Abstract: A photovoltaic cell includes a junction, formed from an n-type semiconductor material and a p-type semiconductor material, a trench, opening toward the light-incident side of the junction, for trapping reflected light, and two photon conversion layers. A first photon conversion layer, arranged at the light-incident side of the junction, converts photons from a higher energy to a lower energy suitable for absorption by the semiconductor material, and a second photon conversion layer, arranged at the opposite side of the junction, converts photons from a lower energy to a higher energy suitable for absorption by the semiconductor material.

Abstract: A semiconductor junction may include a first layer and a second layer. The first layer may include a first semiconductor material and the second layer may be deposited on the first layer and may include a second material. The valence band maximum of the second material is higher than a conduction band minimum of the first semiconductor material, thereby allowing a flow of a majority of free carriers across the semiconductor junction between the first and second layers to be diffusive.

Abstract: A photovoltaic cell includes a junction, formed from an n-type semiconductor material and a p-type semiconductor material, a trench, opening toward the light-incident side of the junction, for trapping reflected light, and two photon conversion layers. A first photon conversion layer, arranged at the light-incident side of the junction, converts photons from a higher energy to a lower energy suitable for absorption by the semiconductor material, and a second photon conversion layer, arranged at the opposite side of the junction, converts photons from a lower energy to a higher energy suitable for absorption by the semiconductor material.

Abstract: A photovoltaic cell includes a junction, formed from an n-type semiconductor material and a p-type semiconductor material, a trench, opening toward the light-incident side of the junction, for trapping reflected light, and two photon conversion layers. A first photon conversion layer, arranged at the light-incident side of the junction, converts photons from a higher energy to a lower energy suitable for absorption by the semiconductor material, and a second photon conversion layer, arranged at the opposite side of the junction, converts photons from a lower energy to a higher energy suitable for absorption by the semiconductor material.

Abstract: A hollow-core waveguide structure for guiding an electromagnetic signal, comprising: a core material comprising a predetermined refractive index; and a cladding structure disposed about the core material, wherein the cladding structure has a refractive index that is less than unity; wherein the cladding structure comprises an Epsilon-near-zero (ENZ) metamaterial. The core material comprises air or the like. The cladding structure comprises one of substantially planar sheets disposed about the core material and a substantially tubular structure disposed about the core material. Optionally, the ENZ metamaterial comprises a plurality of nanostructures disposed in a host medium. The plurality of nanostructures comprise a transparent conducting oxide. Alternatively, the cladding structure is manufactured via a self-assembly method.

Abstract: A semiconductor junction may include a first layer and a second layer. The first layer may include a first semiconductor material and the second layer may be deposited on the first layer and may include a second material. The valence band maximum of the second material is higher than a conduction band minimum of the first semiconductor material, thereby allowing a flow of a majority of free carriers across the semiconductor junction between the first and second layers to be diffusive.

Abstract: A hollow-core waveguide structure for guiding an electromagnetic signal, comprising: a core material comprising a predetermined refractive index; and a cladding structure disposed about the core material, wherein the cladding structure has a refractive index that is less than unity; wherein the cladding structure comprises an Epsilon-near-zero (ENZ) metamaterial. The core material comprises air or the like. The cladding structure comprises one of substantially planar sheets disposed about the core material and a substantially tubular structure disposed about the core material. Optionally, the ENZ metamaterial comprises a plurality of nanostructures disposed in a host medium. The plurality of nanostructures comprise a transparent conducting oxide. Alternatively, the cladding structure is manufactured via a self-assembly method.

Abstract: A metamaterial-based dispersion compensator includes a plurality of layers arranged in a geometric structure; wherein the plurality of layers comprise engineered metamaterials; wherein the engineered metamaterials and the geometric structure are configured to compensate dispersion across a wavelength spectrum. The metamaterial-based dispersion compensator utilizes a specifically engineered frequency response, in a compact metamaterial form-factor, to correct for naturally occurring and problematic dispersion in physical systems such as in optical communication systems.

Abstract: A photovoltaic cell includes a junction, formed from an n-type semiconductor material and a p-type semiconductor material, a trench, opening toward the light-incident side of the junction, for trapping reflected light, and two photon conversion layers. A first photon conversion layer, arranged at the light-incident side of the junction, converts photons from a higher energy to a lower energy suitable for absorption by the semiconductor material, and a second photon conversion layer, arranged at the opposite side of the junction, converts photons from a lower energy to a higher energy suitable for absorption by the semiconductor material.

Abstract: A metamaterial-based dispersion compensator includes a plurality of layers arranged in a geometric structure; wherein the plurality of layers comprise engineered metamaterials; wherein the engineered metamaterials and the geometric structure are configured to compensate dispersion across a wavelength spectrum. The metamaterial-based dispersion compensator utilizes a specifically engineered frequency response, in a compact metamaterial form-factor, to correct for naturally occurring and problematic dispersion in physical systems such as in optical communication systems.

Abstract: A photovoltaic cell includes a junction, formed from an n-type semiconductor material and a p-type semiconductor material, a trench, opening toward the light-incident side of the junction, for trapping reflected light, and two photon conversion layers. A first photon conversion layer, arranged at the light-incident side of the junction, converts photons from a higher energy to a lower energy suitable for absorption by the semiconductor material, and a second photon conversion layer, arranged at the opposite side of the junction, converts photons from a lower energy to a higher energy suitable for absorption by the semiconductor material.

Abstract: A strongly anisotropic photonic crystal structure was designed using form birefringence. It has a low group velocity close to a split band edge (SBE) and large field enhancements proportional to the fourth power of the number of periods are predicted. The structure is used to amplify wireless signals outside and near the structure.

Abstract: A non-invasive spectral measurement of a native, diagnostic or treatment component in blood or tissue, illuminates the back of the eye and collects return light that has passed through and been reflected from choroidal or retinal tissue. Spectral analysis detects a retinal tissue state, or detects the level of a blood or serum constituent, which may be a native constituent or a dye, marker or pharmacological agent. Time-resolved or spectral decay monitoring may be used to assess organ functioning, e.g., by administering a serum-carried indicator of uptake, clearance or binding rate for specific organs. Circulating cells or material diagnostic of different conditions may also be detected by spectral analysis, either directly, or by tagging with a suitable label.

Abstract: New on-axis, optically addressable spatial light modulators (SLMs) and methods of use are described. The new SLMs include a film of a photochromic material and a non-polarizing beam splitter arranged such that read and write beams counterpropagate with one another, and the read beam is separated from the path of the write beam after being transmitted through the photochromic material film without losing any polarization information encoded on the read beam. The new SLMs are advantageously implemented in incoherent-to-coherent optical converters and all-optical joint transform correlators.