COMPARISON OF THE PROPAGATION CHARACTERISTICS OF BESSEL, BESSEL-GAUSS, AND GAUSSIAN BEAMS DIFFRACTED BY A CIRCULAR APERTURE

We use the scalar Kirchhoff-Huygens diffraction integral to obtain analytic expressions for both axial and transverse intensity distributions, assuming normal incidence on a circular aperture for four types of incident field: (1) plane wave, (2) Bessel beam, (3) Gaussian beam, and (4) Bessel-Gauss beam. We use the Fresnel approximation to obtain the axial intensity as a function of distance from the aperture. We consider both Fresnel and Fraunhofer diffraction for the case of the transverse intensity distributions. For the axial case, we find that the Bessel-Gauss beam performs worse than the Bessel beam, in terms both of the magnitude of intensity and of its ability to extend a distance from the aperture. In the transverse case, we find that the Bessel-Gauss beam performance in terms of remaining nearly diffraction free over a given distance is highly dependent on the relationship among the aperture radius, the beam waist parameter, and the transverse wave number.