Long-Range Surface Plasmon Polaritons Guided by a Thin Metal Stripe

A long-range surface plasmon polariton (LRSPP) waveguide consisting of a
15nm thick gold stripe embedded in a homogeneous polymer BCB is reported. LRSPPs are excited by TM-mode input light successfully using an end-fire method. By scanning the output coupling fibre, the near field of the LRSPP is measured. The propagation loss of as low as 2.34dB/mm is demonstrated.