<title>Decrease in the uncertainty of laser radiation average power measurement with the aid of discrete Fourier transform</title>

Abstract

In this paper, a method of increasing the accuracy and sensitivity of optical radiation average power measurements with the aid of a black body (BB) is proposed and studied experimentally. The essence of the method consists in matched Wiener filtration of the results of measuring the kinetics of BB heating up with the aid of the discrete Fourier transform and the method of least squares when the Fourier spectra of the process under study are compared with a model spectrum. The Fourier spectrum of BB heating up at high levels of optical radiation power (when the BB temperature drift can be neglected) is used as the model one. A decrease in the total uncertainty by a factor of 3 to 5 has been attained at low levels of optical radiation power.