A Kar

Heriot-Watt University, Edinburgh, SCT, United Kingdom

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Publications (1)3.55 Total impact

  • K Cook, A Kar, R A Lamb
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    ABSTRACT: The effect of beam spatial profile on self-focusing has been investigated. A circular aperture is used to create a Fresnel diffraction pattern. It is shown that self-focusing (a pre-requisite for filament formation) occurs in the presence of the aperture but that no formation is observed when the aperture is removed, even though the beam has higher power well above the threshold for critical power. An analytical solution to the Huygens-Fresnel diffraction integral shows that the axial intensity oscillates between maxima and minima as the distance from the aperture increases and that filament formation coincides with the presence of an axial maximum.
    Optics Express 04/2005; 13(6):2025-31. · 3.55 Impact Factor

Publication Stats

9 Citations
3.55 Total Impact Points

Top Journals


  • 2005
    • Heriot-Watt University
      • Department of Physics
      Edinburgh, SCT, United Kingdom