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High accuracy laser radiometry is on the verge of growth and improvements just as new laser technologies are evolving. Our present tasks are directed toward anticipating and meeting the measurement needs in two areas: higher power and shorter wavelengths. New technologies include high-power compact laser diode sources and ultraviolet laser sources...
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... high power levels and the size of the arrays can cause large uncertainties with the best commercially available optical radiometers. As an alternative to the isoperibol calorimeter, a flowing water optical power meter (FWOPM) has been developed ( Figure 1). The present embodiment of the FWOPM is a copper cavity with a black coating that captures nearly 2π steradians of the laser output with 99.9 % efficiency. ...
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Citations
RLCYC 75 is a new electrically calibrated laser calorimeter specially manufactured by Laser Metrology to calibrate energy diagnostics within the Laser MegaJoule (LMJ) facility. It consists of an optical cavity cooled by a hydraulic system. The system is designed to provide 1 µm wavelength power laser measurements with uncertainty less than 1% at 2 kW and traceability to the International System of Units (SI). In this paper, the accuracy of RLCYC 75 measurements is studied. More precisely, three points are detailed: instrumentation uncertainty estimation, equivalence between optical and electrical supply and light absorption. To this end, electrical calibration campaigns and power laser measurement campaigns are conducted. Moreover, thermal and optical models are developed. Results show that RLCYC 75 design and instrumentation are efficient enough to reach the goal of relative uncertainty of about 1% at 2 kW. RLCYC 75 will become the 2 kW laser power primary standard for LMJ applications.
