Based on the perturbative series representation of a complex-source-point spherical wave an expression for cylindrically symmetrical complex-argument Laguerre–Gauss beams of radial order n is derived. This description acquires the accuracy up to any order of diffraction angle, and its first three corrected terms are in accordance with those given by Seshadri [Opt. Lett. 27, 1872 (2002)] based on the virtual source method. Numerical results show that on the beam axis the number of orders of nonvanishing nonparaxial corrections is equal to n. Meanwhile a higher radial mode number n leads to a smaller convergent domain of radius.
© 2008 Optical Society of America
Original Manuscript: January 3, 2008
Revised Manuscript: March 27, 2008
Manuscript Accepted: March 28, 2008
Published: May 9, 2008
Shaohui Yan and Baoli Yao, "Exact description of a cylindrically symmetrical complex-argument Laguerre-Gauss beam," Opt. Lett. 33, 1074-1076 (2008)