An instrument used to measure the normal specular reflectance of curved optical surface made with transparent material is presented. Instead of the half mirror, i.e. the mirror with 50% reflectance that was commonly used in the previous spectral reflectometers, a specially designed patterned mirror is introduced that can reduce the optical energy loss due to half mirror as many as 50%. The signal-noise rations of the instrument are significantly improved especially in the UV spectrum range. The interference reflection of back surface of the optical components can be effectively prevented by the conjugated optical design. The diameter of measurement spot size in the test surface is about 60 micrometer and the repeat accuracy of measurement results is better than ±0.01% over wavelength 410-700nm.

Date Published: 26 January 2009
PDF: 8 pages
Proc. SPIE 7156, 2008 International Conference on Optical Instruments and Technology: Optical Systems and Optoelectronic Instruments, 71560B (26 January 2009); doi: 10.1117/12.807105

Published in SPIE Proceedings Vol. 7156:
2008 International Conference on Optical Instruments and Technology: Optical Systems and Optoelectronic Instruments
Yunlong Sheng; Yongtian Wang; Lijiang Zeng, Editor(s)