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Portable high-accuracy non-absorbing laser power measurement at kilowatt levels by means of radiation pressure



Paul A. Williams, Joshua A. Hadler, Frank C. Maring, Robert Lee, Kyle A. Rogers, Brian J. Simonds, Matthew T. Spidell, Ari D. Feldman, John H. Lehman


We describe a unique optical power meter which measures the radiation pressure to accurately determine a laser’s optical power output. This approach traces its calibration of the optical Watt to the kilogram. Our power meter is designed for high-accuracy and portability with the capability of multi-kilowatt measurements whose upper power limit is limited only by the mirror quality. We provide detailed uncertainty evaluation and validate experimentally an average expanded relative uncertainty of 0.016 from 1 kW to 10 kW. Radiation pressure as a power measurement tool is unique to the extent that it does not rely on absorption of the light to produce a high-accuracy result. This permits fast measurements, simplifies power scalability, and allows high-accuracy measurements to be made during use of the laser for other applications.
Optics Express


Radiation pressure, laser radiometry, photon momentum, optical power meter
Created February 16, 2016, Updated November 10, 2018