Laser power absorbed outside the beam spot on a rippled metallic surface as determined by a matrix calorimetric method

Abstract
A new modified matrix calorimetric method is presented that allows one to determine, with the use of only one thermocouple, the distribution of power dissipation across an extended heat source. This method allows experimental determination of the fraction of the incident laser power (energy) absorbed on a metallic surface outside an irradiation spot located on a rippled area. It is shown that this fraction can amount to a significant part of the total incident laser power (energy). The effect is important in high-intensity laser irradiation of metals when periodic surface structures are induced within the irradiation spot by action of the laser radiation.