Enhanced mid-infrared emission of Pr3+ ions in solids through a “3-for-1” excitation process – quantified
Abstract
Evidence is presented that a “three-for-one” process based on two cross-relaxations between Pr3+ ions efficiently populates the mid-infrared-emitting 3H5 manifold in a Pr3+-doped low-maximum-phonon-energy host. The concentration dependence of infrared fluorescence spectra and lifetimes of polycrystalline Pr:KPb2Cl5 initially excited to the 3F3,4 manifolds indicate that the 3500-5500-nm fluorescence becomes strongly favored over shorter-wavelength infrared emission bands in the higher-concentration sample. The strong concentration dependence of the 3F3 and 3H6 manifold lifetimes suggests that both of these decay by cross-relaxation processes, resulting in more than one ion excited to 3H5 for each ion initially excited to 3F3. Indeed, modeling and accounting for all possible decay paths indicate that, on average, about 2.3 ions are excited to 3H5 for each initially-excited ion. This confirms that the three-for-one excitation process must occur and contribute significantly to the total excitation efficiency. These results indicate that the two distinct cross-relaxation processes observed between Pr ions result in substantially higher excitation quantum efficiency, 230%, than any ever reported in rare-earth doped materials.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 08, 2021
- Source ID
- 10.1364/oe.441516
Entities
People
- E. Brown
- Jan L Allen
- Larry D. Merkle
- Mark Dubinskii
- Uwe Hömmerich
- Zackery Fleischman
Organizations
- Army Research Office
- Hampton University
- National Science Foundation
- Oak Ridge Associated Universities
- United States Army Research Laboratory