Electronic Bottleneck and Coherent Vibrational Effect on Relaxation Dynamics of Photoexcited Ions in Crystals
Abstract
Nonradiative relaxation processes of photoexcited impurity ions in Cr(sup 4+) -doped forsterite (Cr(sup 4+)::Mg2SiO4) and Cunyit (Cr(sup 4+): Ca2GeO4) laser crystals have been investigated using time-resolved resonance Raman and up-converted hot luminescence spectroscopy methods. The nonequilibrium population of a local mode of 765 cm(sup -1) in Cr(sup 4+):Mg2SiO4 was found to build up during the transition through an electronic bottleneck and decay by interaction with a restricted number of phonon modes. The resonance energy transfer from a local mode of 733 cm(sup -1) in Cr( sup 4+): Ca2GeO4 to resonance phonon mode of the host crystal was found to dominate the initial step of the energy relaxation of the photoexcited impurity ions. Our work has gained a better understanding of the electronic-vibronic nonradiative relaxation processes which is of great importance for optical and lasting properties of solid state tunable crystals.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2000
- Accession Number
- ADA389507
Entities
People
- C. H. Liu
- Robert Alfano
- S. Owen
- W. B. Wang
Organizations
- City College of New York