4T2→4A2 transition in the luminescence spectra of Mn4+ ion in gadolinium gallium garnet at intense laser pumping

The Mn4+ T-4(2) --> (4)A(2) transition was observed in the luminescence spectrum of Gd3Ga5O12:Mn4+ at intense laser pumping. It is shown that the T-4(2) --> (4)A(2) transition becomes more intense than E-2 --> (4)A(2) because of an increase in the role of induced transitions with increasing pump power. This process is most efficient in the region of strongest overlap between the E-2 --> (4)A(2) and T-4(2) --> (4)A(2) bands, where it leads to strengthening of the zero-phonon line of the latter at 694 nm. It is assumed that GGG:Mn4+ can be used as an active material in tunable lasers. (C) 2001 MAIK "Nauka/Interperiodica".