POPULATION KINETICS IN ERBIUM DOPED LASER CRYSTALS PRODUCED BY EXCITATION WITH AN Er : GLASS LASER AT 1.53 MICRONS M. BIRNBAUM, K. SPARIOSU et B. VIANAJ. Phys. IV France, 01 C7 (1991) C7-422DOI: https://doi.org/10.1051/jp4:19917110