Efficient Excitation of Gap Plasmon Polaritons via Higher-Order Propagating Modes
Abstract
Efficient excitation of gap plasmon polaritons (GPPs) in an aluminum tapered gap is numerically investigated. Surface plasmon polaritons (SPPs) are efficiently excited via higher-order propagating modes by fabricating a pair of grooves on the internal surface of the tapered gap and the SPPs then be coupled into GPPs in the tip region. The physical mechanism and influence of the critical structure parameters such as groove location, groove depth, groove width and the taper angle are discussed. Based on the compression of the GPPs, a field enhancement of about 5000-fold is obtained at a 5 nm aperture.
- Publication:
-
Applied Physics Express
- Pub Date:
- September 2013
- DOI:
- 10.7567/APEX.6.092001
- Bibcode:
- 2013APExp...6i2001C