为提高变形镜的热稳定性, 提出一种用正电压边缘驱动的双压电片变形镜, 通过环形电极产生整体离焦偏置, 分立电极校正波前像差, 只用正向电压即可实现镜面双向变形, 且此变形镜结构对称受热应力影响小.制备变形镜样机并进行测试, 测试结果表明: 初始镜面展平后残余误差小于λ/30(λ=1 064 nm); 精确重构了典型低阶Zernike多项式像差, 像散、离焦、三叶草和彗差像差的重构幅值分别达到11.1 μm、9.7 μm、5.7 μm和4.2 μm, 归一化残余误差分别为1.0%、1.0%、3.3%、6.0%; 此外, 实验生成了新型无衍射艾里光束, 并显示出优异的重构性能.

To improve the thermal stability of the deformable mirror, a bimorph deformable mirror driven by positive-voltage actuators at edge was proposed. The ring electrode of the deformable mirror was used to generate an overall defocus bias, while the discrete electrodes were used to correct the wavefront aberrations. The bidirectional deformation of the mirror can be realized by the positive voltage only, and the thermal deformation of the deformable mirror was low due to the symmetrical structure. The deformable mirror prototype was fabricated and tested. The test results show that the residual error of mirror surface after flattening is less than λ/30 (λ=1 064 nm). The typical low-order Zernike mode aberrations, such as astigmatism, defocus, trefoil and coma, are accurately reconstructed. The reconstructed amplitudes are 11.1 μm, 9.7 μm, 5.7 μm and 4.2 μm, with the normalized residual errors of 1%, 1%, 3.3%, and 6%, respectively. In addition, non-diffraction Airy beam is generated experimentally, which shows the excellent reconstruction performance of the deformable mirror.