Abstract: Structured beams, Bessel beams, Laguerre Gaussian beams, and focused Gaussian are used as a natural waveguide and its group velocity can be subluminal (slower than the speed of light) as compared to a Gaussian beam in free space. A free space dispersion relation for a Bessel beam, i.e., the dependence of its wavenumber on its angular frequency, is outlined from which the Bessel beam's subliminal group velocity is derived. For reasonable conditions a Bessel light beam has associated parameters that allow slowing near a critical frequency. The application of Bessel beams for a natural optical buffer in free space is presented. Optical transitions and selection rules in materials are altered by structured light carrying orbital angular momentum (OAM). Nano antennas are used to enhance the interactions of structured light.

Abstract: Majorana photons are transmitted through a biological tissue sample to image the tissue. The Majorana photons have a circular polarization, a radial polarization or an azimuthal polarization. The transmitted photons are processed to produce a digital image of the biological tissue sample.

Abstract: Structured beams, Bessel beams, Laguerre Gaussian beams, and focused Gaussian are used as a natural waveguide and its group velocity can be subluminal (slower than the speed of light) as compared to a Gaussian beam in free space. A free space dispersion relation for a Bessel beam, i.e., the dependence of its wavenumber on its angular frequency, is outlined from which the Bessel beam's subliminal group velocity is derived. For reasonable conditions a Bessel light beam has associated parameters that allow slowing near a critical frequency. The application of Bessel beams for a natural optical buffer in free space is presented. Optical transitions and selection rules in materials are altered by structured light carrying orbital angular momentum (OAM). Nano antennas are used to enhance the interactions of structured light.

Abstract: Structured beams, Bessel beams Laguerre beams, and focused Gaussian are used as a natural waveguide and its group velocity can be subluminal (slower than the speed of light) as compared to a Gaussian beam in free space. A free space dispersion relation for a Bessel beam, i.e., the dependence of its wavenumber on its angular frequency, is outlined from which the Bessel beam's subliminal group velocity is derived. For reasonable conditions a Bessel light beam has associated parameters that allow slowing near a critical frequency. The application of Bessel beams for a natural optical buffer in free space is presented. Optical transitions and selection rules in materials are altered by structured light carrying orbital angular momentum (OAM). Nano antennas are used to enhance the interactions of structured light.

Abstract: A feature management system and method of managing access to API functionality. One embodiment of the feature management system includes: (1) a driver configured to carry out functions, including a restricted function, in response to calls thereto, (2) a memory configured to store a management action associated with the restricted function and (3) a feature manager operable to recognize the call to the restricted function and to retrieve the management action from the memory and direct the driver to carry out the management action in addition to the restricted function.

Abstract: Optical fiber having a coating surrounding and in direct contact with the silica based cladding region of the fiber, the coating having a Young's modulus of elasticity greater than 30 MPa. The optical fiber has low bend losses, especially low microbend induced losses. The optical fiber has a core surrounded by a cladding, and the cladding has a ring portion that includes holes or doped silica or both.

Abstract: An optical fiber comprising: (i) a silica based passive core having a first index of refraction n1; (ii) a silica based cladding surrounding the core and having a second index of refraction n2, such that n1>n2, said cladding having at least one stress rod and at least one air hole extending longitudinally through the length of said optical fiber; and (iii) wherein said optical fiber supports a single polarization mode or poses polarization maintaining properties within the operating wavelength range.

Abstract: An optical fiber including: (i) a silica based, rare earth doped core having a first index of refraction n1; and (ii) at least one silica based cladding surrounding the core and having a second index of refraction n2, such that n1>n2, said cladding having a plurality of stress rods and a plurality of air holes extending longitudinally through the length of said optical fiber; wherein said optical fiber supports a single polarization mode or poses-polarization maintaining properties within the operating wavelength range.

Abstract: A method for measuring fundamental mode cutoff wavelength of single polarization fiber comprising: (i) launching pulsed light of at least one wavelength ?i into one end of the single polarization fiber; (ii) measuring backscattered light intensity corresponding to said wavelength to obtain the backscattered light intensity as a function of fiber position, wherein the backscattered light propagates through the same end of the fiber; and (iii) determining at least one cutoff wavelength and the corresponding position within said fiber for the cutoff wavelength, based on a specified threshold light intensity level.

Abstract: An optical fiber comprising a core having a refractive index profile and a centerline; and a cladding layer surrounding and directly adjacent the core; wherein core includes updoping material and is doped with Aluminum in at least one region of the core, such that either: (a) the average longitudinal acoustic wave velocity within the core is within 0.05% of the longitudinal acoustic wave velocity within the cladding; or (b) the longitudinal acoustic wave velocity in the core changes by at least 0.2%.

Abstract: The present invention provides devices and methods for dispersion compensation. According to one embodiment of the invention, a dispersion compensating device includes a negative dispersion fiber having an input configured to receive the optical signal, the negative dispersion fiber having a length and dispersion sufficient to remove any positive chirp from each wavelength channel of the optical signal, thereby outputting a negatively chirped optical signal; an amplifying device configured to amplify the negatively chirped optical signal; and a nonlinear positive dispersion fiber configured to receive the negatively chirped optical signal. The devices of the present invention provide broadband compensation for a systems having a wide range of variable residual dispersions.

Abstract: A polarization dependent isolator includes a Faraday element, a linear polarizer positioned at a first end of the Faraday element to polarize light entering the first end of the Faraday element, and a single polarization fiber positioned at a second end of the Faraday element to receive light emerging from the second end of the Faraday element. A laser module includes a semiconductor laser diode, a Faraday element positioned adjacent the semiconductor laser diode, a linear polarizer positioned at a first end of the Faraday element nearest to the semiconductor laser diode to polarizer light passing from the laser diode to the first end of the Faraday element, and a single polarization fiber positioned at a second end of the Faraday element furthest from the semiconductor laser diode to receive light emerging from the second end of the Faraday element, wherein the single polarization fiber also serves as coupling output fiber for the laser module.

Abstract: An optical fiber including: (i) a silica based, rare earth doped core having a first index of refraction n1; (ii) a silica based inner cladding surrounding the core and having a second index of refraction n2, such that n1>n2, said inner cladding having a plurality of air holes extending longitudinally through the length of said optical fiber; (iii) a silica based outer cladding surrounding said inner cladding and having a third index of refraction n3, such that n2>n3, wherein said optical fiber supports a single polarization mode within the operating wavelength range.

Abstract: An optical fiber, comprising: (i) a rare earth doped silica based elongated core with a first refractive index (n1) with an aspect ratio of 1:5 to 1; (ii) a silica based moat abutting and at least substantially surrounding the core, the moat having a refractive index n2, wherein n2<n1; (iii) a silica based inner cladding surrounding the moat, the inner cladding having a third refractive index (n3), wherein n1>n3; and n3>n2; (iv) a silica based outer cladding surrounding said inner cladding, the outer cladding having a fourth refractive index (n4), such that n4<n3; the optical fiber exhibits single polarization at the operating wavelength band.

Abstract: An optical fiber, comprising: a central core having a maximum dimension (A) greater than a minimum dimension (B) and a substantially elliptical shape, the fiber having at least one air hole positioned each opposite side of the central core wherein the optical fiber exhibits (i) single polarization propagation within a single polarization band and (ii) polarization maintaining property, such that the fiber beat length normalized at 1550 nm is less than 10 mm; and the polarization maintaining band is situated within wavelengths which are (a) adjacent to and below the single polarization band; and (b) above the higher order mode cutoff wavelength.

Abstract: According to the present invention the optical fiber includes a core with a first refractive index (n1) and the innermost core region with the refractive index n0, a cladding surrounding the core, the cladding having a third refractive index (n3), wherein n1>n3 and n0<n1. According to some of the embodiments the optical fiber may also include a moat surrounding and abutting the core and situated between the core and the cladding, the moat having a second refractive index (n2), wherein n3>n2. It is preferable that at least one of the core, innermost core region and/or moat has a non-circular shape.

Abstract: Disclosed is an optical fiber (20) having a centermost laterally-elongated core (30) having a short dimension (a), a long dimension (b) and a first refractive index (n1), a moat (40) surrounding the central laterally-elongated core, the moat (40) having a second refractive index (n2), an outer dimension (c) and an outer dimension (d), and a cladding (50) surrounding the moat (40), the cladding (50) having a third refractive index (n3), wherein n1>n3>n2, a ratio of b/a is between 1.5 and 5.0, and a ratio of d/a is between 2.0 and 7.0. The fiber exhibits polarization maintaining properties in a PMB situated below (i.e., at shorter wavelength than SPB), such that beat length normalized to 1550 nm wavelength is preferably less than 10 mm. The fiber (20) may be coupled to optical components in apparatus where single polarization or polarization maintaining properties are desired.

Abstract: A dispersion correction optical fiber includes a segmented core having a central core segment, a moat segment and, preferably, a ring segment. The refractive index profile is selected to provide a total dispersion minimum which is located within an operating wavelength band of the fiber. Most preferably, the dispersion value at the minimum is more negative than ?400 ps/nm/km and greater than ?1200 ps/nm/km at 1550 nm. Optical transmission systems including the present invention dispersion correction optical fiber optically coupled to various transmission fibers and dispersion compensating fibers are also disclosed, as is a method of operating the dispersion correction fiber wherein the minimum is located within the desired operating wavelength band.

Abstract: A fuel tank filler neck has a plate that pivots between a position restricting the filler neck and a position permitting introduction of fuel through the filler neck. A vent housing secured on the filler neck has a vapor inlet fitting and a vapor outlet fitting connected through a vent orifice, a pressure relief orifice, and a vacuum relief orifice. A diaphragm vent valve controls flow through the vent orifice. An actuating arm pivoted with the restrictor plate engages the vent valve across the vent orifice when the restrictor plate restricts the filler neck, and permits the vent valve to allow vapor flow from the vapor inlet fitting through the vent orifice to the vapor outlet fitting when the restrictor plate permits introduction of fuel through the filler neck. A diaphragm valve controls flow through the pressure relief orifice, and an umbrella valve controls flow through the vacuum relief orifice.

Abstract: A fuel rail assembly supports injectors for delivering fuel to an engine and includes a pressure regulator to establish the pressure of the fuel supplied to the injectors. The fuel rail body and the pressure regulator base are fabricated from sheet metal, and the pressure regulator base is secured directly to the fuel rail body.