Effect of temperature on the absorption coefficient of water for Ho:YAG laser light

The dynamics of the water absorption peak around 1.94 micrometers was examined. This peak is important for the absorption of holmium and thulium laser radiation. To examine the effect of temperature on the absorption coefficient, the transmission of light through water of 22, 49 and 70 degree(s)C was measured from 1850 -2150 nm with a spectrophotometer. It was found that the absorption peak at 1.94 micrometers (at 22 degree(s)C) shifts to shorter wavelengths with increasing temperatures, to 1.92 micrometers at 70 degree(s)C. It was also seen that the absorption peak increases slightly with increasing temperature. It is shown in this paper that the dynamics of the absorption coefficient has a significant influence on the expected zone of damage and ablation parameters in the 2 micrometers wavelength range.