A virtual source that generates a cylindrically symmetric Laguerre–Gauss wave of radial mode number n is introduced. An expression is derived for this Laguerre–Gauss wave that in the appropriate limit yields the corresponding Laguerre–Gauss beam. From the spectral representation of the Laguerre–Gauss wave, the first three orders of nonparaxial corrections for the paraxial Laguerre–Gauss beam are determined. On the beam axis, the number of orders of nonvanishing nonparaxial corrections is found to be equal to <i>n</i> .
© 2002 Optical Society of America
(010.3310) Atmospheric and oceanic optics : Laser beam transmission
(260.1960) Physical optics : Diffraction theory
(260.2110) Physical optics : Electromagnetic optics
(350.5500) Other areas of optics : Propagation
S. R. Seshadri, "Virtual source for a Laguerre-Gauss beam," Opt. Lett. 27, 1872-1874 (2002)