Optical properties of Ba-In-Ga-based fluoride glasses for amplification at 1.3 um

Optical properties of rare-earth ions in glasses based on barium, indium, gallium, zinc, yttrium/lutetium, and thorium fluorides are presented. Multiphonon relaxations are determined and are found to be significantly lower than in ZBLAN fluoride glasses. Also, spectroscopic properties of the 1.3?m emission of neodymium (III) and praseodymium (III) ions in fluoride glasses are studied. Excited state absorption from the 4F3/2 emitting level of neodymium (III) as well as radiative and non-radiative properties of the 1G4 level of praseodymium (III) are compared in Ba-In-Ga and ZBLAN glasses.