Two-beam coupling measurements of anisotropic volume gratings in chromium-doped potassium niobate crystal

Abstract Empty traps concentration, the sign of the dominant photocarriers and the effective electro-optic coefficient in chromium doped potassium niobate single crystal using steady-state beam coupling at 532 nm, have been measured. A density of 0.7×10 −16 cm −3 of positive photocarriers, r eff =20 pm/V and 〈 κ 〉=0.25 are obtained. To explain these results, anisotropic photoexcitation cross section of mobile charge carriers has to be considered.