Large diameter optics support optimization based on finite element method and optical surface fitting with Zernike method

Large aperture optical element deformed by its own weight is caused is one of the important considerations when we design the optical system, designing a mirror support solution that reduces the effects of gravity is critical. Traditional methods cannot effectively and intuitively analyze mirror distortion. In this paper, the finite element method and the optical surface fitting with Zernike polynomial are used to optimize the support scheme. These two methods are mutually verified and this method which use two parts is verified by the optimization scheme of the Φ900mm standard spherical mirror. With optimization, the steel belt loading and unloading weight hammer support scheme is finally adopted, and the best solution with Φ705mmin the circumference and each aperture is 55mm on the back of the mirror is obtained. The theoretical mirror surface’s PV and RMS value equal to 7.36nm (1/86λ) and 1.64nm (1/386λ), which is a good basis for guiding production.