Metal–Insulator–Metal Surface Plasmon Polariton Waveguide Filters With Cascaded Transverse Cavities

In this work we propose a new approach for the design of resonant structures aiming at wavelength filtering applications. The structure consists of a subwavelength metal-insulator-metal (MIM) waveguide presenting cascaded cavities transversely arranged in the midpoint between the input and output ports. An extra degree of freedom added to this design consists in tilting the cavities around their midpoints which, besides effectively increasing the quality factor of the cavity, helps extending its range of applications by tuning multiple wavelengths.