ABSTRACT
In this chapter, the authors review the progresses in the design and simulation of three classes of metal heterostructures: metal gap heterowaveguides, planar metal heterostructures, and ridged metal heterostructures for the realizations of nanofocusing, nanoguiding, directional beaming of light, and enhancement of local electromagnetic field. They demonstrate that surface plasmon polariton modes (SPPs) resonance can also be engineered by dielectric properties of metal materials and highly directional beaming of light from a nanoslit surrounded by Al-Ag constructed metal heterostructures can be achieved. SPPs-based structures are widely regarded as feasible candidates in constructing novel waveguides with nanometric cross section. It should be pointed out that the proposed metal nanoslit heterostructures can be extended to 2D cases where the beaming effect can be realized through a hole surrounded by annular metal heterostructures constructed with metals Al and Ag.
