OPTICAL-PROPERTIES AND ENERGY-TRANSFER AMONG ND3-CA2AL2SIO7 CRYSTALS FOR DIODE-PUMPED LASERS( IN ND)

The energy levels of neodymium in the Nd3+:Ca2Al2SiO7 (CAS) laser mate rial with gehlenite structure are reported. As the Nd3+:Ca2Al2SiO7 com pound presents a broad absorption around 806 nm, it is a good candidat e for diode pumped laser. The F-4(3/2)-->I-4(9/2) and F-4(3/2)-->I-4(1 1/2) emission have been recorded and the fluorescence branching ratios calculated from the Judd-Ofelt analysis are 0.41 and 0.47 respectivel y. The emission cross section at 1.06 mu m (F-4(3/2)-->I-4(11/2) trans ition) is 5 X 10(-20) cm(2). The decay profiles of the Nd3+ emission h ave been analyzed for several Nd3+ concentrations using the kinetic mi croparameters related to the cross relaxation (C-DA = 1.7 X 10(-40) cm (6) s(-1) and R(0) approximate to 6 Angstrom) and the energy migration probabilities (C-DD=20 X 10(-40) cm(6)s(-1)). In the Nd:CAS laser mat erial, the optimal concentration corresponding to the maximum of the f luorescence intensity is determined to be around 2.7 X 10(20) Nd3+ ion s cm(-3). The Nd3+-Nd3+ interactions are not very strong in this mater ial as the optical concentration value is two times higher than in the Nd:YAG laser material.