四硼酸铝钕晶体及其小型全固态激光器

NEODYMIUM ALUMIUM TETRABORATE CRYSTAL AND MINIATURE ALL SOLID STATE LASERS

当前,全固态激光器在向万瓦级大功率方向发展的同时,也在向微型化发展。利用碟片全固态激光器可获得千瓦级以上激光,利用微片全固态激光器则可实现小体积、高密度、中小功率激光输出。获得高功率高密度激光的关键在于激光材料。本文从碟片和微片激光器的发展和对激光基质材料的要求出发,概述自激活激光晶体的研究,特别对四硼酸铝钕[NdAl3(BO3)4,简称NAB]晶体的结构、生长、性质及其作为有应用前景的小型片状激光器的候选材料作了详细的介绍。近期,采用面积为4×4 mm2,厚度为0.39 mm的微片NAB晶体,用885 nm半导体激光器为光源泵浦,获得了4.6 W的1.063μm激光的有效输出,其斜效率达到64%,充分显示了NAB晶体作为自激活激光晶体在微片激光器中的应用前景。

The development of all solid state lasers towards the high power and miniature products have been receiving general interests. The disk-type all solid state lasers can offer laser beams of kW in power, while the microchip lasers are favored because of their small volume and high efficiency/high density for medium/low power output. It is well known that high quality laser crystals are the pre- requisites for fabricating high performance lasers. In this article, we summarize the state-of-art of self- activatea laser crystals including detailed description of their structures, properties, and performances, based on the requirements for miniature laser applications. Particular attentions are paid to neodymium aluminum tetraborate （NdAl3 （BO3）4, one of the typical and also best self-activated laser crystals. We highlight the main results of investigation on the structure, growth process, and performances of NdAl3 （BO3）4, as well as its potential applications in miniature lasers. Recently, a 1. 064 μm laser beam output of 4.6 W in power and 64% in slop efficiency, using a 4× 4 × 0.39 mm3 NdAl3 （BO3）4 disk crystal pumped with a 883 nm LD laser, has been reported, demonstrating the promising potential of NdAl3 （BO3）4 as self-activated laser crystal in miniature lasers.