Abstract: In general, in one aspect, the invention features an apparatus that includes a photonic crystal fiber configured to guide a mode of electromagnetic radiation at a wavelength, ?, along a waveguide axis. The fiber includes a core extending along the waveguide axis, and a confinement region extending along the waveguide axis and surrounding the core. The confinement region includes alternating layers of a first and a second dielectric material having thicknesses d1 and d2 and different refractive indices n1 and n2, respectively. The thickness of at least one of the alternating layers of the first material differs from thickness d1QW or at least one of the alternating layers of the second material differs from thickness d2QW, where d1QW and d2QW correspond to a quarter-wave condition for the two dielectric materials given by d1QW=?/(4?{square root over (n12?1)}) and d2QW=?/(4?{square root over (n22?1)}), respectively.

Abstract: In general, in one aspect, the invention features methods that include directing radiation to a target location of a patient through a photonic crystal fiber, the photonic crystal fiber having a hollow core and flowing a fluid through the hollow core to the target location of the patient.

Abstract: Systems and methods are provided for optimizing the geometric stretch of a parametrization scheme. Given an arbitrary mesh, the systems and methods construct a progressive mesh (PM) such that all meshes in the PM sequence share a common texture parametrization. The systems and methods minimize geometric stretch, i.e., small texture distances mapped onto large surface distances, to balance sampling rates over all locations and directions on the surface. The systems and methods also minimize texture deviation, i.e., “slippage” error based on parametric correspondence, to obtain accurate textured mesh approximations. The technique(s) begin by partitioning the mesh into charts using planarity and compactness heuristics. Then, the technique(s) proceed by creating a stretch-minimizing parametrization within each chart, and by resizing the charts based on the resulting stretch. Then, the technique(s) simplify the mesh while respecting the chart boundaries.

Abstract: Systems and methods are provided for providing a fine-to-coarse look ahead in connection with parametrization in a graphics system. The use of a variety of parametrization metrics may be supplemented and improved by the fine-to-coarse look ahead techniques of the invention. First, the metric of a parametrization is minimized using a coarse-to-fine hierarchical solver, and then accelerated with a fine-to-coarse propagation. The resulting parametrizations have increased texture resolution in surface regions with greater signal detail at all levels of detail in the progressive mesh sequence.

Abstract: In general, in a first aspect, the invention features photonic crystal fibers that include a core extending along a waveguide axis, a confinement region extending along the waveguide axis surrounding the core, and a cladding extending along the waveguide axis surrounding the confinement region, wherein the cladding has an asymmetric cross-section.

Abstract: In general, in one aspect, the invention features systems, including a photonic crystal fiber including a core extending along a waveguide axis and a dielectric confinement region surrounding the core, the dielectric confinement region being configured to guide radiation along the waveguide axis from an input end to an output end of the photonic crystal fiber. The systems also includes a handpiece attached to the photonic crystal fiber, wherein the handpiece allows an operator to control the orientation of the output end to direct the radiation to a target location of a patient.

Abstract: An optical waveguide including: a dielectric core region extending along a waveguide axis; and a dielectric confinement region surrounding the core about the waveguide axis, the confinement region comprising a photonic crystal structure having a photonic band gap, wherein during operation the confinement region guides EM radiation in at least a first range of frequencies to propagate along the waveguide axis, wherein the core has an average refractive index smaller than about 1.3 for a frequency in the first range of frequencies, and wherein the core a diameter in a range between about 4? and 80?, wherein ? is a wavelength corresponding to a central frequency in the first frequency range.

Abstract: Systems and methods are provided for optimizing a parametrization scheme in accordance with information about the surface signal. A surface parametrization is created to store a given surface signal into a texture image. The signal-specialized metric of the invention minimizes signal approximation error, i.e., the difference between the original surface signal and its reconstruction from the sampled texture. A signal-stretch parametrization metric is derived based on a Taylor expansion of signal error. For fast evaluation, the metric of the invention is pre-integrated over the surface as a metric tensor. The resulting parametrizations have increased texture resolution in surface regions with greater signal detail. Compared to traditional geometric parametrizations, the number of texture samples can often be reduced by a significant factor for a desired signal accuracy.

Abstract: An improved sensor array for a mobile vehicle. The vehicle includes a centerline parallel to a vehicle velocity vector. The sensor array comprises a first sensor mounted to the mobile vehicle at a maximum lateral distance from the centerline near a first side of mobile vehicle and a second sensor mounted to the mobile vehicle at a maximum lateral distance from the centerline near a second side of the vehicle opposite the first side. The first sensor transmits a forward pointing first beam and the second sensor transmits a forward pointing second beam, both beams for detecting an object in the path of the vehicle. A plurality of first oblique beams are pointed to intersect the first beam and a plurality of second oblique beams are pointed to intersect the second beam. The oblique beams, in conjunction with the first and second beams form zones of overlapping beam coverage for better localization of objects in the path of the vehicle.

Abstract: Systems and methods are provided for providing a fine-to-coarse look ahead in connection with parametrization in a graphics system. The use of a variety of parametrization metrics may be supplemented and improved by the fine-to-coarse look ahead techniques of the invention. First, the metric of a parametrization is minimized using a coarse-to-fine hierarchical solver, and then accelerated with a fine-to-coarse propagation. The resulting parametrizations have increased texture resolution in surface regions with greater signal detail at all levels of detail in the progressive mesh sequence.

Abstract: In general, in one aspect, the invention features an apparatus that includes a photonic crystal fiber configured to guide a mode of electromagnetic radiation at a wavelength, ?, along a waveguide axis. The fiber includes a core extending along the waveguide axis, and a confinement region extending along the waveguide axis and surrounding the core. The confinement region includes alternating layers of a first and a second dielectric material having thicknesses d1 and d2 and different refractive indices n1 and n2, respectively. The thickness of at least one of the alternating layers of the first material_differs from thickness d1QW or at least one of the alternating layers of the second material_differs from thickness d2QW, where d1QW and d2QW correspond to a quarter-wave condition for the two dielectric materials given by d1QW=?/(4{square root}{square root over (n12?1)}) and d2QW=?/(4{square root}{square root over (n22?1)}), respectively.

Abstract: In general, in one aspect, the invention features systems, including a photonic crystal fiber including a core extending along a waveguide axis and a dielectric confinement region surrounding the core, the dielectric confinement region being configured to guide radiation along the waveguide axis from an input end to an output end of the photonic crystal fiber. The systems also includes a handpiece attached to the photonic crystal fiber, wherein the handpiece allows an operator to control the orientation of the output end to direct the radiation to a target location of a patient.

Abstract: In general, in one aspect, the invention features apparatus that include an assembly including a radiation input port configured to receive radiation from a radiation source and an output port configured to couple the radiation to a photonic crystal fiber, the assembly further including a retardation element positioned to modify a polarization state of the radiation received from the radiation source before it is coupled to the photonic crystal fiber.

Abstract: In general, in one aspect, the invention features methods that include directing radiation to a target location of a patient through a photonic crystal fiber, the photonic crystal fiber having a hollow core and flowing a fluid through the hollow core to the target location of the patient.

Abstract: An improved sensor array for a mobile vehicle. More particularly, the primary objective of the present invention is to provide mobile vehicle (10) traveling in a forward direction with a sensor array (12). Sensor array (12) comprises a first sensor (16) mounted to mobile vehicle (10) at a maximum lateral distance from said vertical axis of rotation (21) near a first side of mobile vehicle (10) and a second sensor (18) mounted to mobile vehicle (10) at a maximum lateral distance from said vertical axis of rotation (21) near a second side of mobile vehicle (10). First sensor (16) and the second sensor (18) emit object detecting beams for detecting an object (39) ahead of mobile vehicle (10). A plurality of other object detecting beams are emitted obliquely to the object detecting beams of sensor (16) and sensor (18). These other beams, in conjunction with the object detecting beams from sensor (16) and sensor (18) form zones of overlapping beam coverage for better detection of objects.

Abstract: An optical waveguide having a working mode with a tailored dispersion profile, the waveguide including: (i) a dielectric confinement region surrounding a waveguide axis, the confinement region comprising a photonic crystal having at least one photonic bandgap, wherein during operation the confinement region guides EM radiation in a first range of frequencies to propagate along the waveguide axis; (ii) a dielectric core region extending along the waveguide axis and surrounded by the confinement region about the waveguide axis, wherein the core supports at least one guided mode in the first frequency range; and (iii) a dielectric dispersion tailoring region surrounded by the confinement region about the waveguide axis, wherein the dispersion tailoring region introduces one or more additional modes in the first range of frequencies that interact with the guided mode to produce the working mode.

Abstract: Systems and methods are provided for optimizing the geometric stretch of a parametrization scheme. Given an arbitrary mesh, the systems and methods construct a progressive mesh (PM) such that all meshes in the PM sequence share a common texture parametrization. The systems and methods minimize geometric stretch, i.e., small texture distances mapped onto large surface distances, to balance sampling rates over all locations and directions on the surface. The systems and methods also minimize texture deviation, i.e., “slippage” error based on parametric correspondence, to obtain accurate textured mesh approximations. The technique(s) begin by partitioning the mesh into charts using planarity and compactness heuristics. Then, the technique(s) proceed by creating a stretch-minimizing parametrization within each chart, and by resizing the charts based on the resulting stretch. Then, the technique(s) simplify the mesh while respecting the chart boundaries.

Abstract: In general, in one aspect, the invention features a waveguide that includes a first portion extending along a waveguide axis including a first chalcogenide glass, and a second portion extending along the waveguide axis including a second chalcogenide glass, wherein the second chalcogenide glass is different from the first chalcogenide glass.

Abstract: A method for estimating deceleration of a wheeled vehicle during a transmission gear shift. A first input signal indicative of an engine torque and a second signal indicative of an input shaft rotational speed are used to predict the expected vehicle deceleration during a transmission ratio shift to a target gear ratio. An expected vehicle deceleration value is outputted to a shift decision control unit for implementing a transmission gear shift.

Abstract: An optical waveguide including: a dielectric core region extending along a waveguide axis; and a dielectric confinement region surrounding the core about the waveguide axis, the confinement region comprising a photonic crystal structure having a photonic band gap, wherein during operation the confinement region guides EM radiation in at least a first range of frequencies to propagate along the waveguide axis, wherein the core has an average refractive index smaller than about 1.3 for a frequency in the first range of frequencies, and wherein the core a diameter in a range between about 4&lgr; and 80&lgr;, wherein &lgr; is a wavelength corresponding to a central frequency in the first frequency range.