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As the thickness of the adhesive layer between the mirror and the actuator decreases and the performance requirements of the unimorph deformable mirror (DM) increase, stricter control on the adhesive layer thickness and Young’s modulus is necessary. In this paper, a finite element model (FEM) for the unimorph DM with an adhesive layer is obtained. Based on the model, the influence of adhesive layer thickness and Young’s modulus on the deformation is studied. Also their influence on the adhesive’s maximum shear stress is analyzed. In the meantime, the design principles of the adhesive layer thickness and Young’s modulus are established with the restrictions of shear failure and the maximum displacement. As a result, different adhesive Young’s modulus has corresponding requirements for the upper and lower thicknesses (<20 μm) to obtain 85% maximum displacement. Then, DMs with four different mirror thicknesses are fabricated for verification experiments. The experiments results can be matched with the simulation results. Finally, the thickness in the spin coating process of adhesive layer is explored. The adhesive layer thickness can be controlled within 12.1 μm, and the deviation of uniformity is better than ±2%. [ABSTRACT FROM AUTHOR]

Smooth polishing has a good improvement on the medium and high frequency errors of the workpiece, but the surface accuracy of the workpiece will be damaged subsequently. Therefore, a nonlinear compensation method is proposed. The realization mechanism, mathematical model and compensation effect of nonlinear compensated smooth polishing are illustrated separately and verified by experiments. In addition, the process parameters and motion trajectory are optimized by theoretical simulation. The experimental results demonstrate that the full-band error of the workpiece can be improved simultaneously by the smooth polishing method based on nonlinear compensation. The number of iterations for the figuring experiments and smooth polishing is greatly reduced by the nonlinear compensation model, which is significantly beneficial to improve the surface convergence speed and lower the manufacturing cost. • Mathematical model of nonlinear compensation is developed. • The full-band error of the workpiece is converged. • Toolpath is optimized. • Process parameters are optimized. [ABSTRACT FROM AUTHOR]

Various items of roll molds are popularly used to fabricate different kinds of optical films for optoelectronic information and other new and high-tech fields, while the fabrication and evaluation of optical microstructures on the cylindrical roller surface is more difficult than ecumenic manufactured products. This paper investigates the machinability of microstructures on the roll based on a fast tool servo (FTS) system. First, the flexible hinge holder for FTS is designed and its structure parameters are optimized with finite element analysis and fatigue reliability theory. Then the tool radius compensation algorithm for complicated microstructures is deduced based on the surface fitting and bilinear interpolation algorithm of discrete data. Meanwhile, the evaluation index and method are proposed by the medium section method. Finally, a machining test of aspheric arrays on aluminum cylindrical surface is carried out, and the high quality of the microstructure indicates that the proposed method is able to fabricate optical microstructures. [ABSTRACT FROM AUTHOR]