金属-电介质多层膜结构表面等离激元及PLZT铁电薄膜电光性能研究

PLZT ferroelectric thin films have become the first choice in the field of optical waveguide, electro-optic modulators and high-speed optical phased array devices for its outstanding electro-optical and nonlinear optical and photorefractive effect. However, due to the existence of ferroelectric domains, ferroelectric film modulators generally have lower electro-optic coefficients than bulk material and related application limitations. The latest research shows that interaction between surface plasmon polariton and electro-optic polymer film material will allow for enhanced nonlinear optical properties at low incident light intensities. This finding enable researches associated with the roles of ferroelectric thin film materials in regulating SPPs just cause scholars’ attention. Similarly, study on the transmission characteristics of SPPs utilizing ferroelectric thin films has just started. Therefore, we will study on manipulating Surface Plasmon and electro-optical properties of PLZT ferroelectric thin films. By investigating the changes of electro-optical properties dependent of some parameters such as misfit strain and grain size, we will reveal possible mechanisms for PLZT thin films regulating SPPs transmission characteristics. From differences on the PLZT electro-optical properties of the film before and after irradiation of the pump light, we will propose possible physical mechanism responsible for film high-order electro-optical properties. The project will have an important significance for achieving new light modulator with high speed, low drive voltage and wide modulation bandwidth.

锆钛酸镧铅（PLZT）铁电薄膜因突出的电光、非线性光学和光折变效应而成为集成光学领域光波导、电光调制器和高速光学相控阵的首选材料。然而，铁电薄膜因铁电畴的存在而普遍拥有逊色于块材材料的电光系数和应用方面的局限性。最新研究报道了SPPs与电光聚合物薄膜相作用将使材料在低入射光强下获得增强的非线性光学性质，这使得铁电薄膜材料引起了SPPs领域研究学者的关注。类似地，铁电薄膜材料调控SPPs特性方面的研究至今刚刚起步。因此，申请人提出了金属-电介质多层膜结构表面等离激元及PLZT铁电薄膜电光性能研究。通过研究错配应变和晶粒尺寸等因素作用PLZT薄膜电光性能的变化规律，揭示PLZT薄膜对SPPs传输特性调控的影响机制。通过泵浦光照射前后PLZT薄膜电光性能的差异，提出PLZT薄膜高阶电光性能增强效应的物理机制。本研究将对集成领域实现高速、低驱动电压且宽调制带宽的新型电光调制器有重要的指导意义。

基于铁电薄膜作为电介质能够有利于SPPs激发并且可以显著地影响SPPs的光传输特性，申请人提出了金属-电介质多层膜结构表面等离激元及PLZT铁电薄膜电光性能研究。围绕提出的研究内容，申请人近三年根据研究计划，开展了多方面的课题研究并取得了进展。首先，采用Sol-gel法和磁控溅射方法和快速热处理制备出均匀致密的单晶基底/缓冲层/PLZT外延薄膜/金属组成的多层薄膜材料。研究了化学组分、厚度、温度等因素作用下PLZT/基底外延薄膜微结构对电学性能的重要影响。其次，本项目针对氧化物电极对PLZT薄膜的重要性，开展了大量的实验工艺探索并获得了Al掺杂ZnO电极的优化工艺参数。再次，PFM结果表明了PLZT/PZT薄膜沉积在Nd：SrTiO3（0.7%铌掺杂）单晶具有显著优于Pt/Ti/SiO2/Si多晶的压电性能（优于3倍的压电系数），从纳米畴结构角度分析了PLZT电光薄膜压电系数提高的影响机制。居里温度和热处理情况下，铁电性能的结果表明了PZT薄膜的极化特性与微结构和相结构有直接关系。此外，本项目基于搭建的PLZT薄膜电光系数的测量系统，揭示了PLZT薄膜/AZO薄膜光学性质包括折射率、二次电光系数的变化规律。最后，对于棱镜/金属膜/PLZT多层膜耦合结构中，我们探索了该复合结构中SPPs的色散关系和透射光强度的变化规律。总之，本项目的研究课题将对集成领域实现高速、低驱动电压且宽调制带宽的新型电光调制器有重要的指导意义。