The emission of Nd:YLF to unpopulated terminal levels includes prominent lines at 1.047, 1.053, 1.313, 1.321 microns and continuous emission over the band between 1.362 to 1.374 microns. The properties of this system permit Q-switched operation on all these lines in spite of very high gain competition from the strongest (1.047) peak. Several schemes for shifting these lines to the Cs resonance lines are described.
M. G. Knights,
"Cesium Filter Resonant Operation Of Nd:Ylf", Proc. SPIE 0622, High Power and Solid State Lasers, (23 June 1986); doi: 10.1117/12.961184; https://doi.org/10.1117/12.961184