为了提高用于天文自适应光学系统的单压电变形镜的校正能力,提出了一种直径为75 mm且包含214个单元的带边缘驱动的单压电变形镜,单压电变形镜的边缘由数个压电堆栈执行器支撑.首先,通过有限元方法对变形镜进行仿真建模,分析比较三点、六点能动支撑对变形镜性能的影响.之后制备了三点、六点边缘驱动的变形镜样机.最后,利用波前传感器测试了边缘执行器对低阶像差的校正能力.实验结果表明:在0~100 V电压下,三点能动支撑与六点能动支撑变形镜均可重构大于12μm的倾斜像差,对应的归一化残余误差小于0.06,六点致动对像散和三叶草像差也具有较好的校正能力,证明边缘执行器可提高单压电变形镜的校正能力.
In order to improve the performance of unimorph deformable mirror for astronomical adaptive optics applications,an unimorph deformable mirror with edge-driven was proposed.The unimorph deformable mirror has a 75 mm diameter and 214 elements,which is supported by several piezoelectric stack actuators at the edge.First,the structural model was established using finite element method.The performances of unimorph deformable mirrors with three and six active supports were analyzed and compared.Then,a three points edge-driven unimorph deformable mirror and a six points edge-driven unimorph deformable mirror were fabricated.Finally,the correction performance of the supporting actuators for low aberrations was tested using a wavefront sensor.The experimental results show that,the unimorph deformable mirrors with three and six supporting actuators can reconstruct tip and tilt aberrations which are greater than 12 μm under 100 V operating voltage with normalized residual error less than 0.06.Six supporting actuators also have a good correction capability for astigmatism and trefoil aberrations.It is proved that the supporting actuators at the edge can be used to improve the correction capability of the unimorph deformable mirror.