Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
Efficient Pr3+ laser material excitation by three-for-one cross-relaxation
Larry D. Merkle, Mark A. DUBINSKII
Abstract
Pr3+ has three excited manifolds with the right energy spacings for emission between 3.5 and 5.5 microns, and can be excited efficiently using laser diodes developed for telecommunications. In the potential laser crystal Pr:RbPb2Cl5, we have observed strikingly strong fluorescence in this wavelength range following 1.53-micron excitation. Careful analysis indicates this must be due to two cross-relaxation processes that, together, efficiently convert one Pr3+ initially excited to the 3F3 manifold into three ions excited to the 3H5 manifold. This newly discovered “three-for-one” crossrelaxation process in Pr3+ may greatly enhance its utility as a mid-infrared laser ion.