Filamentation of a Sharply Focused Ultrashort Laser Pulse at Wavelengths of 800 and 400 nm: Measurements of the Nonlinear Index of Air Refraction

摘要

We present the results of experimental investigations of the filamentation dynamics of highpower ultrashort Ti:Sapphirelaser pulses with wavelengths of 800 and 400 nm with their sharp focusing in air. The dependences of position and dimensions of a plasma channel generated in the nonlinear beam focus zone on the laser pulse power are obtained. The effective value of the nonlinear index of air refraction related to the optical Kerr effect is determined for two laser wavelengths from processing of the dependences when using laser radiation selffocusing theory.