The closed form of the complete far-field asymptotic series is provided for the scalar and electromagnetic monochromatic fields in free space whose angular spectrum is smooth over the sphere of directions. The first few terms of this series are also shown to give corrections to the Fraunhofer diffraction formula. The application of this series is illustrated with two examples corresponding to a highly focused radially polarized field and to the scalar diffraction from a circular aperture.
© 2006 Optical Society of America
Original Manuscript: June 1, 2006
Manuscript Accepted: July 20, 2006
Published: September 25, 2006
Miguel A. Alonso and Riccardo Borghi, "Complete far-field asymptotic series for free fields," Opt. Lett. 31, 3028-3030 (2006)