Abstract: A method for imaging tissue is provided. The method includes illuminating a target tissue via a light-emitting diode. The method further includes acquiring a plurality of timed images of the target tissue including an excitation image corresponding to an excitation state of the light-emitting. Additionally, the method includes generating a relative lifetime map of the target tissue based on the plurality of timed images.

Abstract: Systems and methods for biocompatible tissue characterization using Raman imaging are provided. The systems and methods utilize Raman systems tuned to monitor spectral wavelengths characteristic of target types of tissue to monitor constituents of that tissue in biological systems and samples. The Raman systems may be tuned to monitor the Raman signature for the formation of the chemical bonds that join phosphorous and oxygen (PO) atoms, such that the formation of hydroxyapatite may be monitored and used to determine the presence of bone formation in a sample, such as, for example, biological tissue.

Abstract: A time-resolved fluorescence imaging (TRFI) system that images a target medium without lifetime fitting. Instead of extracting the lifetime precisely, the system images the fluorophore distribution to allow for a simple and accurate method to obtain the fluorescence image without lifetime-extraction for time-resolved fluorescence imaging. An illumination source circuit for TRFI is also disclosed that shapes the excitation pulse. In one embodiment, the illumination source comprises an LED and stub line configured for generating a linear decay profile.

Abstract: A structure includes multiple electromagnets with sub-100 micrometer feature size. Each electromagnet includes a substrate defining multiple filled trenches with conductive fillers, a first isolation layer disposed over the conductive fillers such that a portion of each conductive filler is exposed by the first isolation layer, a core disposed over the first isolation layer, and a second isolation layer covering the core. The second isolation layer has a top surface, and winding interconnects extend from a plane defined by the top surface of the second isolation layer to the conductive fillers such that each winding interconnect contacts one of the conductive fillers on a portion exposed by the first isolation layer. A conductive layer includes upper connectors to electrically connect winding interconnects positioned on opposite sides of the core. The trenches, winding interconnects, and upper connectors are electrically connected to form windings around the core.

Abstract: A time-resolved fluorescence imaging (TRFI) system that images a target medium without lifetime fitting. Instead of extracting the lifetime precisely, the system images the fluorophore distribution to allow for a simple and accurate method to obtain the fluorescence image without lifetime-extraction for time-resolved fluorescence imaging. An illumination source circuit for TRFI is also disclosed that shapes the excitation pulse. In one embodiment, the illumination source comprises an LED and stub line configured for generating a linear decay profile.

Abstract: A solar energy conversion system is presented. The system comprises at least one waveguide arrangement having at least one light input respectively. The waveguide arrangement comprises a core unit for passing input solar radiation therethrough and a cladding material arrangement interfacing with the core therealong. The cladding material arrangement is configured as an array of spaced-apart solar cells arranged along the core unit and having different optical absorption ranges, such that an interface between the waveguide core and the cladding arrangement spectrally splits the photons of the input solar radiation by causing the photons of different wavelengths, while passing through the core unit, to be successively absorbed and thereby converted into electricity by the successive solar cells of said array.

Abstract: A solar energy conversion system is presented. The system comprises at least one waveguide arrangement having at least one light input respectively. The waveguide arrangement comprises a core unit for passing input solar radiation therethrough and a cladding material arrangement interfacing with the core therealong. The cladding material arrangement is configured as an array of spaced-apart solar cells arranged along the core unit and having different optical absorption ranges, such that an interface between the waveguide core and the cladding arrangement spectrally splits the photons of the input solar radiation by causing the photons of different wavelengths, while passing through the core unit, to be successively absorbed and thereby converted into electricity by the successive solar cells of said array.

Abstract: A method and system for ranging an object are disclosed. The method includes illuminating a field of view potentially including the object, synchronously receiving reflected signals from the field of view with and without illumination, capturing first and second images within an array, and generating a subtraction image using the images. One image is captured in the array while the other image is in the array. The first and second images include reflected signals from the field of view with and without illumination, respectively. The array includes first and second groups of lines that are unmasked and masked, respectively. In one exposure, the first group of lines is loaded with the first or second image. The image in the first group of lines is shifted into the second group. In another exposure, the first group of lines is loaded with the other image, which is shifted into the second group.

Abstract: The claimed system measures the relative position of objects with retroreflective surfaces, such as those contained in the taillights of all cars, trucks, and motorcycles. This system comprises an illuminator operating in the visible or near-infrared waveband, one or more imagers, each placed behind an e.g. fixed-focus optical lens and a bandpass filter, and a microprocessor. The microprocessor runs the software that operates the illuminator and the imagers, and processes the data collected from the imagers to produce the ranging information. Each set of ranging data is obtained by recording two images, the first one with the illuminator turned off and the second one with the illuminator turned on, and then subtracting the first image from the second one. The purpose of the subtraction process is to remove all data from the resulting image except for the returns of the retroreflective surfaces.

Abstract: Improved microsensors are provided by combining surface micromachined substrates, including integrated CMOS circuitry, together with bulk micromachined wafer bonded substrates which include at least part of a microelectromechanical sensing element. In the case of an accelerometer, the proof mass is included within the wafer bonded bulk machined substrate, which is bonded to the CMOS surface machine substrate, which has corresponding etch pits defined therein over which the wafer bonded substrate is disposed, and in the case of accelerometer, the proof mass or thin film membranes in the case of other types of detectors such as acoustical detectors or infrared detectors. A differential sensor electrode is suspended over the etch pits so that the parasitic capacitance of the substrate is removed from the capacitance sensor, or in the case of a infrared sensor, to provide a low thermal conductance cavity under the pyroelectric refractory thin film.

Abstract: Non-normal plane wave electromagnetic scattering from active guiding structures, such as dielectric films, generates large resonances at discrete plane-wave angles of incidence relative to an interface with the active film. These resonances are generated from a "leaky" wave phase matching condition. Enhancement in the scattered field intensities on the order of 100 is achieved using finite diameter pump and probe laser beams and active films as thin as 6 microns. Solid state and dye lasers with unique characteristics are obtained. Oscillators, amplifiers, gyroscopic and nonlinear laser applications employing the active guiding structure or film provide enhanced performance.

Abstract: Non-normal plane wave electromagnetic scattering from active guiding structures, such as dielectric films, generates large resonances at discrete plane-wave angles of incidance relative to an interface with the active film. These resonances are generated from a "leaky" wave phase matching condition. Enhancement in the scattered field intensities on the order of 100 is achieved using finite diameter pump and probe laser beams and active films as thin as 6 microns. Solid state and dye lasers with unique characteristics are obtained. Oscillators, amplifiers, cyroscopic and nonlinear laser applications employing the active guiding structure or film provide enhanced performance.

Abstract: A semiconductor device wafer base wherein devices may be fabricated in silicon carbide, the base having a compatible substrate and a beta silicon carbide overlay layer epitaxially related to the substrate, the beta silicon carbide layer being unpolytyped, single crystal, uncracked, without twins, and having integrated circuit quality surface morphology. Preferably, the substrate is a single crystal of titanium carbide, which is the same cubic lattice-type as beta silicon carbide with a lattice parameter different from that of beta silicon carbide by less than about 1%. Additionally, the thermal expansion coefficients of beta silicon carbide and titanium carbide are nearly the same, minimizing the creation of thermal stresses during cooling and heating. The beta silicon carbide is useful in fabricating semi-conductor devices for use at much higher temperatures than is silicon, and for use at high power levels, at high frequencies, and in radiation hardened applications.

Abstract: A semiconductor device wafer base wherein devices may be fabricated in silicon carbide, the base having a compatible substrate and a beta silicon carbide overlay layer epitaxially related to the substrate, the beta silicon carbide layer being unpolytyped, single crystal, uncracked, without twins, and having integrated circuit quality surface morphology. Preferably, the substrate is a single crystal of titanium carbide, which is the same cubic lattice-type as beta silicon carbide with a lattice parameter different from that of beta silicon carbide by less than about 1%. Additionally, the thermal expansion coefficients of beta silicon carbide and titanium carbide are nearly the same, minimizing the creation of thermal stresses during cooling and heating. The beta silicon carbide is useful in fabricating semiconductor devices for use at much higher temperatures than is silicon, and for use at high power levels, at high frequencies, and in radiation hardened applications.

Abstract: An RF excited metal waveguide laser wherein one of the two opposed electrodes forming the discharge region has its top surface thereof formed as a waveguide thus eliminating the dielectric sidewalls used in prior art metal waveguide lasers. In the preferred embodiment, an enclosure having metal sidewalls and bottom has one of the electrodes attached thereto and the opposite electrode is attached to a dielectric cover on the enclosure. The laser gas can be circulated through the entire enclosure to aid in the cooling of the electrodes. The preferred shape of the waveguide electrode is with a longitudinal and transverse concave radius of curvature.

Abstract: Disclosed herein is a process for growing II-IV semiconductor crystals which includes providing both a II-IV semiconductor source material and a crystal growth support member in a predetermined dynamic vacuum. This vacuum is sufficient to create a predetermined overpressure at the source material and simultaneously remove impurities therefrom. The temperature of the support member is initally raised to a predetermined level above the temperature of the source material to thereby prevent vapor transport between the two. Then, the temperature of the support member is lowered to a predetermined value below that of the source material to produce a disassociation of elemental gases from the source material and initiate controlled vapor transport of the elemental gases from the source material to the support member. In this manner, compound semiconductor crystals of high purity and stoichiometry are formed on the surface of the support member.

Abstract: The specification describes a process for growing selected compound semiconductors of high stoichiometry and purity and includes the steps of providing both a dynamic vacuum and a predetermined temperature profile in a container or tube containing a chosen semiconductor source material. The dynamic vacuum is used to create a predetermined minimum overpressure. P.sub.min, in this container with respect to the vapor pressure of the source material, while simultaneously removing impurities through in opening in the container during the crystal growth process. This process involves the vapor transport of elements of the selected compound semiconductor from the source material to a suitable support member, such as a graphite crucible which is maintained at a predetermined uniform controlled temperature.

Abstract: There is disclosed a polarizer particularly suited for use in the infrared wavelengths which comprises a wire grid polarizer in optically cascaded relationship with a Brewster's Angle Polarizer. Not only do the extinction ratios of the optically cascaded polarizers multiply to provide higher extinction ratios at these wavelengths, but also the reflective mirror properties of the wire grid polarizers can be used in combination with the known optical properties of Brewster Polarizers to provide a combined device which optimizes both the extinction ratios achieved and the balance between the reflection and recombination problem of the system on the one hand and the offset or beam walking problem on the other hand in a manner to provide optical characteristics which are not achievable from any simple combinations of either type of polarizer alone.

Abstract: Large, strain free, single crystals of high optical quality selected from the IB-VB-VIB and IIIB-VB-VIB ternary chalcogenide groups, having a single stable solid phase from room temperature to the melting point of the crystal and vice-versa, are synthesized by (1) placing stoichiometric quantities of the compound constituents with 3% excess VIB constituent in a two part, sublimation-reaction fused silica tube, the VB constituents being placed in sublimation part, and the remaining constituents being placed in the reaction part, and evacuating and sealing the tube, (2) subliming and purifying the VB constituent and condensing it in the reaction part, which is then cooled and sealed from the sublimation part, (3) reacting, uniting and slowly cooling the reaction part constituents, (4) placing the reacted constituents in fused silica growth tube, which is evacuated, backfilled with helium, and sealed, (5) forming a melt in the upper part of a two part furnace and lowering at about 1.8 mm/hr.