For years, neodymium-doped yttrium aluminum Garnet (Nd:YAG) crystals of dopant levels of up to 1.1% concentration have been produced for military, industrial, medical, and scientific applications. More and more however, a need exists for crystals doped with higher neodymium concentrations. Nd:YAG crystals with dopant levels of 1.3% and 1.4% can produce greater efficiency in Q-switch operations, thus smaller crystals can be used to achieve the desired output power. Additionally, smaller crystals are easier to cool and therefore deleterious thermal effects can be minimized. It is difficult to incorporate the large diameter Nd3+ ion into the relatively small Y3+ sites of the YAG crystal lattice, which limits the achievable dopant concentration. In this paper, we will present the growth of highly doped Nd:YAG crystals with excellent optical quality achieved by modifying the growth parameters. Spectroscopy results and laser results obtained from our 1.3% and 1.4% Nd:YAG crystals will also be presented. (C) 2004 Published by Elsevier B.V.
