Spectroscopy and lasing in K5NdLi2F10 /KNLF

A new stoichiometric compound of Nd, K5NdLi2F10 has been synthesized and its spectroscopic and lasing properties are reported. The material is characterized by a room temperature decay time of 300 microsec, increasing to 500 microsec in diluted samples. This represents the least amount of concentration quenching reported in this class of compounds. The spectroscopically determined peak emission cross section for the 1048 nm lasing line is 12 x 10 to the -20th power sq cm, about twice the value obtained from laser experiments. A calculated radiative lifetime agrees with observed decay time for samples with less than 10 percent Nd content, indicating a quantum efficiency near unity. The concentration quenching in this material is discussed and found to be considerably lower than predicted from spectroscopically obtained rates of pair cross relaxation.