title: Virtual source for the Bessel-Gauss beam.
abstract: The virtual source for generation of the fundamental scalar Bessel-Gauss wave is identified. An expression is derived for the Bessel-Gauss wave, which, in the appropriate limit, yields the paraxial approximation for the fundamental Bessel-Gauss beam. For the azimuthally symmetric beam, the first-order nonparaxial correction to the on-axis field is also determined. This nonparaxial correction reduces correctly to that of the fundamental Gaussian beam in the appropriate limit.
authors.forename: S R
authors.initials: SR
authors.lastname: Seshadri