Kinetics of the transient optical absorption in Li2B4O7 and LiB3O5 lithium borate crystals

Abstract

This paper reports on a study of the kinetics of electron tunneling transport between electron and hole centers in Li 2B 4O 7 and LiB 3O 5 lithium borate crystals under the conditions where the mobility of one of the partners in the recombination process is thermally stimulated. A mathematical model has been proposed to describe all specific features in the relaxation kinetics of the induced optical density observed in Li 2B 4O 7 (LTB) and LiB 3O 5 (LBO) nonlinear optical crystals within a broad time interval of 10 -8-1 s after a radiation pulse. The results of calculations have been compared with experimental data on transient optical absorption (TOA) of LTB and LBO crystals in the visible and ultraviolet spectral regions. The nature of the radiation defects responsible for TOA and the dependence of the TOA decay kinetics on temperature, excitation power, and other experimental conditions have been discussed. © 2012 Pleiades Publishing, Ltd.