We report experimental observations of temporal pulse-shape distortion in 1.7 ns 10.6-μm laser pulses passing through the multiphoton saturable absorber SF6 and an SF6-based fluorocarbon mixture. The observed effects include a lengthened risetime, delays in peak onset times, and a decrease in the pulse falltime which tends to symmetrize an input triangular pulse. The pulse-shaping effects are seen over a wide range of wavelengths, fluences and gas pressures. Qualitatively similar effects are predicted by a two-level saturable absorber model in an appropriate parameter space.
R. F. Haglund, R. F. Haglund,
"Temporal Shaping Of Nanosecond CO2 Laser Pulses In Multiphoton Saturable Absorbers", Proc. SPIE 0288, Los Alamos Conf on Optics '81, (30 December 1981); doi: 10.1117/12.932041; https://doi.org/10.1117/12.932041