Fluorescence mapping of oxidation states of Cr ions in YAG crystal fibers
Journal
Journal of Crystal Growth
Journal Volume
274
Journal Issue
44624
Pages
522-529
Date Issued
2005
Author(s)
Abstract
We have demonstrated the use of laser scanning confocal microscope for mapping the refractive index as well as Cr3+ and Cr4+ fluorescence in Cr:YAG crystal fibers with 1 μm spatial resolution. The corresponding sensitivities for Cr3+ and Cr4+ fluorescence intensities are 1.6×1017/cm3 and 7.5×1015/cm3, respectively. The share of Cr 4+ ions in the total Cr concentration is found to be proportional to the ratio of Ca to Cr concentrations. However, only less than 1% of the Ca 2+ ions become active in charge compensation. The concentration of Cr4+ ions is higher near the center of the crystal fiber when the core diameter is less than 300 μm. In addition, stress-induced striations created near the fiber center disappear when the fiber diameter is smaller than 500 μm. © 2004 Elsevier B.V. All rights reserved.
Other Subjects
Chromium; Doping (additives); Fibers; Fluorescence; Ions; Optical microscopy; Refractive index; Stress analysis; Charge compensation; Core diameters; Laser heated pedestal growth; Stress-induced striations; Crystals
Type
journal article