Mirrorless coherent oscillation due to six-beam vectorial mixing in photorefractive crystals

Abstract

A cw mirrorless oscillation is observed in a photorefractive LiNbO(3):Cu crystal when the crystal is exposed to two nearly counterpropagating pump waves from an Ar(+) laser. This oscillation is shown to result from a parametric vectorial six-beam interaction in a medium with a photovoltaic nonlinearity.