Stimulated emission in the system CO/CO2

Yu.V. Volk, Alexander M. Malyarevich, Konstantin V. Yumashev +4 more

This paper investigates the differential absorption spectra of a number of transparent spinel-based cobalt-containing aluminosilicate glass-ceramics in the 550-700-nm range. A stimulated emission band accompanying transitions between the 4T1(4P) and 4A2 levels of the tetracoordinated Co2+ ion is detected in all the materials. Depending on the composition of the glass-ceramic, the effective stimulated-emission cross sections of the Co2+ ions at the maximum of this band are estimated at (4-5)×10−19 cm2.

H.-G. Unger

Sergei G. Pavlov, Heinz‐Wilhelm Hübers, Mark Hermann Rümmeli +4 more

Far-infrared stimulated emission from optically pumped neutral Bi donors in silicon has been obtained. Lasing with wavelengths of 52.2 and 48.6 μm from the intra-center 2p±→1s(E:Γ8),1s(T2:Γ8) transitions has been realized under CO2 laser pumping. The population inversion mechanism is based on fast optical-phonon-assisted relaxation from the 2p0 and 2s excited states directly to the ground 1s(A) state leading to relatively small population in the intermediate 1s(E), 1s(T2) excited states.

Mathieu Hautefeuille, Juan A. Hernández-Cordero

Robert P. Davis

Andreas Dreuw, Lorenz S. Cederbaum

Motivated by the experimental observation of a long-lived CO 2 - state, we have investigated several sextet states of this species. In analogy to recent results for long-lived sextet states of CO - , we focus on long-range minima of the sextet ground state 6 A 1 of CO 2 - . We have found two minimum geometries at very long internuclear distances, which can be explained as loosely bound complexes between a C - ion and an oxygen molecule in their respective ground states. Both long-range isomers of the 6 A 1 state are stable with respect to single-electron emission and dissociation. Since all other decay channels are spin forbidden, these species are long lived.