Spectroscopic characterization of Tm:CaYAlO4 shaped crystal fibers grown by the micro-pulling-down method.

Tm3+-doped CaYAlO 4 (Tm:CALYO) shaped crystals fibers with various doping concentration of 2 at.%, 3 at.%, 5 at.% and 7 at.% have been successfully grown by the micro-pulling-down (μ -PD) method. The polarized absorption spectra, polarized fluorescence spectra and fluorescence decay curves were analyzed at room temperature. The absorption bands of 3H 6 →3H 4 transition centered at around 800 nm match well with commercial AlGaAs laser diode pumping sources. For 7 at.% Tm:CALYO crystal fiber, the full width at half maximum (FWHM) of the emission band for π polarization at 1806 nm was 225.4 nm. The fluorescence of 3F 4 level decreased strongly as the thulium concentration increased. All the results indicate that Tm:CALYO crystal fibers are promising for ultrashort and tunable laser operation. • Tm:CALYO shaped crystal fibers were grown by the micro-pulling-down technique for the first time. • The full width at half maximum (FWHM) of the emission band for π polarization at 1806 nm was calculated to be 225.4 nm. • The fluorescence lifetime was calculated to be 4.11, 3.74, 3.55 and 2.90 ms for doping concentration of 2, 3, 5 and 7 at.%, respectively. [ABSTRACT FROM AUTHOR]