Abstract: Methods and apparatus for measuring the modal bandwidth of a multimode optical fiber as a function of wavelength are disclosed. The methods include emitting polarized light from a single-mode fiber, frequency-modulating the single-mode polarized light, and then conditioning the frequency-modulated polarized light to excite multiple modes of the multimode optical fiber. The multimode light transmitted by the multimode optical fiber is detected and analyzed by a network analyzer to determine a bandwidth for at least three different wavelengths. A controller performs a fit to the measured bandwidths using a fitting equation to determine the modal bandwidth as a function of wavelength.

Abstract: An organic light emitting diode (OLED) device having enhanced light extraction is disclosed. The OLED device includes an upper waveguide structure having an organic layer and supports first guided modes, and a lower waveguide structure with a light-extraction waveguide that supports second guided modes substantially matched to the first guided modes. The lower waveguide structure includes a light-extraction waveguide interfaced with a light-extraction matrix. The light-extraction waveguide includes one or more light-redirecting features. The upper and lower waveguide structures are configured to facilitate mode coupling from the first guided modes to the second guide modes while substantially avoiding coupling the first guided modes to surface plasmon polaritons. The light traveling in the second guided modes is redirected to exit the OLED device by light-redirecting features of the light-extraction waveguide.

Abstract: A quantum key generation system including two photon detector units, two photon entanglement chains extending between the two photon detector units, and a plurality of multicore fiber links each including at least two non-uniform cores structurally configured to provide non-uniform photon propagation delay. Each photon entanglement chain includes at least one quantum repeater structurally configured to entangle a pair of photons and first and second terminating quantum memories optically coupled the quantum repeater using the multicore fiber links such that photons received by the first and the second terminating quantum memories are entangled with photons entangled by the quantum repeater.

Abstract: Durable antireflective coatings and glass articles having such coatings are described herein. The antireflective coatings generally include a layer of nominally hexagonally packed nanoparticles that are partially embedded either in a surface of the glass article or in a binder that is on the surface of the glass article. Methods of making the antireflective coatings or layers and glass articles having such antireflective layers are also described.

Abstract: Curved bezel-concealing display covers and display devices are disclosed. In one embodiment, a bezel-concealing display cover for coupling to a display device having a bezel and a display panel includes a curved perimeter portion having a first surface and a second surface, wherein the curved perimeter portion is configured to be offset from the bezel of the display device by a varying gap GA. The bezel-concealing display cover further includes an array of prisms on at least one of the first surface or the second surface of the curved perimeter portion. The array of prisms extends from an edge of the curved perimeter portion to a distance L. The array of prisms and the curved perimeter portion is configured to shift a portion of an image proximate the bezel produced by the display panel such that the shifted portion of the image appears over the bezel to an observer.

Abstract: A light collection and light guidance system including: a flat collecting sheet having a first roughened light receiving front surface; and a plurality of optical fibers attached to at least one edge of the flat collecting sheet, wherein the first roughened light receiving front surface of the sheet has a plurality of resonance coupling periodicities, a plurality of correlation lengths, or a combination thereof. Also disclosed is a method of light collection and light guidance using the aforementioned system, or a system including a flat collecting sheet and a solar converter, as defined herein.

Abstract: Methods and apparatus for providing one or more components for a display system, particularly for producing diffused light.

Abstract: An antireflection article including: a transparent substrate having a refractive index of from 1.48 to 1.53; a binder layer associated with the substrate, the binder having a refractive index of from 1.55 to 1.75; and a nanoparticulate monolayer or near monolayer associated with the binder layer, the nanoparticulate layer having an effective refractive index less than the refractive index of binder. Methods of making and using the article are also disclosed.

Abstract: A display device comprising a display panel, a diffusing member positioned between the display panel and an observer, and a directional backlight wherein the directional backlight comprises a half angle divergence equal to or less than 15°. The display cover is preferably configured to shift an image displayed on the display panel relative to an observer to obscure a bezel surrounding the display panel. The use of a directional backlight and a diffusing display cover plate allows for a very small gap between the display panel and the display cover plate.

Abstract: An organic light emitting diode comprising a light extraction substructure and a diode superstructure is provided. The light extraction substructure comprises a light expulsion matrix distributed over discrete light extraction waveguide elements and a waveguide surface of the glass substrate. The light expulsion matrix is distributed at varying thicknesses to enhance the planarity of a diode superstructure-engaging side of the light extraction substructure and to provide light expulsion sites at the waveguide element termination points of the discrete light extraction waveguide elements.

Abstract: Methods for modifying multi-mode optical fiber manufacturing processes are disclosed. In one embodiment, a method for modifying a process for manufacturing multi-mode optical fiber includes measuring at least one characteristic of a multi-mode optical fiber. The at least one characteristic is a modal bandwidth or a differential mode delay at one or more wavelengths. The method further includes determining a measured peak wavelength of the multi-mode optical fiber based on the measured characteristic, determining a difference between the target peak wavelength and the measured peak wavelength, and modifying the process for manufacturing multi-mode optical fiber based on the difference between the target peak wavelength and the measured peak wavelength.

Abstract: Methods and apparatus for measuring the modal bandwidth of a multimode optical fiber as a function of wavelength are disclosed. The methods include emitting polarized light from a single-mode fiber, frequency-modulating the single-mode polarized light, and then conditioning the frequency-modulated polarized light to excite multiple modes of the multimode optical fiber. The multimode light transmitted by the multimode optical fiber is detected and analyzed by a network analyzer to determine a bandwidth for at least three different wavelengths. A controller performs a fit to the measured bandwidths using a fitting equation to determine the modal bandwidth as a function of wavelength.

Abstract: Pressure-sensing touch systems and methods are disclosed for sensing the occurrence of a touch event based on pressure applied at a touch location. The touch system includes a light-source system and a detector system operably adjacent respective input and output edges of a waveguide. Pressure at a touch location on the waveguide gives rise to a touch event causes the waveguide to bend or flex. The waveguide bending causes a change in the optical paths of light traveling by FTIR, causing the light distribution in the output light to change. The changes are detected and are used to determine whether a touch event occurred, as well as the time-evolution of the touch event. The changes in the output light can include polarization changes caused by birefringence induced in the waveguide by the applied pressure applied. Various detector configurations are disclosed for sensing the location and pressure of a touch event.

Abstract: Multimode optical fiber is disclosed herein having a core surrounded by first and second annular cladding regions. The second annular cladding region has a maximum relative refractive index that is at least 0.05% higher than the minimum relative refractive index of the first annular cladding region.

Abstract: A system for simultaneously determining strain and temperature characteristics of an object comprising: (i) at least one optical fiber having at least two Brillouin peaks; (ii) at least one connector securing the optical fiber to the object to be monitored; (iii) a laser positioned to provide laser light to said at least one optical fiber; (iv) a device measuring frequencies of said at least two Brillouin peaks, and determining frequency shifts of said at least two Brillouin peaks for said at least one optical fiber along the length of fiber; and (v) a system calculating strain and temperature characteristics along said fiber, based on the coefficients of strain and temperature as well as the measured Brillouin frequency shifts for said optical fiber along the length of said optical fiber.

Abstract: A touch screen system configured to detect a displacement of a cover sheet when pressure or force is applied to the cover sheet upper surface. A light source and photodetector are configured to be in optical communication by reflection of light from the light source from the lower surface of the cover sheet. A displacement of the coversheet changes the amount of reflected light that falls upon the detector. The detector signal can be used to measure the amount of displacement, as well as the time-evolution of the displacement. The touch-screen system can be interfaced with a touch-sensitive display unit to form a display system having both pressure-sensing capability and touch-sensing capability.

Abstract: A few mode optical fiber suitable for use in a mode division multiplexing (MDM) optical transmission system is disclosed. The optical fiber has a graded-index core with a radius R1 in the range from 8 ?m to 14 ?m, an alpha value greater than or equal to about 2.3 and less than about 2.7 at a wavelength of 1550 nm, and a maximum relative refractive index ?1MAX from about 0.3% to about 0.6% relative to the cladding. The optical fiber also has an effective area greater than about 90 ?m2 and less than about 160 ?m2. The core and cladding support only the LP01 and LP11 modes at wavelengths greater than 1500 nm. The cladding has a maximum relative refractive index ?4MAX such that ?1MAX>?4MAX, and the differential group delay between the LP01 and LP11 modes is less than about 0.5 ns/km at a wavelength of 1550 nm.

Abstract: An organic light emitting diode comprising a light extraction substructure and a diode superstructure is provided. The light extraction substructure comprises a light expulsion matrix distributed over discrete light extraction waveguide elements and a waveguide surface of the glass substrate. The light expulsion matrix is distributed at varying thicknesses to enhance the planarity of a diode superstructure-engaging side of the light extraction substructure and to provide light expulsion sites at the waveguide element termination points of the discrete light extraction waveguide elements.

Abstract: A touch system that employs interference effects is disclosed. The touch system includes first and second waveguides that have first and second optical paths that define an optical path difference. The first and second waveguides are configured so that a touch event deforms at least one of the waveguides in a manner that causes the optical path difference to change. The change in the optical path difference is detected by combining the light traveling in the two waveguides to form interfered light. The interfered light is processed to determine the occurrence of a touch event. The time-evolution of the deformation at the touch-event location can also be determined by measuring the interfered light over the duration of the touch event.

Abstract: Curved bezel-concealing display covers and display devices are disclosed. In one embodiment, a bezel-concealing display cover for coupling to a display device having a bezel and a display panel includes a curved perimeter portion having a first surface and a second surface, wherein the curved perimeter portion is configured to be offset from the bezel of the display device by a varying gap GA. The bezel-concealing display cover further includes an array of prisms on at least one of the first surface or the second surface of the curved perimeter portion. The array of prisms extends from an edge of the curved perimeter portion to a distance L. The array of prisms and the curved perimeter portion is configured to shift a portion of an image proximate the bezel produced by the display panel such that the shifted portion of the image appears over the bezel to an observer.