Abstract

Sparks in the form of long, thin filaments having quasi-periodic longitudinal light and dark regions (striations) in time-integrated images have been observed in various gases using a CO₂ TEA laser. Typically, a 50-mJ pulse will produce a filament 1 cm long and 130 μm in diameter, with more than 150 striations spaced 50 μm apart in atmospheric air. Each striation is associated with the formation of a plasma region by one pulse in a train of pulses from the mode-locked laser, and the filament results from the formation of successive (nearly identical) regions, each displaced from the previous one toward the laser. The possible use of these sparks as a light source in diagnostics is noted.

© 1979 Optical Society of America

Recombination lasers in Nd and CO₂ laser-produced cadmium plasmas

W. T. Silfvast, L. H. Szeto, and O. R. Wood
Opt. Lett. 4(9) 271-273 (1979)

Injection mode locking of a TEA CO₂ laser on P and R transitions in the 9- and 10-μm bands

P. E. Dyer and I. K. Perera
Opt. Lett. 4(8) 250-252 (1979)

Stable pulses of variable width from a mode-locked hybrid TEA-CO₂ laser

P. Bernard and P. A. Bélanger
Opt. Lett. 4(7) 196-198 (1979)

Selective-absorption cross section of CF₃CHCl₂ and CF₃CDCl₂ at 10.2 and 10.6 μm of a TEA CO₂ laser

S. L. Chin and G. Boisclair
Opt. Lett. 4(10) 340-341 (1979)

Switching of a TEA CO₂ laser with its own UV emitting parallel spark channels

J. Padma Nilaya, Pallavi Raote, Gautam Patil, and Dhruba J. Biswas
Opt. Express 15(1) 129-136 (2007)