Manufacturing and testing of rectangular off-axis aspheric mirror with double-swing polishing method

Abstract

A kind of manufacturing and testing method for rectangular off-axis aspheric lightweight mirror is introduced. In order to overcome the corner effect,double-swing polishing( DSP) method is proposed. A DSP machine is made to achieve satisfying manufacturing result. The DSP and the 4-pole method are successfully applied for manufacturing optical system in the spectrometer. Four rectangular off-axis aspheric mirrors with the largest size of 266 mm × 110 mm are polished,and the final surface precision figures are better than0. 020λ( RMS,@ 633 nm). Manufacturing result shows that the double-swing polishing method improves the polishing efficiency and reduces the optical surface medium frequency error.