Investigation of scattering of high-power laser radiation in lithium triborate crystals using piezoelectric resonance spectroscopy

Problem formulating. Due to the power scaling of modern laser sources the requirements for the optical quality of nonlinearoptical crystals widely used for radiation frequency conversion are increased. The optical quality of crystals can be characterized by its absorption and scattering coefficients.

Goal. Verification of the possibility of the application of piezoelectric resonance laser calorimetry (PRLC) for measurements of optical scattering coefficients of nonlinear-optical crystals interacting with high-power laser radiation.

Result. A novel approach was introduced for measurements of low optical scattering coefficients of nonlinear-optical crystals using PRLC technique The optical scattering coefficient of lithium triborate LiB3O5 (LBO) crystal interacting with CW laser radiation at 1070 nm was measured. In the intensity range from 3 MW/cm2 to 60 MW/cm2 the scattering coefficient of LBO increased from 1.5∙10–3 cm–1 to 5.0∙10–3 cm–1.

Practical meaning. It was demonstrated that the PRLC technique can be used for measurements of optical scattering coefficients of nonlinear-optical crystals interacting with high-intensity laser radiation.