Fluorides

Doping of fluorides with trivalent rare earth ions requires charge compensation which complicates the crystal growth process. The important representative of this crystal family is yttrium fluoride (YLiF₄), a uniaxial crystal. YLiF₄ is transparent to 150 nm. Therefore, high-current-density xenon flashlamps which emit strongly in the blue and near-ultraviolet can be used as pump sources without damage to the material. The most common dopant of YLF is Nd³⁺. Nd:YLF offers a reduction in thermal lensing and birefringence combined with improved energy storage relative to Nd :YAG. The thermomechanical properties of Nd : YLF, however, are not as good as those of Nd :YAG. Details of Nd : YLF.