Spectroscopy and lasing of a high Nd concentration Al-phosphate glass

An Al-phosphate glass containing Nd³⁺in concentrations ranging from to ions/cm³has been prepared and investigated spectroscopically. Different ways of measuring the⁴F3/2→⁴I9/2emission cross sections yield values between and cm². At the highest concentration the decay time is 50 μs, while the radiative lifetime is estimated to be s. Lasing experiments were performed by pumping thin platelets of glass coaxially with a dye laser. Cross sections, losses, and differential efficiencies are derived from these experiments. The status of high concentration glasses versus stoichiometric Nd compounds is reviewed.