A theory for focused optical beams at planar structures is described. It is an extension of a previous theory based on summation of plane waves. The focused beam is obtained by an imaginary shift in the position vector of the plane waves. It is well suited for calculations of electromagnetic fields at planar surface plasmon resonance structures excited by a focused optical beam.
© 2007 Optical Society of America
Original Manuscript: December 5, 2006
Revised Manuscript: April 15, 2007
Manuscript Accepted: April 26, 2007
Published: July 11, 2007
Nils Calander, "Focused optical beams obtained at planar structures by an imaginary shift in position," J. Opt. Soc. Am. A 24, 2513-2515 (2007)