Experimental study on small-scale self-focusing of femtosecond pulse with cross silk spatial diffraction modulation

摘要

We experimentally and theoretically investigate the propagation of intense femtosecond pulse in a nonlinear medium, in which the dynamic process of small-scale self-focusing of intense femtosecond pulse is experimentally investigated. By using tabletop femtosecond laser, the pulse which is spatially modulated by the cross silk diffraction passes through the nonlinear medium (carbon bisulfide, CS2). As the input power increases, the small-scale self-focusing of the pulse is obtained. By analyzing the contrast gradient of the beam, we can obtain the dynamic process of small-scale self-focusing. Finally, we find that the numerical simulations are in good agreement with experimental results.