Concentration and power dependences of level population of 2.8 - μm laser transition in YLF : Er crystals under CW laser diode pumping

摘要

An influence of interionic cross relaxation processes (upconversion, selfquenching) on concentration and power dependences of the inverse population of~4I_(11/2) and~4I_(13/2) laser levels in YLF:Er crystals under CW laser-diode pumping were studied both theoretically and experimentally. Computer simulations were carried out taking into account not only-pair interaction but also the multi-ion interaction in the whole system. Optimal Er concentration for 3 -μm CW lasing was estimated as 10 - 15%.