DETERMINATION OF THE TEMPERATURE-DEPENDENCE OF THE FREE CARRIER AND INTERBAND ABSORPTION IN SILICON AT 1.06 MU-M

Simultaneous determinations of the free-carrier absorption cross-section, the interband absorption coefficient, and the surface reflectivity, at the Nd:YAG laser wavelength 1.06 mu m and in the temperature interval 195-372K are reported, using a method developed previously. The influence of the free-carrier absorption is described by an analytical model which fits the experimental data very well. The values of the interband absorption coefficient measured with short high-intensity laser pulses agree with the literature values measured at low intensity. The free-carrier absorption cross-section sigma was found to be proportional to the absolute temperature, sigma = sigma n+ sigma p=1.7*10-20 T cm2.