Abstract: A vehicle (10) includes an infrared imaging system (11). The system includes an infrared camera (12) positioned in the center of the front grille of the vehicle. The infrared camera includes a window (13) that has a holographic fringe pattern (14) which cooperates with visible light rays (27, 47, 52, 57) to generate an image (29) that is visible at a location spaced from the vehicle. The visible image may, for example, be a trademark or other symbol identifying the manufacturer of the vehicle. Infrared radiation (31) passes through the element and the structure thereof without significant change, and is detected by an infrared detector (33). A visible image corresponding to the infrared radiation is ultimately displayed by a head up display (19) on a portion (16) of the vehicle windshield (17).

Abstract: An optical switch (11, 111, 211) includes a member (26) having a plurality of openings (31-42) therethrough which are arranged in a periodic pattern. A path (86-87, 91-92, 96-97) extends through the member from an input to an output, with a subset of the openings disposed along the path. In one operational mode, each of the openings contains a material having an index of refraction which is different from the index of refraction of the member, so as to define a photon band gap configuration that inhibits propagation through the member of radiation at a predetermined wavelength. In a different operational mode, the index of refraction of the subset of openings along the path has a different value, which permits radiation to propagate along the path.

Abstract: An infrared imaging system (10) includes a catheter (11). The catheter is inserted into a small passageway, such as a blood vein (23), in order to collect infrared information from the vein. The information is refracted by at least one lens (32, 46, 52, 57, 63) in a collecting section (17, 45, 56, 61) of the catheter, and is imaged onto the ends (38) of an array of optical fibers (34). The fibers transmit the information to a relay lens (42), which images the information onto respective detector elements of an infrared detector (12). The infrared detector converts the information received from the relay lens into electrical information, which is transmitted to a circuit (13). The circuit generates electrical data that is transmitted to a display (16), which displays a visible image based on the infrared radiation emitted by the scene.

Abstract: A vehicle (10) includes an infrared imaging system (11). The system includes an infrared camera (12) positioned in the center of the front grille of the vehicle. The infrared camera includes a window (13) that has a holographic fringe pattern (14) which cooperates with visible light rays (27, 47, 52, 57) to generate an image (29) that is visible at a location spaced from the vehicle. The visible image may, for example, be a trademark or other symbol identifying the manufacturer of the vehicle. Infrared radiation (31) passes through the element and the structure thereof without significant change, and is detected by an infrared detector (33). A visible image corresponding to the infrared radiation is ultimately displayed by a head up display (19) on a portion (16) of the vehicle windshield (17).

Abstract: An apparatus for processing optical signals includes a cladding material having therein at least two elongate core regions which serve as respective waveguides. A coupling portion therein includes adjacent and parallel portions of the two waveguides which extend sufficiently closely for a sufficient distance to permit coupling of radiation between these waveguide portions. Structure is provided that respectively permits and frustrates such coupling for respective component signals having respective different wavelengths. The coupling portion may optionally include an externally controlled switching section that can have a selected one of two states in which is respectively transmissive and nontransmissive to radiation.

Abstract: An infrared imaging system (10) includes a catheter (11). The catheter is inserted into a small passageway, such as a blood vein (23), in order to collect infrared information from the vein. The information is refracted by at least one lens (32, 46, 52, 57, 63) in a collecting section (17, 45, 56, 61) of the catheter, and is imaged onto the ends (38) of an array of optical fibers (34). The fibers transmit the information to a relay lens (42), which images the information onto respective detector elements of an infrared detector (12). The infrared detector converts the information received from the relay lens into electrical information, which is transmitted to a circuit (13). The circuit generates electrical data that is transmitted to a display (16), which displays a visible image based on the infrared radiation emitted by the scene.

Abstract: An optical dome or window formed of a composition which is transmissive to infrared frequencies in the range of from about 1 micron to about 14 microns and which is relatively opaque to substantially all frequencies above about 14 microns consisting essentially of a compound taken from the class consisting of group III-V compounds doped with an element taken from the class consisting of shallow donors and having less than about 1×107 atoms/cc impurities and having less than about 1×1015 parts carbon. The shallow donors are Se, Te and S, preferably Se, with the Se concentration from 5×1015 atoms/cc to 2×106 atoms/cc. The group III-V compound is preferably GaAs or GaP.

Abstract: An optical dome or window formed of a composition which is transmissive to infrared frequencies in the range of from about 1 micron to about 14 microns and which is relatively opaque to substantially all frequencies above about 14 microns consisting essentially of a compound taken from the class consisting of group III-V compounds doped with an element taken from the class consisting of shallow donors and having less than about 1×107 atoms/cc impurities and having less than about 1×1015 parts carbon. The shallow donors are Se, Te and S, preferably Se, with the Se concentration from 5×1015 atoms/cc to 2×1016 atoms/cc. The group III-V compound is preferably GaAs or GaP.

Abstract: An optical dome or window formed of a composition which is transmissive to infrared frequencies in the range of from about 1 micron to about 14 microns and which is relatively opaque to substantially all frequencies above about 14 microns consisting essentially of a compound taken from the class consisting of group III-V compounds doped with an element taken from the class consisting of shallow donors and having less than about 1×107 atoms/cc impurities and having less than about 1×1015 parts carbon. The shallow donors are Se, Te and S, preferably Se, with the Se concentration from 5×1015 atoms/cc to 2×1016 atoms/cc. The group III-V compound is preferably GaAs or GaP.

Abstract: An electro-optic system 10 is described which comprises an infrared sensor 12 and a processing unit 14 protected by a protective infrared transmissive window 16. The window 16 comprises a substrate layer 18 which may comprise gallium arsenide, zinc selenide, zinc sulfide or germanium. A protective layer 22 of gallium phosphide is formed outwardly from the substrate layer 18. An anti-reflective coating 20 is formed inwardly from substrate layer 18 and an outward anti-reflective coating 26 is formed outwardly from protective layer 22. The incorporation of protective layer 22 allows for excellent impact and wear resistance without interfering with the optical characteristics of the protective window 16.

Abstract: A protective, impact resistant material and method, the material comprising a fabric of thermoplastic polymeric fibers having a strength of at least 0.4 GPa and an elastic modulus of at least 5 GPa and a matrix of polymeric material disposed in the interstices between the fibers, the matrix having an elastic modulus in the range 0.2 to 3.times.10.sup.6 psi. The polymeric fibers can be gel spun polyethylene, polypropylene, nylon, polyvinyl alcohol and polyethylene terephthalate. In a second embodiment, the matrix is derived from the fabric.

Abstract: A method of making a protective coating material wherein there is provided a matrix of melted polymeric material transparent to energy of a predetermined type and having a predetermined melting temperature. A fabric of polymeric fibers having a melting temperature higher than the melting temperature of the matrix is placed in the matrix. The fibers are thermoplastic and have a strength of at least about 0.5 GPa (70,000 psi) and an elastic (Young's) modulus of at least about 25 GPa (3.6.times.10.sup.6 psi) and said matrix has an elastic modulus in the range from about 0.2 to about 3.times.10.sup.6 psi. A pressure of from about 1000 to about 2000 psi is applied to the fabric disposed in the matrix and then the temperature is raised to about and at least the melting temperature of the fabric for about the minimum time required to cause consolidation of the fabric and the matrix. The consolidated fabric and matrix are then rapidly cooled to a temperature below the melting temperature of the fabric.

Abstract: A composition of matter comprising a bulk material of uniform composition having first and second spaced apart surface regions and a dopant in the bulk material of progressively increasing concentration in a direction from the first to said second surface regions providing an interface intermediate the first and second surface regions wherein the portion of the bulk material on one side of the interface is electrically conductive and the portion of the bulk material on the other side of the interface is relatively electrically insulative. The bulk material is one of Ge, Si, group II-VI compounds and group III-V compounds and preferably GaAs or GaP. The dopant is a shallow donor for the bulk material involved and for GaAs and GaP is Se, Te or S. The ratio of the resistivity of the portion of the bulk material on one side of the interface to the portion of the bulk material on the other side of the interface is at least about 1:10.sup.7.

Abstract: A composition of matter comprising a bulk material of uniform composition having first and second spaced apart surface regions and a dopant in the bulk material of progressively increasing concentration in a direction from the first to said second surface regions providing an interface intermediate the first and second surface regions wherein the portion of the bulk material on one side of the interface is electrically conductive and the portion of the bulk material on the other side of the interface is relatively electrically insulative. The bulk material is one of Ge, Si, group II-VI compounds and group III-V compounds and preferably GaAs or Gap. The dopant is a shallow donor for the bulk material involved and for GaAs and GaP is Se, Te or S. The ratio of the resistivity of the portion of the bulk material on one side of the interface to the portion of the bulk material on the other side of the interface is at least about 1:10.sup.7.

Abstract: Thermal imaging chopper (20) may comprise a disk (40) formed of a thermally transmitting material. The disk (40) may include a structure (44) operable to randomly scatter thermal radiation of the scene (14).

Abstract: A protective, impact resistant material and method, the material comprising a fabric of thermoplastic polymeric fibers having a strength of at least 0.4 GPa and an elastic modulus of at least 5 GPa and a matrix of polymeric material disposed in the interstices between the fibers, the matrix having an elastic modulus in the range 0.2 to 3.times.10.sup.6 psi. The polymeric fibers can be gel spun polyethylene, polypropylene, nylon, polyvinyl alcohol and polyethylene terephthalate. In a second embodiment, the matrix is derived from the fabric.

Abstract: A protective, impact resistant material and method which includes a fabric of thermoplastic polymeric fibers having a strength of at least 0.5 GPa and an elastic modulus of at least 25 GPa and a matrix of polymeric material disposed in the interstices between the fibers having an elastic modulus of 0.2 to 3.times.10.sup.6 psi. The polymeric fibers can be gel spun, polyethylene, polypropylene, nylon, polyvinyl alcohol and polyethylene terephthalate. In a second embodiment, the matrix is derived from the fabric.

Abstract: An infrared lens assembly may comprise a lens set (32) including one or more refractive lenses. The refractive lens may be positioned along an optic axis (30) to receive infrared radiation. The lens set (32) may be designed to focus infrared radiation of a scene (14) at an image plane (15). An athermalization element (34) may be positioned along the optic axis (30) in optical communication with the lens set (32). The athermalization element (34) may include an infrared transmitting member (40) supporting a diffractive pattern (42). The infrared transmitting member (40) may comprise an infrared transmitting polymer. The diffractive pattern (42) may compensate for temperature induced changes in a focal length of the lens set (32) to maintain infrared radiation of the scene (14) in focus at the image plane (15).

Abstract: An optical dome or window formed of a composition which is transmissive to infrared frequencies in the range of from about 1 micron to about 14 microns and which is relatively opaque to substantially all frequencies above about 14 microns consisting essentially of a compound taken from the class consisting of group III-V compounds doped with an element taken from the class consisting of shallow donors and having less than about 1.times.10.sup.7 atoms/cc impurities and having less than about 1.times.10.sup.15 parts carbon. The shallow donors are Se, Te and S, preferably Se, with the Se concentration from 5.times.10.sup.15 atoms/cc to 2.times.10.sup.16 atoms/cc. The group III-V compound is preferably GaAs or GaP.

Abstract: An electro-optic system 10 is described which comprises an infrared sensor 12 and a processing unit 14 protected by a protective infrared transmissive window 16. The window 16 comprises a substrate layer 18 which may comprise gallium arsenide, zinc selenide, zinc sulfide or germanium. A protective layer 22 of gallium phosphide is formed outwardly from the substrate layer 18. An anti-reflective coating 20 is formed inwardly from substrate layer 18 and an outward anti-reflective coating 26 is formed outwardly from protective layer 22. The incorporation of protective layer 22 allows for excellent impact and wear resistance without interfering with the optical characteristics of the protective window 16.