用于WDM的多重体光栅曝光方法及层状体全息光栅的研究

本文针对层状多重体全息在红外通讯波段分光滤波的应用,分析了其布喇格匹配与衍射效率均匀性问题.给出了在LiNbO3∶Fe光折变晶体中制作层状多重体全息光栅的几种方法.利用双片光干涉在直接分层结构中写入了三层光栅,光栅层厚1 mm,层间距2 mm,每层复用了四个光栅.对这三层光栅的分析测试表明,12个光栅的衍射效率均匀,相邻通道间隔约3 nm.实验结果表明,这种层状结构的多重体全息光栅有希望用来组成具有大量通道数的WDM系统中的复用/解复用器件.

Recording Method and Fabrication of Layered Multiple Volume Holographic Gratings for WDM

For application to optical telecommunication band of layered multiple volume holographic gratings (VHG),the issue of Bragg match and the uniformity of diffraction efficiency are analyzed.Several approaches to fabricate multiple layered VHGs in LiNbO3∶Fe crystal are illustrated.Three layer gratings with 1 mm thickness,2 mm space and four gratings superimposed in each layer were written in a LiNbO3∶Fe crystal by employing angle and space multiplexing techniques via two sheet beams interference.Measurement and analysis shows that twelve gratings in three layers with homogeneous diffraction efficiency and about 3 nm channel space were obtained.