Spectroscopy of Ce-codoped Er:BaY2F8 single-crystals

To study the fruitful effect of Ce codoping in Er:BaY2F8 for laser operation at around 1.5 μm, we present the spectroscopic characterization of several Er–Ce codoped crystals as a function of Ce doping level. We show that the Ce presence triggers some cross-relaxation mechanisms from energy levels higher than 4I13/2 that strongly help the population inversion efficiency for the 1.5 μm emission, without greatly affecting the 4I13/2 level lifetime. This result may be interesting from the point of view of obtaining a low-threshold infrared laser.