Lattice vibration modes and thermal conductivity of potassium dihydrogen phosphate crystal studying by Raman spectroscopy

Potassium dihydrogen phosphate (KDP) crystal was grown from solutions in the presence of doping ethylenediamine tetra acetic acid (EDTA) in the concentration range of 0–100 ppm. Its Raman spectra were measured at room temperature with different geometrical configurations. On the basis of the group theory and lattice dynamics theory, all the Raman peaks were assigned, and a correlation between thermal conductivity and the Raman scattering strength was presented. The calculated thermal conductivity enhancements agree well with experimental enhancement of laser damage threshold, which indicates that the laser damage is a result of local thermal damage of KDP crystals.