Application of BaSO4 Diffuser Plate in 250-400 nm Spectral Radiance Calibration
JIA Hui, LI Fu-tian
State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130022, China
Abstract：Sprayed BaSO4 diffuser plate is the most Lambertian surface actually used in spectral radiance calibration known by now. Its hemispheric reflectance and Bi-directional Reflectance Distribution Functions(BRDF) were measured in the experiment. Its diffuse characteristics were compared with Lambertian surface. In order to calibrate spectral radiance more accurately, the small variation of diffuser’s BRDF with scattered angles and the nonuniformity of spectral irradiance on diffuser surface illuminated by the standard lamp should be considered. By integrating the radiation flux reflected by the element area and that entering the entrance slit within the viewing area of spectrometer, the measured spectral radiance can be calculated. Further more, the spectral radiance of Lambertian surface whose BRDF was derived from hemispheric reflectance was compared with that from the average of the measured BRDF.
[1] 李念曾, 闫达远. 辐射度学和光度学. Beijing(北京): Beijing Institute of Technology Press(北京理工大学出版社), 1990. 46. [2] Young E R, Clark K C, Bennett R B et al. Applied Optics, 1980, 19(20): 3500. [3] Flower W K, Nelson V W. Metrologia, 1993, 30(4): 255. [4] Fegley A A, Flower V K. Metrologia, 1991, 28(3): 297. [5] Renotte E, Novi A, Labate D et al. SPIE, 1996, 2957：355. [6] Barness P Y, Hsia J J. Proc SPIE, 1992, 1764: 285. [7] 王沫然. MATLAB 6.0与科学计算. 北京：电子工业出版社, 2001. 97. [8] 周金萍, 王 冉, 吴 斌. MATLAB 6实践与提高. 北京：中国电力出版社, 2002. 101. [9] 荀 飞编著. Mathematica 4. 北京: 中国电力出版社, 2000. 172.
