Laser Power Estimation by Mass Ablation for High Power Laser

This paper reports an alternative method for estimation of laser power generated from high power carbon dioxide gas dynamic laser. An unstable resonator was employed for generation of laser. In this method an array of thin MS plates separated by an air gap is used for estimation of ablated mass from the array. High power laser beam was focused on the array by concave mirror of long focal length. A fraction of beam is absorbed by the surface which is opaque to laser wavelength @ 10.6 micrometers. The interaction of high power laser beam with array results in temperature rise of MS plates. If laser irradiation is continuous a phase change of material takes place in the array. In the array, 20 plates of mild steel got damaged by irradiation of laser beam and mass are removed by ablation. The paper also describes the development of software for estimation of laser power from ablated mass from each plate. The results are validated by measuring the laser power by a power meter. These results are in agreement with estimated power within +/- 10% of power measured by power meter/calorimeter.