This paper presents the elements of the theory and the results of an analysis of the spatial distribution of the field characteristics in the neighborhood of the focus for an input pulse in the form of a harmonic vibration with a Gaussian envelope. The signal parameters are varied from an ultrashort to a quasi-monochromatic pulse. The evolution in time of the input pulse and the edge wave is demonstrated. It is shown that the field structure in the focal plane approaches that for a monochromatic wave when the effective number of vibrations is greater than 3–5.
© 2012 OSA
Original Manuscript: April 7, 2011
Published: February 29, 2012
M. V. Lukashova and Yu. A. Tolmachev, "Field structure of a spherical wave in the neighborhood of the focus," J. Opt. Technol. 79, 70-74 (2012)