TIME-RESOLVED SPECTROSCOPY OF LASER OUTPUT OF ND3+ DOPED CALCIUM, NIOBIUM, GALLIUM GARNET

Stimulated emission experiments in the F-4(3/2) --> I-4(11/2) transiti on of Nd3+ in Ca-3(GaNb)(2)Ga3O12 show that two laser lines are emitte d simultaneously and both independently. These experiments show the be haviour of the laser emission from two distinguishable subsets of Nd3 sites. This behaviour has been modeled using a four-level spectral ra te-equation laser model, assuming the existence of two kinds of Nd3+ p opulations with different emission spectra and a homogeneous line broa dening at each site. The model explains the measured laser spectrum as well as the time delay between the emission of both laser lines.