Fluorescence in dual-wavelength pumped Ho3+-fluorozirconate fibers

The authors study holmium-doped fluorozirconate fiber pumped simultaneously by HeNe and a laser-doped diode contrapropagating through the fiber. The experiments are described. Dual-wavelength induced fluorescence bands were identified. The two pumping wavelengths were 630 and 830 nm, and strong enhancement of the fluorescence is observed in the 545- and 750-nm ranges. The fiber fluorescence efficiency is modeled with the use of perturbation theory describing the propagation of all the waves involved in the absorption-emission process. Experimental results and theory are qualitatively in agreement