Plasmonic photonic crystal with a complete band gap for surface plasmon polariton waves

A dielectric plasmonic photonic crystal for manipulating surface plasmon polariton (SPP) fields has been designed, fabricated, and tested. The band structure of SPP fields inside the plasmonic photonic crystal has been calculated using the plane wave expansion method and validated by full wave numerical simulations. The fabricated device was characterized using our far-field SPP imaging technique. The transmittance of incident SPP waves is about 5% at 1520 nm (a designed band gap frequency), confirming the designed band structure. The results show, both experimentally and theoretically, a complete two-dimensional band gap for in-plane SPP waves. The SPP fields at frequencies within this specified 0.14ωa/2πc-wide band gap frequency range are forbidden to propagate through the plasmonic photonic crystal.