Model Design and Stray Light Suppression Technology of Stray-Light Testing Equipment for Plane Grating
ZHAI Shan-shan1, 2, YANG Jin1, 2, Bayanheshig1*, CUI Ji-cheng1, QI Xiang-dong1, TANG Yu-guo1
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:Grating scatter is an important performance index for plane grating, and its measurement is a difficult problem for grating research field. In order to achieve stray-light of the instrument itself to be less than 10-8 so that the grating scatter can be accurately measured, stray light in diffraction grating monochromators has been studied and an opto-mechanical model of measure instrument for plane grating is designed, which works in parallel light environment and based on the scalar diffraction theory and classical Fresnel-Kirchhoff diffraction theory. Main pathway of the instrumentation’s stray light is calculated and analyzed by the simulation of stray-light testing equipment with ASAP software. Accordingly, four stray-light suppression structures including blocking rings, vanes, aperture stops and light traps are proposed to reduce instrument’s scattered light and grating’s multiple diffraction. Finally, contrast analysis of the instrumentation’s stray light is made before and after adding stray-light suppression structures. Simulation and analysis results show that the max of instrument’s stray light reduces from more than 10-6 to less than 10-8 after adding stray-light suppression structures and has met the stray-light testing equipment’s design requirements whose goal is to realize accurate measurement greater than or equal to 10-7 for grating scatter with grating’s groove density changing from 300 to 3 600 gr·mm-1. The research methods and results above will provide a theoretical basis for the research and development of the stray-light testing equipment for plane grating.
[1] ZHU Shao-ji, ZOU Hai-xing, BAO Xue-cheng, et al(祝绍箕,邹海兴,包学诚, 等). Diffraction Grating(衍射光栅). Beijing: China Machine Press(北京:机械工业出版社), 1988. 343. [2] Asmail C C, Cromer C L, Proctor J E, et al. SPIE, 1994, 2260 Stray Radiation in Optical Systems III: 52. [3] Christopher Palmer. Newport Corporation,2005, Sixth Edition: 41. [4] Jakob Neubert, Thomas Seifert, Norbert Czarnetzki, et al. SPIE, 2210: 543. [5] Thomas N Woods, Raymond T Wrigley III, Gary J Rottman, et al. Applied Optics, 1994, 33(19): 4273. [6] Ivan G Kuznetsov, David A Content, Rene A Boucarut, et al. SPIE, 2002, 4485: 417. [7] ZENG Guang-jie, SHEN De-hong(曾广杰,沈德洪). GUANGYI JISHU(光仪技术), 1992, 13(4): 9. [8] SHEN De-hong, ZENG Guang-jie(沈德洪,曾广杰). Acta Metrologica Sinica(计量学报), 1990, 11(1): 7. [9] Bayanheshig, LI Yan, WU Na, et al(巴音贺希格,李 燕,吴 娜,等). Optics and Precision Engineering(光学 精密工程), 2009, 17(8): 1783. [10] Sharpe M R, Irish D. Optica Acta, 1978, 25(9): 861. [11] Breault Research Organization. ASAP<sup>TM</sup> Technical Guide, 2003, Scattering: 7. [12] Sholl M J, Grochocki F S, Fleming J C, et al. SPIE, 2007, 6675:66750C1-12. [13] LI Xiao-ping, SHA Sheng-chun, HU Ting-liang(李晓平,沙晟春,胡亭亮). Optics and Precision Engineering(光学 精密工程), 2011, 19(11): 2603. [14] JIN Yu-xi, HUANG Mei-zhen, WU Ping, et al(金玉希,黄梅珍,吴 平,等). Journal of Shanghai Jiaotong University(上海交通大学学报), 2011, 45(11): 1602.