J. Phys. Colloques
Volume 48, Numéro C7, Décembre 19871st International Laser M2P Conference
|Page(s)||C7-447 - C7-450|
J. Phys. Colloques 48 (1987) C7-447-C7-450
LUMINESCENCE IN POTENTIAL FLUORIDE GLASS LASERSC.K. JØRGENSEN
Section de Chimie, Université de Genève, 30, Quai Ansermet, CH-1211 Genève 4, Switzerland
Fluoride glasses of the zirconium barium lanthanide type (invented Rennes, 1975) and lead gallium zinc (or manganese) type (invented Le Mans, 1979) show luminescence of lanthanide J-Levels situated at least 2000 cm-1 above the closest lower level (this limit is a few times larger in most other materials). Not only is the non-radiative de-excitation as weak as incrystalline LaF3 (studied by Weber) but energy transfer between neodymium and ytterbium (III), or from manganese (II), and to some extent from chromium (III), to luminescent J-levels of neodymium (III), erbium(III) and thulium (III) is highly efficient even at low concentrations. One advantage for laser applications is that the lowest quartet state of manganese (II) has a life-time 10 to 15 milliseconds (like in many phosphate glasses and crystalline compounds) allowing energy transfer, extending by huge factors the average life-time of the emitting J-levels. Though the terawatt lasers (Livermore, California, 1978) inducing deuterium-tritium fusion are silicate glass containing neodymium (III), fluoride glasses should be preferable for many purposes. The evaluation of laser parameters from small-scale experimentation is feasible.