We demonstrate that a three-dimensional (3D) index-guided multimode plasmonic waveguide can be approximated to a two-dimensional (2D) lossy slab waveguide by using an effective-index method. It is found that this 2D approximation is more accurate when the width of the multimode waveguide increases. Such a 2D approximation can be used for a quicker and more efficient design of complicated multimode plasmonic devices.
© 2007 Optical Society of America
Original Manuscript: April 2, 2007
Revised Manuscript: June 25, 2007
Manuscript Accepted: July 9, 2007
Published: August 21, 2007
Zhanghua Han and Sailing He, "Two-dimensional model for three-dimensional index-guided multimode plasmonic waveguides and the design of ultrasmall multimode interference splitters," Appl. Opt. 46, 6223-6227 (2007)