Improvement of photorefractive properties in Hf:Fe:LiNbO_3 crystals with various [Li]/[Nb] ratios

作     者：孙秀冬 石宏新 骆素华 孟庆鑫 姜永远 

作者机构：Department of PhysicsHarbin Institute of Technology 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2010年第19卷第9期

页      面：416-419页

核心收录：

学科分类：08[工学] 0803[工学-光学工程] 

基　　金：supported by the Fundamental Research Foundation of Commission of Science Technology,Industry for National Defense of China (Grant No.2320060089) and National Basic Research and Development Program of China (Grant No.2007CB3070001) Program of Excellent Team in Harbin Institute of Technology,China 

主　　题：diffraction efficiency recording sensitivity Hf:Fe:LiNbO3 crystals 

摘      要：Photorefractive properties of Hf：Fe：LiNbO3 crystals with various [Li]/[Nb] ratios have been investigated at 488 nm wavelength based on the two-wave coupling experiment. High diffraction efficiency and large recording sensitivity are observed and explained. The decrease in Li vacancies is suggested to be the main contributor to the increase in the photoconductivity and subsequently to the induction of the improvement of recording sensitivity. The saturation diffraction efficiency is measured up to 80.2%, and simultaneously the recording sensitivity of 0.91 cm/J is achieved to in the Hf：Fe：LiNbO3 crystal grown from the melt with the [Li]/[Nb] ratio of 1.20, which is significantly enhanced as compared with those of the Hf：Fe：LiNbO3 crystal with the [Li]/[Nb] ratio of 0.94 in melt under the same experimental conditions. Experimental results definitely show that increasing the [Li]/[Nb] ratio in crystal is an effective method＇for Hf：Fe：LiNbO3 crystal to improve its photorefractive properties.