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An infrared laser-based reflectometer for low reflectance measurements of samples and cavity structures



Leonard M. Hanssen, Jinan Zeng


An instrument, the Complete Hemispherical Infrared Laser-based Reflectometer (CHILR), has been designed and built for the accurate characterization of the total reflectance of highly absorbing samples and cavity structures down to the level of 10-5. The design of CHILR employs a number of the same features of Total Integrated Scatter (TIS) measurement devices, but is used for total reflectance (both specular and diffuse components), rather than only the diffuse component. A number of features of CHILR include spatial uniformity and angular dependence of reflectance measurement capability, multiple wavelength laser sources, and the ability to measure a wide range of sample sizes and cavities with aperture sizes, ranging from 3 mm to 100 mm. We will address several basic issues of alignment, background and externally scattered light, reference measurement, and laser drift, for the CHILR. We will present results of several examples, including cavities for blackbody sources, and radiometer cavities
Proceedings Title
Proceedings of SPIE
Conference Dates
August 10-14, 2008
Conference Location
San Diego, CA
Conference Title
SPIE Optics and Photonics Conference


blackbody cavity, Complete Hemispherical, gold-coated integrating sphere, indirect emissivity, Infrared Laser-based Reflectometer, low reflectance measurement, OPO tunable laser, radiometer cavity, stabilized CO2 laser


Hanssen, L. and Zeng, J. (2008), An infrared laser-based reflectometer for low reflectance measurements of samples and cavity structures, Proceedings of SPIE, San Diego, CA (Accessed July 14, 2024)


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Created September 15, 2008, Updated February 19, 2017