For precision optical systems such as lithographic projection objective, the mechanical structures are required to keep the optical lenses in their exact spatial positions accurately and reliably in order to maintain the precise surface figure of the optical elements. At the same time, the mechanical mechanisms are applied in the precise spatial position adjustment of specific optical elements, so as to meet the requirements of systematic integration and online functional compensation of the objective lens system. 

Aiming at the research and development of IC lithography projection objective, the team has successfully overcame the ultra-precision structure design of the single optical element and high-precision integration technology, the high-precision large-diameter curved diaphragm design technology, the ultra-precision axial and lateral adjustment mechanism design and manufacturing technology, and the ultra-precision six-degree-of-freedom adjustment mechanism design and processing technology. The surface figure accuracy of the optical element after integration is better than 1 nm (RMS), and the movement precision of the adjustment mechanism is better than 20 nm.