Measurements of spatial, temporal, and spectral dynamics of an ultra-short pulse in air

Summary form only given. We present experimental measurements that map out the structure of a self-focusing 800 nm ultrashort pulse propagating in air. We measure self-focusing with measurements taken over a maximum propagation distance of about 24 m that include shot-to-shot recordings of the pulse-energy, beam-profile images, autocorrelation data, and spectra. The data are taken at three propagation distances, 5.3 m, 11.3 m, and 24.3 m. At each of these positions along the beam path, the pulse energy is varied from about 0.2 mJ to about 3.5 mJ. By varying the energy in the laser pulse, and recording data for each pulse, a high-resolution mapping of the pulse evolution in the spatial, temporal, and spectral domains, is obtained as a function of pulse energy. The data is of sufficient precision for benchmarking self-focusing theory calculations, including the prediction of the nonlinear index, n/sub 2/, as well as dispersion in air.