压电薄膜自适应变形微反射镜阵列研究

Research on PZT-based Deformable Micro-mirror Array in Adaptive Optics

介绍了自适应光学系统中的一种全新的基于Pb(ZrxTi1-xO3)(PZT)薄膜的微反射镜阵列。通过控制PZT薄膜两端电压实现微镜单元的微量形变,改变反射镜局部面形,校正畸变波面的波差,改善成像质量。该方案在重掺杂Si片基底上依次制备PbTiO3(PT)、PZT,最后镀Al作为反射面,形成Si/PT/PZT/Al的膜层结构。对制备完全的试片在数字波面干涉仪上进行了形变测试,尽管受到了薄膜热形变作用的影响,仍实现了约1.2μm的可控形变,证明该方案用做自适应变形反射镜的可行性。

A novel deformable micro-mirror array based on the converse piezoelectric effect of PZT Pb（ZrxTi1-xO3） thin films is introdced. In this way,we choose the heavily doped silicon chip as the substrate,lead titanate （PbTiO3 ,PT） as the buffer layer,lead zirconate titanate （PbZrxTi1-xO3,PZT） as the deformable layer and aluminum（Al） as the reflection surface. The layer structure of Al/PZT/PT/Si is realized. The thickness of PZT thin film varies according to the applied voltage,which makes the unit of micro-mirror array deform and changes the partial surface shape of the mirror. The distorted wavefront and aberration is corrected and the image quality is improved. Although the test is complicated by thermal expansion of the film, tbe deformation measurement is carried out in the interferometer. About 1.2 μm controllable deformation is realized. The testing result proves the practicability of applying PZT thin film in the configuration of deformable micro-mirror in adaptive optics.