Multi-kilowatt cw laser power measurement comparison between NMI standards

Published

February 14, 2024

Author(s)

Kyle Rogers, Paul A. Williams, John H. Lehman, Marco Lopez, Marcel Pastuschek, Holger Lecher, Stefan Kueck

Abstract

We present here the first comparison between National Metrology Institutes (NMIs) of high accuracy continuous wave (cw) optical power measurements in the kilowatt regime. The National Institute of Standards and Technology (NIST) performed measurements with a power meter relying on photon momentum. The Physikalisch-Technische Bundesanstalt (PTB) performed measurements with a modified off-the-shelf thermal power meter. The non-absorbing photon momentum measurement approach permits the two power meters to measure the same laser beam optical path simultaneously. The two devices were used to calibrate a common photodiode monitor detector and report a responsivity to make the comparison. The results show agreement within the expanded uncertainties for each instrument. NIST and PTB illustrate a degree of equivalence of 0.49% with an expanded uncertainty of 1.37% (k=2) for an average result across all power levels.

Citation

Metrologia

Pub Type

Journals

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Keywords

primary standard, radiation pressure, optical power calibration, kilowatt

Citation

Rogers, K. , Williams, P. , Lehman, J. , Lopez, M. , Pastuschek, M. , Lecher, H. and Kueck, S. (2024), Multi-kilowatt cw laser power measurement comparison between NMI standards, Metrologia, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956830 (Accessed October 15, 2025)