关键词: 铌酸锂晶体;化学计量比;晶体生长

Abstract: Lithium niobate(LiNbO3) crystal is a kind of typical non-stoichiometric crystal,and generally used one is congruent crystal with ［Li］/［Nb］ ratio of about 48.6/51.4.In this paper,we report that near-stoichiometric LiNbO3 crystal is grown with Czochralski method from a congruent melt with addition of 11mol; K2O.In comparison with congruent one,the position of absorption edge moves to short wave,Ramam linewidth decreases from 9.4cm-1 to 7.0cm-1 for the E mode(153cm-1) and from 25.5cm-1 to 20.0cm-1 for the A1 mode (876cm-1).Its phase-matching temperature for 1064-532nm second harmonic generation increases from room temperature to 155.5℃ and its OH- infrared absorption band is changed distinctly in shape.The linewidth also becomes greatly narrower.According to these measurements,the lithium oxide content in crystal can be estimated to be about 49.6mol;,which is closed to the ideal stoichiometry of LiNbO3 crystal.