1. Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
Abstract：To correct astigmatism of UV high-resolution Rowland grating for influencing the image height broaden, a train of thought is proposed, which is based on an asymmetric exposure ofthe spherical wave at the Rowland circle. First of all, applying Rowland grating’ｓ aberration expressions derive the defocus and meridian coma full corrected equations. From these equations, a variety of limitations of Rowland grating record structure is discussed, which proves to be a suitable method for the optimization of UV high-resolution Rowland grating. Then, by the vertical ray deviation’s expression in the image plane, the paper refer to the astigmatism and sagittal coma as the principal factor to spectrum image-height, which is allocated the weight of aberration coefficients distribution. Taking advantage of this optimization thought, the waveband 110～200 nm，UV high-resolution Rowland grating is design. Meanwhile a series of contrastive analysis for the traditional grating and astigmatism correction Rowland grating, such as the variation tendency of aberration coefficients and spectrum image-height，image structure and spectral resolution. The results indicate, that in the same order of the spectral resolution, astigmatism correction Rowland grating spectral’ｓimage-height isreduced by 25 to 1.5 mm, spectrum energy is more concentrated.
Key words：Rowlandgratings; Astigmatism correction; Design method of gratings
