Abstract
An optical power calibrator is described whose overall calibration uncertainty is less than 10/sup -4/ for an optical power of 0.13 mW. The laser light source of the system operates at a wavelength of 543.5 nm, being close to the wavelength at which the candela is defined, 555 nm. A stable optical power is achieved by stabilizing the intensity and the frequency of a green He-Ne laser. The optical power is detected by a cryogenic absolute radiometer based on the principle of electrical substitution radiometry. It can be used to measure up to 0.5 mW in the visible and near-infrared region with a 3 sigma uncertainty of about 5*10/sup -5/. The factors limiting the overall uncertainty of the calibrator are analyzed: the conductance fluctuations of the temperature sensor in the absorption cavity and the beam scatter are found to be the most significant error sources. Limited absorptivity of the cavity (0.99998) and the background radiation cause additional uncertainty. The system is controlled by a microcomputer with self-check and autocalibration features.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IEEE Transactions on Instrumentation and Measurement
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
