Chen, J.-C.J.-C.ChenLo, C.-Y.C.-Y.LoHuang, K.-Y.K.-Y.HuangKao, F.-J.F.-J.KaoTu, S.-Y.S.-Y.TuSHENG-LUNG HUANG2018-09-102018-09-10200500220248http://www.scopus.com/inward/record.url?eid=2-s2.0-12244262292&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/316303https://www.scopus.com/inward/record.uri?eid=2-s2.0-12244262292&doi=10.1016%2fj.jcrysgro.2004.10.063&partnerID=40&md5=ef804c2cb96b712a903f9108bd72faccWe 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.Chromium; Doping (additives); Fibers; Fluorescence; Ions; Optical microscopy; Refractive index; Stress analysis; Charge compensation; Core diameters; Laser heated pedestal growth; Stress-induced striations; Crystalsjournal article10.1016/j.jcrysgro.2004.10.063