Abstract: Methods and systems are described that enable manufacturing of holograms with high spatial frequencies and allow composite master holograms to be formed in reflection configurations. An example system for replicating transmission-type holographic elements includes one or more prisms positioned to receive an illumination beam on a first face. A composite master holographic element is positioned in contact with a second face of the one or more prisms to receive the illumination beam after propagation through he one or more prisms. The composite master hologram includes a reference beam component and an object beam component. The replication hologram is positioned in contact with a third face of the one or more prisms to receive, upon illumination of the master HOE by the illumination beam, a holographic exposure comprising first order diffracted illumination from both the reference beam component and object beam component at an exposure region of the copy HOE.

Abstract: Provided are methods for replication (copying) of volume Holographic Optical Elements (HOE) using a master hologram in optical contact with a prism, wherein the master hologram comprises distinct object and reference beam coupling elements, and wherein in the replication process light is coupled from one face of the prism and transmitted through another face of the prism using the distinct object and reference beam coupling elements. Methods for making the master hologram by sequentially forming the distinct object and reference beam coupling elements therein are provided. Further methods for encoding aperture functions directly to the master hologram are provided. Yet further methods provide for forming a copy HOE in an array configuration using a step-and-repeat method wherein the copy HOE is translated laterally by a specified distance before the next exposure is made.

Abstract: A photovoltaic module comprises one or more spectrum splitting devices disposed adjacent a first side of the photovoltaic module; and a plurality of photovoltaic cells disposed adjacent a second side of the photovoltaic module opposite the first side and such that the photovoltaic cells are spaced from the one or more spectrum splitting devices, wherein at least one of the photovoltaic cells comprise a bifacial photovoltaic cell, wherein the one or more spectrum splitting devices are configured to selectively direct incident energy to one or more of the photovoltaic cells, and wherein a spatial configuration of the one or more spectrum splitting devices and the plurality of photovoltaic cells are configured based on an optimization parameter.

Abstract: Provided are methods for replication (copying) of volume Holographic Optical Elements (HOE) using a master hologram in optical contact with a prism, wherein the master hologram comprises distinct object and reference beam coupling elements, and wherein in the replication process light is coupled from one face of the prism and transmitted through another face of the prism using the distinct object and reference beam coupling elements. Methods for making the master hologram by sequentially forming the distinct object and reference beam coupling elements therein are provided. Further methods for encoding aperture functions directly to the master hologram are provided. Yet further methods provide for forming a copy HOE in an array configuration using a step-and-repeat method wherein the copy HOE is translated laterally by a specified distance before the next exposure is made.

Abstract: The present disclosure describes a solar system comprising a bi-facial photo-voltaic module comprising one or more solar cells disposed adjacent a transparent encapsulant, the bifacial photo-voltaic module disposed in a substantially vertical configuration relative to a horizon and a holographic optical element disposed adjacent an end of the bi-facial photo-voltaic module, the holographic optical element configured to direct incident light toward one or more surfaces of the bi-facial photo-voltaic module.

Abstract: A solar PV module is disclosed having two types of laterally-separated coplanar cells with different bandgaps to improve conversion efficiency. A diffracting entrance window directs sunlight with wavelengths shorter than a separation 5 wavelength ks is directed largely to the first type of wider bandgap cells. Sunlight with wavelengths longer than a separation wavelength ks is directed largely to the second type of narrower bandgap cells. The separation wavelength is chosen so that each cell is illuminated largely by that part of the solar spectrum to which it has the higher conversion efficiency, resulting in an overall conversion efficiency higher than 10 for either type of cell used alone. The wider bandgap cells are configured on a planar support in separated parallel strips, with the narrower bandgap cells largely filling the area between these strips.

Abstract: A solar PV module is disclosed having two types of laterally-separated coplanar cells with different bandgaps to improve conversion efficiency. A diffracting entrance window directs sunlight with wavelengths shorter than a separation 5 wavelength ks is directed largely to the first type of wider bandgap cells. Sunlight with wavelengths longer than a separation wavelength ks is directed largely to the second type of narrower bandgap cells. The separation wavelength is chosen so that each cell is illuminated largely by that part of the solar spectrum to which it has the higher conversion efficiency, resulting in an overall conversion efficiency higher than 10 for either type of cell used alone. The wider bandgap cells are configured on a planar support in separated parallel strips, with the narrower bandgap cells largely filling the area between these strips.

Abstract: An apparatus for obtaining energy from a polychromatic energy source that emits radiation in a first and a second wavelength band comprises a reflector or an energy receiver having an aperture therein; and a holographic lens that diffracts and focuses the radiation within the first wavelength band from the energy source through said aperture towards a first energy receiver, and transmits the radiation within the second wavelength band from the energy source to the reflector or energy receiver. If a reflector is used, the reflector reflects the radiation transmitted by the holographic lens towards a second energy receiver.

Abstract: A confocal rainbow holographic imaging system and hologram fabrication method. The system employs a multi-spectral light source, a multiple grating volume hologram and a dual pass illumination and imaging pathway which provide for depth sectioning of an object, coverage of the full FOV of the system, and high lateral and depth resolution. Dual matched holograms are used to provide a high image contrast ratio. A method for fabricating the holograms employ a novel combination of design tools is also provided.

Abstract: A volume holographic imaging system, apparatus, and/or method enables the projection of a two-dimensional (2D) slice of a four-dimensional (4D) probing object. A 4D probing source object is illuminated to emit or scatter an optical field. A holographic element having one or more recorded holograms receives and diffracts the optical field into a diffracted plane beam having spectral information. A 4-f telecentric relay system includes a pupil filter on the relayed conjugate plane of the volume hologram and images the pupil of the volume hologram onto the front focal plane of the collector lens. A collector lens focuses the diffracted plane beam to a 2D slice of the 4D probing source object. The focused 2D slice is projected onto a 2D imaging plane. The holographic element may have multiple multiplexed holograms that are arranged to diffract light from the corresponding slice of the 4D probing source object.

Abstract: Provided are modular volume holographic imaging system (VHIS) endoscopic systems, comprising: an endoscope attachment module having a microscope objective lens, a single or cascaded compensated relay system configured to preserve an optical wavefront for use with a single or multiplexed volume hologram to select wavefronts originating from different object depths, and a system aperture; and a handle module configured to be reversibly attachable for operative communication with the endoscope attachment module, and having a beam splitter; a relay having adjustable spacing for object space focus compensation, and a single or multiplexed volume hologram suitable in operation to select wavefronts originating from different object depths, and wherein the handle module is further configured for operative communication with an illumination source and imaging optics. Preferably, an illumination module and an imaging module are configured to be in operative, reversibly attachable communication with the handle module.

Abstract: A volume holographic imaging system, apparatus and/or method enables the projection of a two-dimensional (2D) slice of a four-dimensional (4D) probing object A 4D probing source object is illuminated to emit or scatter an optical field. A holographic element having one or more recorded holograms receives and diffracts the optical field into a diffracted plane beam having spectral information. A 4-ftelecentric relay system includes a pupil filter on the relayed conjugate plane of the volume hologram and images the pupil of the volume hologram onto the front focal plane of the collector lens. A collector lens focuses the diffracted plane beam to a 2D slice of the 4D probing source object. The focused 2D slice is projected onto a 2D imaging plane. The holographic element may have multiple multiplexed holograms that are arranged to diffract light from the corresponding slice of the 4D probing source object.

Abstract: Provided are modular volume holographic imaging system (VHIS) endoscopic systems, comprising: an endoscope attachment module having a microscope objective lens, a single or cascaded compensated relay system configured to preserve an optical wavefront for use with a single or multiplexed volume hologram to select wavefronts originating from different object depths, and a system aperture; and a handle module configured to be reversibly attachable for operative communication with the endoscope attachment module, and having a beam splitter; a relay having adjustable spacing for object space focus compensation, and a single or multiplexed volume hologram suitable in operation to select wavefronts originating from different object depths, and wherein the handle module is further configured for operative communication with an illumination source and imaging optics. Preferably, an illumination module and an imaging module are configured to be in operative, reversibly attachable communication with the handle module.

Abstract: An apparatus for obtaining energy from a polychromatic energy source that emits radiation in a first and a second wavelength band comprises a reflector or an energy receiver having an aperture therein; and a holographic lens that diffracts and focuses the radiation within the first wavelength band from the energy source through said aperture towards a first energy receiver, and transmits the radiation within the second wavelength band from the energy source to the reflector or energy receiver. If a reflector is used, the reflector reflects the radiation transmitted by the holographic lens towards a second energy receiver.

Abstract: A confocal rainbow holographic imaging system and hologram fabrication method. The system employs a multi-spectral light source, a multiple grating volume hologram and a dual pass illumination and imaging pathway which provide for depth sectioning of an object, coverage of the full FOV of the system, and high lateral and depth resolution. Dual matched holograms are used to provide a high image contrast ratio. A method for fabricating the holograms employ a novel combination of design tools is also provided.

Abstract: A volume holographic imaging system, apparatus, and/or method enables the projection of a two-dimensional (2D) slice of a four-dimensional (4D) probing object A 4D probing source object is illuminated to emit or scatter an optical field A holographic element having one or more recorded holograms receives and diffracts the optical field into a diffracted plane beam having spectral information A 4-ftelecent?c relay system includes a pupil filter on the relayed conjugate plane of the volume hologram and images the pupil of the volume hologram onto the front focal plane of the collector lens A collector lens focuses the diffracted plane beam to a 2D slice of the 4D probing source object The focused 2D slice is projected onto a 2D imaging plane The holographic element may have multiple multiplexed holograms that are arranged to diffract light from the corresponding slice of the 4D probing source object.