Determination of the absorption length of CO₂ and high power diode laser radiation for a high volume alumina-based refractory material

The laser beam absorption lengths of CO₂ (10.6 μm wavelength) and a high power diode laser (HPDL) (810 nm wavelength) radiation for an Al₂O₃/SiO₂-based refractory have been determined through the application of Beer-Lambert's law. The findings revealed marked differences in the absorption lengths despite the material having similar beam absorption coefficients for both lasers. The absorption lengths for the Al₂O₃/SiO₂-based refractory of CO₂ and a HPDL radiation were calculated as being 345±22 and 198±15 μm, respectively. Moreover, this method of laser beam absorption length determination, which has hitherto been used predominantly with lasers operated in the pulsed mode, is shown to be valid for use with lasers operated in the continuous wave (CW) mode, depending upon the material being treated.