Wavelength dependent refractive effects and Stark broadening in laser-induced YBa2Cu3Ox plasma plumes

Spectral lines observed at short delay times and close to the target during laser ablation of YBa2Cu3Ox show strongly distorted line shapes arising partly from optical refraction by the large density gradients within the expanding plume. Spatially and temporally resolved linewidths, corrected for refraction effects, are reported for the Ba(I) 553.5 nm absorption transition and Stark widths, deduced from these corrected linewidths, indicate that the maximum electron number density at 1.0 mm from target is similar to 1 x 10(19) cm(-3). (C) 1996 American Institute of Physics.