Design and analysis for the Multi-point flexible support structure of large and precision lens

Abstract In order to achieve accurate surface figure and optical axis stability of a large aperture lens in the ground-based telescope system which subject to various load case, a novel lens support with multi-point flexible support structure is proposed. Then, the parameters of the support structure are optimized based on low-order modal and system accuracy, and the sensitivity of the flexure element’s parameters, the impact on the optical axis inducted by assembly and machining error of the support structure and the stability of the lens under different load cases are analyzed, meanwhile the rigidity of the support structure is tested. The result show that: the support rigidity of the system is higher, the optical axis offset causing by gravity is less than 2μm when the lens is mounted horizontally; lens wave-front aberration (RMS) is 11.07nm when thermal load is altered from reference temperature(+20°C) to -20°C. The results and practice indicate that the multi-point flexible support structure can improve lens surface figure, and the assembly design is practicable and extensible.