Growth and photorefractive properties of Mn-doped (KNa)_0.1(Sr_0.6Ba_0.4)_0.9Nb ₂O₆ crystals

(KNa)_0.1(Sr_0.6Ba_0.4)_0.9Nb ₂O₆, or KNSBN, crystals have been grown with two different Mn concentrations: 0.02 wt % and 0.04 wt %. Two-wave mixing and self-pumped phase conjugation experiments were carried out on these crystals at 632.8 nm wavelength. The measured two-wave coupling gains for the 0.02 wt % and 0.04 wt % crystals are larger than 7 cm^-1 and 9 cm^-1, respectively, and the two-wave coupling time response is faster for the 0.4 wt % crystal. In addition, the self-pumped phase conjugation reflectivity of the 0.04 wt % crystal is measured to be as high as 70%. It is shown that the Mn dopant can increase effectively the absorption coefficient and enhance the photorefractive properties of KNSBN.