Surface temperature evolution in pulsed laser action of millisecond range

摘要

An originally developed multi-wavelength pyrometer (12 wavelengths in the range 1.001-1.573 mu m, 50 mu s acquisition time for each photodiode, 800 mu m spatial resolution, 900-3500 degrees C brightness temperature range) is used to measure brightness temperature under the pulsed action of Nd:YAG laser (HAAS-HL62P) on stainless steel (INOX 304L) substrates. Specially developed "notch" filters (10(-6) transparency at 1.06 mu m wavelength) are applied to avoid the influence of laser radiation on temperature measurements. The true temperature is restored on the basis of method of multi-colour pyrometry. The accuracy of brightness temperature measurements is examined by comparing the temperature evolution for pulses with different durations but with the same value of energy density flux.