Abstract

We have investigated multiphoton fragmentation processes in CO₂ as a function of pressure (10⁻⁴−100 Torr) and excitation wavelength. Subsequent to excitation by a line-narrowed (~3-cm⁻¹) tunable (~150-cm⁻¹) ArF* excimer laser (λ ~ 193 nm), we monitored the dispersed fluorescence along with the ion signal produced by the photofragments. Although CO₂ has no strong intermediate resonances at 193 nm, our preliminary results show a strong three-photon photolysis channel leading to atomic carbon which suggests a complete breakup of the molecule. At the same time, CO₂ sustains laser-induced breakdown at relatively low pressures (~7 Torr), which indicates a strong multiphoton (at least three) ionization channel as well.

© 1987 Optical Society of America