Colloidal Self-Assembly of Silver Nanoparticle Clusters for Optical Metasurfaces.

Optical metasurfaces are two-dimensional assemblies of nanoscale optical resonators and could constitute the next generation of ultrathin optical components. The development of methods to manufacture these nanostructures on a large scale is still a challenge, while most performance demonstrations were obtained with lithographically fabricated metasurfaces that are restricted to small scales. Self-assembly fabrication routes are promising alternatives and have been used to produce original nanoresonators.

Propagation characteristics of single and multilayer Ga:ZnO in the epsilon near zero region.

We numerically investigated the propagation characteristics of Ga:ZnO (GZO) thin films embedded in a ZnWO background in the epsilon near zero (ENZ) region. We found that, for GZO layer thickness ranging between 2 - 100 nm (∼ 1/600 - 1/12 of ENZ wavelength), such structure supports a novel non-radiating mode with its real part of effective index lower than surrounding refractive index or even less than 1. Such a mode has its dispersion curve lying to the left of the light line in the background region.

Design of a compact and highly sensitive modal interferometer using hybrid modes of a dielectric loaded plasmonic waveguide.

We show the presence of hybridization between fundamental TE and first higher-order TM modes in a dielectric loaded plasmonic waveguide of appropriately chosen core dimensions. Furthermore, a critical hybridization point is achieved at which both modes have nearly equal fraction of the TE and TM polarizations. Exploiting the interference among such modes, we propose the design of a compact and highly sensitive modal interferometer.

An Ultra-Thin Near-Perfect Absorber via Block Copolymer Engineered Metasurfaces.

Producing ultrathin light absorber layers is attractive towards the integration of lightweight planar components in electronic, photonic, and sensor devices. In this work, we report the experimental demonstration of a thin gold (Au) metallic metasurface with near-perfect visible absorption (∼95 %). Au nanoresonators possessing heights from 5 - 15 nm with sub-50 nm diameters were engineered by block copolymer (BCP) templating.

Ultrahigh-sensitive temperature sensor based on modal interference in a metal-under-clad ridge waveguide with a polymer upper cladding.

We propose a highly sensitive temperature sensor based on modal interference in a metal-under-clad ridge waveguide (MUCRW) with polydimethylsiloxane as the upper cladding. The proposed sensor exploits the interference between the fundamental and the first higher order TE modes of the MUCRW. The increased fractional modal power in the ambient medium due to the metal under-cladding along with the high thermo-optic coefficient of the upper cladding results in a very significant change in the modal characteristics of the two interfering modes with temperature variation.