Irregular and nonrepetitive transverse intensity distributions were measured in the near field during the gain-switch pulse (60-ns width) of a transversely excited atmospheric CO2 laser. Transverse patterns are regular and repetitive in the long-pulse (1-μs width) mode and in ensemble average in the short-pulse mode, and in both cases symmetry is imposed by the boundary conditions. Short-pulse transverse patterns formed by lasing domains appear with a mean size of 0.8 mm. The prediction of domain size based on a model of population inversion filamentation agrees with the experimental result.
© 1996 Optical Society of America
Original Manuscript: January 23, 1996
Published: August 1, 1996
F. Encinas-Sanz, I. Pastor, and J. M. Guerra, "Transverse pattern morphogenesis in a CO2 laser," Opt. Lett. 21, 1153-1155 (1996)