Emission Regimes of a Green Er:${\hbox {YLiF}}_{4}$ Laser

We present an analysis of the emission regimes of an Er:YLiF
₄
laser on the transition
⁴
S
_3/2
rarr
⁴
I
_15/2
, under direct pumping and various upconversion pumping mechanisms. The analysis is based on the study of the steady-state solutions of a rate equation system. The thresholds of the various emission regimes are calculated. The influence of the pump mechanism and the excited-state absorption losses on the emission regime is discussed.