Investigation of the relation between the radiation energy of a laser with passive mode locking and the spectral-luminescent characteristics of saturating absorbers

Criteria for the choice of saturating absorbers for passive mode locking in a YAG:Nd(3+) laser are determined on the basis of an investigation of the relation between the spectral characteristics of the saturating absorbers and the magnitude of the laser energy output. The recently synthesized analog of the dye No. 3955 with anions BF4, ClO4, F3CSO3, and the widely used dyes No. 3955 and No. 3274y are studied. Luminescence spectra of the compounds are measured in several solvents during quantum excitation of various energy levels, spectra, and absorption profiles in the maximum and on the lasing wavelength. Measurements of the energetic and temporal characteristics of lasing are presented. It is shown that, in the selection of a saturable absorber, dye solutions should be used that have the highest values of section magnitudes in the maximum of the absorption spectra and the generation frequency, a slight Stokes shift and the frequency of a pure electron transition, which coincides with the generation frequency.