Short pulse propagation in tight focusing conditions

Abstract We report short pulse propagation simulation data generated by 3 D +1 (x,y,z,t) code which takes into account space–time Laplacian, up to cubic term dispersion, delayed Kerr non-linearity, optical shock term and multi-photon ionization. The input phase front of the pulse is taken to be parabolic corresponding to focusing/defocusing conditions, while the intensity spatial distribution is Gaussian. The temporal pulse shape is taken to be either sech 2 ( t ) or Gaussian type with encoded chirp phase information. We discuss various implications of tightly focused beam on bulk laser ablation (micro-machining) and super continuum (SC) generation. These include blue spectral enhancement of SC with pulse breaking into shorter pulses and detrimental effect of very short pulses on micro-machining.

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