Fluorescence mapping of oxidation states of Cr ions in YAG crystal fibers

Study of Spectroscopy and Microstructure in Nanocrystalline Cr-Doped Fibers Grown by the Drawing-Tower Technique

“…The lifetime of the CDF grown by the drawing-tower method was around 1.86 ls with a 850-nm pumping source, which was shorter than the 3.28 ls in the core of a CDF grown by the LHPG method. 7,8 Figure 3 shows the proportional profile of CDF compositions as measured by an electron probe microanalyzer (EPMA; JXA-8900R, JEOL). As can be seen, there was interdiffusion between the Cr 4+ :YAG crystal and SiO 2 (cladding).…”

“…A Cr 4+ :YAG crystal fiber has recently been fabricated using a co-drawing laserheated pedestal growth (LHPG) method 7,8 or a drawing-tower technique. 9,10 Cr-doped fibers (CDFs) have demonstrated broadband emissions over the entire 1.3 lm to 1.6 lm range.…”

Simulation and experiment on laser-heated pedestal growth of chromium-doped yttrium aluminum garnet single-crystal fiber

“…Fig. 2(a) shows a comparison between the Cr 3 + fluorescent intensity profile, measured by laser scanning confocal microscopy (LSCM) [25] and the concentration of chromium (III) oxide (Cr 2 O 3 ), measured using an electron probe micro-analyzer (EPMA) for calibration. LSCM permits measurement of the characteristic spectrum of Cr 3+ ion using a confocal microscope with a 532-nm frequency-doubled Nd:YVO 4 laser acting as light source for pumping the Cr 3 + ions to scan the fluorescent intensity profile across the fiber cross section.…”

On the deposition of Cr3−O4 spinel particles upon laser-heated pedestal growth of Cr:YAG fiber

“…A multi-wavelength confocal fluorescent microscope was used to reveal a higher Cr 4+ fluorescence intensity for the core of the as-grown crystal fiber [29]. The fluorescence intensity was further found to decrease and shift to lower wavelength for the silicate inner cladding in comparison with the core [11].…”