光扇效应对Ce:KNSBN记录偏振组态的影响  

Fanning Effect on Writing Beam Polarization Configuration in Ce∶KNSBN Crystal

作　　者：张金平[1] 郭庆林[1] 魏艳红[1] 怀素芳[1] 傅广生[1] 

机构地区：[1]河北大学物理科学与技术学院,保定071002

出　　处：《光学学报》2004年第3期309-312,共4页Acta Optica Sinica

基　　金：河北省自然科学基金 (10 10 5 9);河北省教育厅博士基金(20 0B10 3)资助课题

摘　　要：在非同时读出条件下 ,采用Ar+ 5 14 .5nm单色激光为光源。以信号光为非寻常偏振光 (e光 ) ,通过改变抽运光的偏振态 ,研究不同写入光偏振组态下Ce∶KNSBN晶体的两波耦合特性。结果表明 :由于光扇效应的影响 ,信号光和抽运光同为e光时并非如预测的那样为最佳记录偏振组态。在信号光和抽运光与晶体表面法线呈θ =11°角对称入射下 ,当抽运光的偏振方向与e光偏振方向呈 30°角时 ,光扇噪声得到明显抑制 ,两波耦合增益最大。其原因是抽运光的o光分量对光扇散射光起到了非相干擦除 ,使两波有效耦合得到提高。The Ar + 514.5 nm laser beam is used at non\|simultaneous writing\|reading process. As the signal beam is with extraordinary polarization and the polarized direction of the pump beam has an angle Ψ with its extraordinarily polarized direction, the two wave coupling property of a Ce∶KNSBN photorefractive crystal is experimentally studied. Because of the effect of the fanning, the polarization configuration that both the signal beam and pump beam are with extraordinary polarization is not as optimized as it is expected. As the angle θ\% between the signal beam and the normal of the crystal face takes 11°, the gain of the signal beam reaches its maximum and the fanning noise is depressed greatly. while Ψ=30°,those can be explained that the ordinary component of the pump beam as an incoherent beam erases the fanning and the gain of two\|wave mixing is enhanced.

关 键 词：信息光学 光折变晶体 光扇效应 两波耦合 偏振组态 抽运光 信号光 光全息存储 光学信息处理 钾钠铌酸锶钡晶体 

分 类 号：O734[理学—晶体学] O438[机械工程—光学工程]