【摘要】 针对微变形镜镜面残余应力变形问题,使用数值法分析了多晶硅层和金属层不等面积的双层微机械薄膜残余应力影响下的变形情况,得到了变形-金属膜尺寸的关系曲线,确定了特定应力下最佳的金属反射面大小;此外,还利用弹性系数可变的折叠梁对分立式微变形镜单元的静电力驱动进行了改进,有效地增大了分立式微变形镜的冲程,使其能对近红外光进行校正。更多还原

【Abstract】 Segmented micro deformable mirrors offer advantages in size,weight,speed and performance over the continuous micro deformable mirrors and have tremendous potential in reducing the cost and weight of adaptive optical systems.But existing experimental segmented micro deformable mirrors still suffer from two defects: unacceptable PV(peak-to-valley) value and it is not applicable to infrared spectrum.We aim to present a preliminary solution of the PV value problem and report some progress toward solution of the infrared spectrum problem.In the full paper,we explain in detail our preliminary solution and some progress made;here,we give only a briefing.ANSYS model of bilayer plate is built and the residual-stress-induced out-of-plane deformation of polysilicon plate with patterned gold layer is studied.A biaxial and uniform residual stress is established via an equivalent fake thermal load.The result of numerical analysis shows that under given residual stress of gold layer,there is an optimal gold pad size to get a minimum peak-to-valley mirror flatness that is just about acceptable.Furthermore,in order to expand the stroke or working range of the segmented micro deformable mirror,nonlinear beam is introduced into the structure design of it.Finally,by using already available surface fabrication foundry, the structure design is implemented to realize the segmented micro deformable mirror with a somewhat larger stroke,which is not yet sufficiently large to remove the defect of not being applicable to far infrared spectrum.更多还原