An intuitive model for on-axis pulse evolution of ultrashort pulsed Gaussian beams diffracted from a circular aperture

Abstract

The diffraction of ultrashort pulsed Gaussian beams from a circular aperture is studied by means of Fresnel diffraction integral and Fourier transform method. A uniform analytical expression is derived for temporal pulse form of ultrashort pulsed Gaussian beams in two cases, i.e. with constant beam waist and with constant diffraction length. It is shown that the on-axis pulse can be formulated as a superposition of an unapertured pulse and an aperture-induced pulse. The superposition of these two pulses leads to an enhanced pulse intensity for small truncation parameters at certain distances in the near field. Our results may find applications in high-intensity laser waveform control.

Keywords:

• ultrashort pulse
• diffraction
• hard aperture

Additional information

Funding

This work was supported by startup funding from University of Electronic Science and Technology of China [grant number 2013-QR-14]; the Chinese National 1000 Plan for Young Talents; and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China [grant number 61421002].