We report a numerical study of plasmonic waveguides that localize light in two dimensions at a cross section of 4.2 nm×2.1 nm with the propagation length of 38 μm. By varying the geometrical parameters, strong mode confinements (range from λ2/3352 to λ2/2557525) are achieved with controllable propagation distance (44.68–40.988 μm), and mode size below 1 nm2 has been demonstrated for the first time. Furthermore, a cross-index-modulation mechanism is proposed to explain the strong field localization behavior, providing guidelines for future waveguide designs.
© 2012 Optical Society of America
Optics at Surfaces
Original Manuscript: December 23, 2011
Revised Manuscript: April 12, 2012
Manuscript Accepted: June 11, 2012
Published: July 12, 2012
Ran Hao, Erping Li, and Xingchang Wei, "Two-dimensional light confinement in cross-index-modulation plasmonic waveguides," Opt. Lett. 37, 2934-2936 (2012)