Multistability and periodic alternance in a multimode CO2 laser with a saturable absorber

D. Wilkowski, D. Hennequin, d. Dangoisse, P. Glorieux

Chaos Solitons Fractals 4 1683-1698 (1994)

The transverse dynamics of a multimode CO2 laser with SF6 as an intracavity saturable absorber is experimentally studied. Generalized multistability, periodic alternance and passive Q-switching involving several laser transverse modes have been observed. The dynamics is more particularly studied in the simplest case of the bimode laser where antiphase and in-phase self-oscillations are obtained. In the highly multimode case, experimental conditions are found in which the absorber acts as a mode filter that reduces complex transverse patterns to almost pure Hermite-Gauss modes.