Abstract: The system and method of the present invention relates to using spectroscopy, for example, Raman spectroscopic methods for diagnosis of tissue conditions such as vascular disease or cancer. In accordance with a preferred embodiment of the present invention, a system for measuring tissue includes a fiber optic probe having a proximal end, a distal end, and a diameter of 2 mm or less. This small diameter allows the system to be used for the diagnosis of coronary artery disease or other small lumens or soft tissue with minimal trauma. A delivery optical fiber is included in the probe coupled at the proximal end to a light source. A filter for the delivery fibers is included at the distal end. The system includes a collection optical fiber (or fibers) in the probe that collects Raman scattered radiation from tissue, the collection optical fiber is coupled at the proximal end to a detector. A second filter is disposed at the distal end of the collection fibers.

Abstract: The invention relates to methods of identifying and characterizing properties of polymers to provide information about the polymer such as the charge of the polymer, the number and types or characteristics of units of the polymer and the sequence of the polymers. The invention also relates to methods of sequencing polymers such as nucleic acids, polypeptides and polysaccharides and methods for identifying a polysaccharide-protein interaction.

Abstract: The present invention relates to a fluorescence endoscope imaging system. The system uses first and second light sources to provide fluorescence and reflectance images of tissue being examined. An imaging device mounted at the distal end of the device is used to collect both images.

Abstract: A mode coupler that enables low-loss coupling between optical modes of two waveguides with different index difference. The mode size and the effective index are gradually changed between two waveguides to gradually transform the mode shape, size, and speed with minimum power loss. The mode coupler is useful for coupling the mode of an optical fiber waveguide with low index difference to the mode of a planar high index difference waveguide, and vice versa.

Abstract: A solid state electrochemical light-emitting device has a high maximum luminance, a high external efficiency, a long half-life, and a low operating voltage. The device includes a solid layer of metal complex distributed in a polymer matrix. The solid layer is contacted by electrodes on each surface. An applied potential across the electrodes generates light with a luminance of at least 30 cd/m2. The light-emitting device can have external quantum efficiencies of at least 2.0%. A light-emitting circuit including an AC voltage waveform generator coupled to the electrodes of the device is also described.

Abstract: A new mold solves problems that arise from differential changes in geometry inherent to casting metal in a ceramic mold, by control of the internal morphology between the surfaces of the mold that face the casting, and that face the external environment. Layered fabrication techniques are used to create a ceramic mold. For example, an internal geometry composed of a cellular arrangement of voids may be created within the mold wall. Structures may be designed and fabricated so that the ceramic mold fails at an appropriate time during the solidification and/or cooling of the casting. Thus, the casting itself is not damaged. The mold fails to avoid rupture, or even distortion, of the casting. A thin shell of ceramic defines the casting cavity. This shell must be thin enough to fail due to the stresses induced (primarily compressive) by the metal next to it and partly adherent to it.

Abstract: Remote, non-verbal interpersonal communication is facilitated between communication stations located remotely from each other. A first communication station registers proximity of a user thereto and communicates to a second communication station a signal indicative of the registered proximity. The first communication station also registers a physical gesture and communicates a signal indicative of the gesture to the second communication station. The second communication station, in turn, receives the signals and, in response thereto, produces a visual output indicative of proximity and of the gestural input.

Abstract: A carrier pocket engineering technique used to provide superlattice structures having relatively high values of the three-dimensional thermoelectric figure of merit (Z3DT) is described. Also described are several superlattice systems provided in acordance with the carrier pocket engineering technique. Superlattice structures designed in accordance with this technique include a plurality of alternating layers of at least two different semiconductor materials. First ones of the layers correspond to barrier layers and second ones of the layers correspond to well layers but barrier layers can also work as well layers for some certain carrier pockets and vice-versa. Each of the well layers are provided having quantum well states formed from carrier pockets at various high symmetry points in the Brillouin zone of the structure to provide the superlattice having a relatively high three-dimensional thermoelectric figure of merit.

Abstract: A high definition radar imaging system receives SAR image data and adaptively processes the image the data to provide a high resolution SAR image. The imaging technique employs an adaptive filter whose tap weights are computed based upon a constrained Maximum Likelihood Method (MLM). The MLM technique chooses the filter tap weights (i.e., a weighting vector &ohgr;) to satisfy several criteria including: 1) they preserve unity gain for a point scatter at the desired location, and 2) they minimize the perceived energy in the output image. The weights &ohgr; are constrained in norm ∥&ohgr;∥≦&bgr;, to reduce the loss of sensitivity to bright scatters. Significantly, the present invention applies an additional constraint on the iterative selection of the weighting vector &ohgr;, such that the weighting vector &ohgr; shall confined to a particular subspace in order to preserve background information in the image.

Abstract: A condensed matter structure includes a substrate having a resonant microcavity formed by reflectors, having a reflectivity R, arranged relative to an optically-active material to form a cavity. The optically-active material has a thickness L, an optical emission line centered at a wavelength &lgr;c, and an optical absorption coefficient &agr;0 at &lgr;c. The magnitude of absorption (&agr;0L) at &lgr;c by the optically-active material is greater than the probability (1−R) that an electromagnetic field having an energy of &lgr;c exits microcavity and thereby results in a strong light-matter interaction between the optically-active material and the electromagnetic field confined in the microcavity.

Abstract: The present invention relates to a class of luminescent and conductive polymer compositions having chromophores, and particularly solid films of these compositions exhibiting increased luminescent lifetimes, quantum yields and amplified emissions. These desirable properties can be provided through polymers having rigid groups designed to prevent polymer reorganization, aggregation or &pgr;-stacking upon solidification. These polymers can also display an unusually high stability with respect to solvent and heat exposures. The invention also relates to a sensor and a method for sensing an analyte through the luminescent and conductive properties of these polymers. Analytes can be sensed by activation of a chromophore at a polymer surface. Analytes include aromatics, phosphate ester groups and in particular explosives and chemical warfare agents in a gaseous state.

Abstract: An electromagnetic wavelength filter that allows the transmission of electromagnetic energy within a narrow range of wavelengths while reflecting incident electromagnetic energy at other wavelengths. The filter includes at least one cavity region; and at least two reflectors surrounding the at least one cavity region, at least one of the reflectors being an omni-directional reflector. The omni-directional reflector includes a structure with a surface and an index of refraction variation perpendicular to the surface, and the omni-directional reflector is specifically configured to exhibit high omni-directional reflection for a predetermined range of frequencies of incident electromagnetic energy for any angle of incidence and any polarization.

Abstract: A pulse-type beamforming apparatus, such as a radar array system, is used for receiving, detecting, localizing, and/or imaging desired signals. The apparatus is used to receive wideband chirp signals. The apparatus contains a receive aperture that is partitioned into multiple channels. The received signal at each channel is mixed with a replica chirp. The replica chirp is effectively delayed in a way that partially removes range-dependent distortion of desired signals. The mixer outputs are then sampled and filtered. The filters on each channel incorporate a time delay that completely removes the remaining range-dependent distortion for all signals in a desired direction. Signals are also compressed and integrated by a digital beamformer.

Abstract: The present invention relates to the use of polarized light to measure properties of tissue. More particularly, polarized light can be used to detect dysplasia in tissue as the polarization of back-scattered light from such tissues is preserved while the contribution of diffusely scattered light from underlying tissues can be removed. A fiber optic system for delivery and collection of light can be used to measure tissues within the human body.

Abstract: The current invention provides, in some embodiments, superconducting cryostat apparatuses, and methods for containing a coolant within the apparatuses and for cooling the apparatuses. The superconducting apparatuses provided by the invention include a self-contained supply of a coolant medium, which can be provided in the form of a pressurized gas. The mass of the coolant medium contained in the apparatus is conserved during operation of the apparatus. The superconducting cryostat apparatuses provided by the invention can be configured, in some embodiments, to eliminate the need for sources of external cooling during operation. The superconducting cryostat apparatuses provided by the invention can be cooled by supplying one or more sealable containers within the apparatuses with a quantity of cooling medium in gaseous form, and sealing the sealable containers.

Abstract: Channeled articles having very small diameter channels spaced very closely can be made by packing elongated cores in a fixture, clamping them, and then introducing matrix material around the cores. The matrix material is formed into a unitary body and solidified. The cores are pulled out, leaving open channels where they had been. Some core and matrix combinations will permit the cores to be pulled out. Others require a core release coating to be applied to the cores. The cores can be metal or ceramic or polymer, and the matrix can be metal or ceramic or polymer. The cores can be solid, or hollow. Rather than pulling the cores out, if they are polymer, they can be burned out. The matrix can be formed by liquid state, solid state, or hybrid liquid/solid state techniques. A related technique uses hollow cores, which are not pulled out, but which remain in the body after unification. For such tube-walled articles, the matrix can be formed similarly. Rather than insuring core release, core retention is required.

Abstract: The invention provides methods of charging superconducting materials and, in particular, methods of charging high-temperature superconducting materials. The methods generally involve cooling a superconducting material to a temperature below its critical temperature. Then, an external magnetic field is applied to charge the material at a nearly constant temperature. The external magnetic field first drives the superconducting material to a critical state and then penetrates into the material. When in the critical state, the superconducting material loses all the pinning ability and therefore is in the flux-flow regime. In some embodiments, a first magnetic field may be used to drive the superconducting material to the critical state and then a second magnetic field may be used to penetrate the superconducting material. When the external field or combination of external fields are removed, the magnetic field that has penetrated into the material remains trapped.

Abstract: Arrangements using air trench cladding enables minimization of the evanescent tail to suppress light coupling to radiation modes, resulting in low-loss bends and splitters. Structures including sharp bends and T-splitters without transmission loss, crossings without crosstalk, and couplers from/to fibers and with out-of-plane waveguides without substantial loss are provided with such air trench claddings. Air trench sidewall cladding of waveguides pushes evanescent tails toward top and bottom claddings to enhance coupling between vertically positioned waveguides. Fabrication processes using wafer bonding technology are also provided.

Abstract: A resonator system is disclosed for use in illuminating an input to a diffractive element. The system includes a source of an electromagnetic field having a wavelength of &lgr;, and first and second optical elements, each of which is at least partially reflecting. The first and second optical elements are separated from one another such that the optical path between the optical elements has a distance ( 2 ⁢ m + 1 ) ⁢ λ 4 , wherein m is an integer.

Abstract: A processing system having time-dependent combinatorial complexity is converted into a system having time-dependent periodic complexity.