Possibility of obtaining efficient cw stimulated emission from optically pumped lasers utilizing self-terminating transitions

The possibility of obtaining cw stimulated emission from lasers utilizing self-terminating transitions (for example, Cu and Mn vapor lasers) under conditions of optical pumping of the resonance levels of the active element is demonstrated theoretically. It is shown that optical pumping permits the familiar methods of depopulating the metastable levels of the active gas to be utilized more efficiently. The pumping efficiency of this laser system is close to the quantum efficiency and may reach several tens of percent. It is shown that a gain higher than ~10^–3 cm^–1 and a laser radiation output power of the order of 100 W/m of the active medium may be achieved in these laser systems at a pump power density of ~0.3 W/cm².