The optical response of single-crystal Nd:YAG and Cr<sup>3+</sup>:YAG to ionizing radiation has been previously studied
using intense pulses of gamma-rays at the HERMES III facility at Sandia National Laboratory, where samples'
transmission at 1064 nm was observed during exposure to gamma radiation. A further study of similar samples
when exposed to 10-ns UV laser pulses reveals nearly identical dynamics, with both tests producing similar transient
and permanent response in the medium. This strongly suggests that the material response to UV radiation can be
used to gauge its gamma-radiation hardness, therefore yielding a material testing technique that is much simpler and
less costly than gamma-radiation tests.
Increased reliance on optical components in harsh radiation environments requires a deeper understanding of the
radiation-induced behavior of common optical elements. Of particular interest is the impact of ionizing radiation on both
optical transmission and absorption. The present work focuses on an examination of the optical response of singlecrystal
Nd:YAG, Cr:YAG and co-doped Nd:Cr:YAG to pulses of gamma-radiation. In-situ, transient optical behavior was observed by measuring the transmittance of the materials at 1064 nm before, during and after exposure to 30-60 krad (Si) of pulsed gamma radiation. The
gamma-radiation-induced response of the Cr-doped materials was seen to exhibit exceptional radiation resistance as compared to the undoped YAG and to the Nd-doped materials. Furthermore, the addition of Cr<sup>3+</sup> into the Nd:YAG crystal matrix was seen to greatly improve the radiation resistance of the laser materials. Both transient and permanent effects will be discussed.