为了满足天文望远镜自适应光学系统的需要，研制了一个961单元的变形镜及其控制系统。利用Zygo激光干涉仪对变形镜的性能进行测试，包括单个促动器的响应测试、相邻促动器间推拉测试、耦合测试；对于变形镜的校正能力，分别进行了Waffle模式测试、Zernike多项式拟合和展平测试。测试表明，961单元变形镜在单个促动器作用下的最大面形校正量为±2.5 μm；相邻促动器间推拉变形量为4 μm；相邻促动器间的耦合为23%；相对于之前的137单元变形镜，其对Zernike多项式的拟合能力有较大地提高；展平后的面形优于λ/70（λ=632.8 nm）。测试结果达到了天文望远镜自适应光学系统对变形镜的性能指标要求。

A 961-element deformable mirror (DM) and its control system are developed to satisfy the demand of the adaptive optical system of the astronomical telescope. The performance of the deformable mirror is tested by Zygo interferometer. Three tests are carried out, which include the response function test of individual actuator, the push-pull capability test of the neighbor actuators and the coupling test between two actuators. Then, the correction capability of the deformable mirror is tested by performing the Waffle mode test, Zernike polynomial fitting test and flattening test. The testing results show that the max correction ability of the deformable mirror actuated by individual actuator is ±2.5 μm. The inter-actuator stroke is 4 μm. And the coupling between two neighbor actuators is 23%. Compared to the former 137-element deformable mirror, the fitting capability of the Zernike polynomials of the 961-element deformable mirror is much better. The surface flatness of the deformable mirror after flattening is better than root-meat-square (RMS) value of λ/70 (λ=632.8 nm). The test results satisfy the requirements of the deformable mirror which is to be used in the adaptive optical system of the astronomical telescope.