Collapse dynamics of super-Gaussian Beams

Taylor D Grow,Amiel A Ishaaya,Alexander L Gaeta,Gadi Fibich,Nir Gavish,Luat T Vuong

doi:10.1364/oe.14.005468

Abstract

We investigate the self-focusing dynamics of super-Gaussian optical beams in a Kerr medium. We find that up to several times the critical power for self-focusing, super-Gaussian beams evolve towards a Townes profile. At higher powers the super-Gaussian beams form rings which break into filaments as a result of noise. Our results are consistent with the observed self-focusing dynamics of femtosecond laser pulses in air [1] in which filaments are formed along a ring about the axis of the initial beam where the initial beam did not form a ring.

Highlights

We experimentally examine the collapse dynamics of uniform-phase SG beams in which the ring profile is not present on the initial beam but is formed as the beam undergoes nonlinear propagation towards collapse
After the initial ring formation, the beams will continue to collapse and Fibich et al [13] have shown that the collapse rate for SG beams is different than that for Gaussian beams, which collapse to the Townes profile (TP), and that the profile evolves to a ring-shaped self-similar profile called the Gprofile [13]
In order to observe the dynamics of the pulse as it propagates through different lengths of the medium, the water cell is adjustable in length [26]

Summary

Introduction

“Self-similar optical wave collapse: observation of the Townes profile,” Phys. Recent theoretical work [13] has shown that super-Gaussian (SG) beams of sufficiently high power collapse towards a self-similar ring-shaped profile called the G-profile.

Results

Conclusion