Characterization of radiance from the ocean surface by hyperspectral imaging.

A novel snapshot hyperspectral imager is introduced for ocean color (OC) applications and its capabilities are demonstrated. The instrument provides hyperspectral radiance images with a wide field-of-view (FOV) and short exposure time, which is valuable for the direct characterization of the wind-roughened surface in various illumination conditions and wind speeds. Uncertainties in the total(L), sky (L) and derived water-leaving (L)radiances at viewing angles of 20-60° are determined as a function of wind speed together with associated correlation coefficients and variances of the sea surface reflectance coefficient ρ.

Dispersion engineering of surface plasmons.

In this work, it is shown how the shapes of surface plasmon dispersion curves can be engineered by manipulating the distribution of the electromagnetic fields in multilayer structures, which themselves are controlled by the free electron density in metal-like materials, such as doped semiconductors in the THz spectral range. By having a nonuniform free electron density profile, reduced relative to that in typical bulk metals, the electromagnetic fields of surface plasmons are distributed in different metallic materials that have different complex dielectric permittivities. As the in-plane component of surface plasmon's wave-vector increases, they become more confined to a particular layer of the multilayer structure and have energies that are predictable by considering the permittivity of the layer in which the fields are most concentrated.

The light filtering and guiding properties of high finesse phase resonant compound gratings.

Phase resonances in compound gratings are studied in the frequency and time domains, with the gratings having two dissimilar grooves within the unit cell that each support waveguide cavity modes that couple. Described in this work are the dependence of the phase resonances' Q on the degree of difference between the grooves in the unit cell, their optical properties, a closed-form expression describing their dispersion, their excitation, and the extraction of energy from the phase resonances into free space and into a waveguide. Application to optical filters and corrugated surface antennas are discussed.

Aligned Layers of Silver Nano-Fibers.

We describe a new dichroic polarizers made by ordering silver nano-fibers to aligned layers. The aligned layers consist of nano-fibers and self-assembled molecular aggregates of lyotropic liquid crystals. Unidirectional alignment of the layers is achieved by means of mechanical shearing.

Electro-Optic Effects in Colloidal Dispersion of Metal Nano-Rods in Dielectric Fluid.

In modern transformation optics, one explores metamaterials with properties that vary from point to point in space and time, suitable for application in devices such as an "optical invisibility cloak" and an "optical black hole". We propose an approach to construct spatially varying and switchable metamaterials that are based on colloidal dispersions of metal nano-rods (NRs) in dielectric fluids, in which dielectrophoretic forces, originating in the electric field gradients, create spatially varying configurations of aligned NRs. The electric field controls orientation and concentration of NRs and thus modulates the optical properties of the medium.