Lasing efficiency and photochemical stability of IR laser dyes in the 710-1080-nm spectral region

The lasing efficiencies and photochemical stabilities of laser dyes useful in the 710-1080-nm spectral region have been investigated using a
Q
-switched ruby laser pumping source. The measured bleaching rates
P
defined as the probability of irreversible decomposition of a dye molecule per absorbed photon, varied from
\leq 1 \times 10^{-5}
to
3 \times 10^{-4}
for the different dye-solvent combinations investigated. Broad-band lasing efficiencies (the ratios of dye laser output to ruby radiation input) ranged from 4 to 43 percent. Shifts of wavelength tuning range with variations in solvent, dye concentration, and dye laser cavity geometry are reported.