Laser-damage threshold of optical components based on lithium triborate (LBO) overview

Owing to the continuous advancement in laser technology, lithium triborate (LBO) has emerged as a widely used nonlinear frequency-doubling crystal in high-power laser systems. Optical thin films are typically applied to the surfaces of LBO crystals to mitigate energy losses caused by Fresnel reflections. However, the laser-induced damage thresholds of both LBO crystals and films deposited on their surfaces typically limit the maximum output power of laser systems. This paper comprehensively reviews several decades of studies on LBO crystals and films deposited on their surfaces. In particular, it includes an examination of the properties of LBO crystals, the laser-damage thresholds of LBO crystals, and the laser-damage thresholds of thin films deposited on LBO crystals, with a summary of research achievements and recommendations on issues to be further investigated. Additionally, this paper discusses the promising prospects for the widespread application of LBO crystals.