ABSTRACT
By means of a time-resolved, shadowgraphic method we observed directly the development of the pulse-splitting dynamics of a femtosecond laser pulse propagating in the filamentary regime in water. For the first time to our knowledge, the relative splitting velocity was measured. We compare the experimental data with numerical simulations. A possible scenario for the splitting event and evolution of the fragments is discussed.
ABSTRACT
By means of a quantitative shadowgraphic method, we performed a space-time characterization of the refractive index variation and transient absorption induced by a light-plasma filament generated by a 120 fs laser pulse in water. The formation and evolution of the plasma channel in the proximity of the nonlinear focus were observed with a 23 fs time resolution.
Subject(s)
Nephelometry and Turbidimetry/instrumentation , Photometry/instrumentation , Refractometry/instrumentation , Water/chemistry , Equipment Design , Equipment Failure Analysis , Hot Temperature , Light , Nephelometry and Turbidimetry/methods , Photometry/methods , Refractometry/methodsABSTRACT
Experiments show that the spatiotemporal spectral broadening of an intense pump pulse in a Kerr medium in the presence of strong higher-order dispersion does not lead to symmetric profiles, and hence cannot be interpreted as standard modulational instability of a plane and monochromatic nonlinear eigenmode. The highly asymmetric features of the generated (K perpendicular,Omega) spectrum are due to odd-order dispersion terms and are interpreted in terms of spontaneous formation of stationary conical waves.