Optomechanical analysis of the mounting performance of large laser transport mirrors

Abstract

In the high-power laser facility (SG-III), focusing 48 laser beams into the target center better than 50 microns (RMS) within a few picoseconds is dependent on the stringent specifications of thousands of large optics and also puts huge challenges on the engineering characteristics of the design and mounting. A parametric optomechanical method is proposed to evaluate the performance of a 400 mm large-aperture transport mirror. With theoretical modeling and numerical analysis, the impacts of assembly structure, manufacturing errors, mounting loads, and gravity on the mirror surface aberrations are calculated and discussed in detail. With field experiments and case studies, the proposed method shows a powerful performance on the mirror surface aberrations’ evaluation, and negative impacts of currently used mounting techniques for the mirror are found. Finally, a new assembly design is presented based on a discussion of its advantages.