Abstract: Near stoichiometric Mg∶ Fe∶ LiNbO_3 crystals were grown by top-seeded solution growth method with K_2O as fluxing medium. UV-Vis spectra, IR spectra, photodamage resistance ability and diffraction efficiency are measured. The results show that with the increase of doped Mg, the absorption edge of crystals shift to the violet firstly, and then shift to infrared. The photodamage resistance ability increases, but the diffraction efficiency decreases. The OH- absorption peak is bimodal distribution. Location model of doped Mg, Fe ions are given. [Li]/[Nb] ratio in crystals, attributed indirectly, is about 49.7-49.8%, the threshold concentration of Mg in doped near stoichiometric LiNbO_3 crystals is between 2% and 3%.

Key words: near stoichiometric Mg∶ Fe∶ LiNbO_3%top-seeded solution growth method%photorefractive property