Simultaneous oscillations of different transitions in lasers

Rate equations for multitransition lasers were investigated theoretically and the effect of fluorescence properties of multilevel lasers on laser performance was examined. Simultaneous oscillations of different transitions (MTO) were found to occur due to the difference in resonator loss for individual transitions. Conditions for single transition laser oscillations (STO) as well as oscillation states in MTO were obtained. Experiments were carried out using LiNdP
4
O
12
lasers and MTO was obtained in
⁴
F_{3/2}(1) \rightarrow
⁴
I_{11/2} (1, 2, 3)
transitions. Dependence of oscillation states on various laser parameters was given. The oscillation mode spectra and output waveform of MTO lasers were also presented.