Measurement of the target surface temperature in the presence of a laser-induced plasma

Abstract

A new pyrometric method was used to measure the evolution of the surface temperature of a metallic target at the end of a powerful laser pulse. The method uses the property of a metallic surface to polarize the reflected and emitted lights in different ways. Surface temperatures in the range 2000-5000 K were measured through the strongly radiative plasma

Utility of optical heterodyne displacement sensing and laser ultrasonics as in situ process control diagnostic for additive manufacturing

“…4,5,7,8 Some methods that have been employed, albeit not all, are in situ. The techniques include the use of interference of reflected light, 19 x-ray diffraction, 20 coherent Raman line shift spectroscopy, 21 thermionic emission, 22 time of flight, 23 ellipsometry, 24 and electron diffraction if crystalline phases are present, 25 and pyrometry. 26 Notwithstanding these techniques, we recently published a noncontact in situ approach that tracks the change in local temperature near a fusing/sintering zone.…”