Absorption coeffcient of alumina

[bhartish]

Main Question or Discussion Point

I am solving a temperature distribution problem related to laser drilling. In the equation I am encountering a term called ' Absorption or extinction coeffcient' of alumina. Can anybody tell how to find this ?

 

[Astronuc]

One may wish to read this article:
Abrupt Increase of the Absorption Coefficient of Alumina at Melting by Laser Radiation and Its Decrease at Solidification
Vadim A. Petrov
International Journal of Thermophysics (impact factor: 0.95). 04/2012; 30(6):1938-1959. DOI:10.1007/s10765-009-0678-z

"The importance of kinetics in the abrupt change of the absorption coefficient of molten Al2O3 is noted. "

Meanwhile, there is a discussion of extinction coefficient here:
http://www.emtinc.us/images/Sapphire_vacuum_UV.pdf [Broken]