A procedure is proposed for generating rigorous closed-form orthonormal bases for the expansion of strongly focused (high-numerical-aperture), monochromatic, electromagnetic fields. The performance of three such bases is tested in terms of a parameter that determines their directional spread, for several truncation orders. Simple example fields corresponding to beams with differing polarizations focused by a thin lens are expanded in terms of these bases.
© 2009 Optical Society of America
Original Manuscript: July 13, 2009
Manuscript Accepted: August 21, 2009
Published: September 22, 2009
Nicole J. Moore and Miguel A. Alonso, "Closed-form bases for the description of monochromatic, strongly focused, electromagnetic fields," J. Opt. Soc. Am. A 26, 2211-2218 (2009)