Design and optimization of a support system for large aperture wedge prisms based on an integrated opto-mechanical analysis.

Abstract

A stable and reliable support system for large aperture wedge prisms is the priority of the atmospheric dispersion corrector (ADC). The prism is not a rotationally symmetric component, and the stress distribution on large aperture wedge prisms caused by the support system is different compared with the rotationally symmetric mirror. A scheme of support forces passing through the prism center of gravity (COG) is proposed in this paper. Comparing with the scheme of support force passing through the prism geometry center of rotation (COR) under the same conditions, the root-mean-square (RMS) value of the optical surface shape error shows that the proposed scheme obtains better optical surface quality when the prism rotates from 0° to 360° under the conditions of gravity coupling at 2°C and 42°C. In addition, based on the proposed scheme, a multi-island genetic algorithm (MIGA) is used to optimize the position parameters of the supports. The results show that the RMS value of the optical surface deformation of the wedge prism decreases effectively. Under the conditions of gravity coupling at temperatures of 2°C and 42°C, the RMS value decreases from 260.7 nm to 107.8 nm with 58.6% and from 108.6 nm to 69.5 nm with 36.0%, respectively.