A pulsed optical characterization of nonlinear lithium borate crystals

We report a study of the spectra and decay kinetics of transient optical absorption (TOA) in crystals of Li2B4O7 and LiB3O5 under excitation with an electron-beam (200 keV, 10 ns). A mathematical model of electron tunneling between trapped electron and hole centers under conditions of their thermally stimulated mobility was developed. These centers are responsible for the unwanted TOA produced in lithium borates at room temperature by highpower pulsed ultraviolet lasers. The paper discusses the origin of short-living defects that determine the TOA, as well as the origin, of the TOA decay kinetics. © 2012 Optical Society of America