising new class of nonlinear-optical material.