EFFECT OF THE SWITCHING PATTERN OF THE ILLUMINATION OF DYNAMIC APERTURES ON THE RANGES OF THE GENERATED LOCALIZED WAVES

We study two different switching patterns of dynamic apertures illumin ated by a focus-wave-mode excitation field. The two sources are chosen to be identical except that one is illuminated with use of a Gaussian time window, whereas the other uses a periodic function defined over the same time span. In spite of the similarity between the two dynamic apertures, the decay patterns of the amplitudes of their radiated fie lds are significantly different. A detailed analysis of the depletion of their spectral contents shows that the coupling between the spatial and temporal spectral components plays a decisive role in extending t he range of the localization of the radiated pulses. (C) 1996 Optical Society of America.