Photorefractive properties of Mn doped K_(3)Li_(2)Nb_(5)O_(15) crystal

摘要

KLN(K_(3)Li_(2)Nb_(5)O_(15), KLN) and Mn:KLN crystal was grown by Czochralski method. Compared with KLN, the absorption edge of Mn:KLN crystal shifted to infrared band. No correlative property data of KLN was obtained for its weaker photorefractive effect. However, the photorefractive effect of Mn:KLN was enhanced because Mn~(2+) or Mn~(4+) existed in the crystal, which applied more donor and acceptor centers. The two beam coupling coefficient Γ of Mn:KLN crystal with the thickness of 2 mm was up to its maximum value 0.7 cm~(-1) at the external angle of 40°, whereas that of the crystal with the thickness of 0.8 mm was up to its maximum value 1.4 cm~(-1) at the external angle of 34°. The response time decreased with the increasing of pump intensity I_(p). The response time of Mn:KLN was just several seconds, which was one order of magnitude faster than that of Fe doped LiNbO_(3) crystal.