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G S Kino - One of the best experts on this subject based on the ideXlab platform.

  • measurement of reduced backscattering noise in laser driven Fiber optic gyroscopes
    Optics Letters, 2010
    Co-Authors: Seth W Lloyd, Michael J. F. Digonnet, Vinayak Dangui, G S Kino
    Abstract:

    We report what we believe to be the first demonstration of a laser-driven Fiber optic gyroscope (FOG) built with an air-core Fiber. Its phase noise is measured to be 130 μrad/√Hz. When the sensing Fiber is replaced with a Conventional Fiber, this figure drops to 12 μrad/√Hz. Comparison between these values suggests that the air-core Fiber gyro is most likely not limited solely by backscattering noise but by reflections at the solid-core/air-core interface. By minimizing additional noise sources and reducing the air-core Fiber loss to its theoretical limit (~0.1 dB/km), we predict that the backscattering noise of the laser-driven air-core FOG will drop below the level of current FOGs. Compared with commercial FOGs, this FOG will exhibit a lower noise, improved thermal and mean-wavelength stability, and reduced magnetic-field sensitivity.

  • modeling of the propagation loss and backscattering in air core photonic bandgap Fibers
    Journal of Lightwave Technology, 2009
    Co-Authors: Vinayak Dangui, Michael J. F. Digonnet, G S Kino
    Abstract:

    We report numerical simulations based on normal coupled mode theory of the fundamental-mode loss and backscattering induced in air-core Fibers by random longitudinal perturbations of the core diameter. To quantitatively explain the measured loss of ~24 dB/km at 1550 nm of air-core Fiber HC-1550-02 from crystal fibre, these simulations predict that the autocorrelation function of the perturbation is close to an exponential and characterized by a ratio D/sigma2 of ~2.36 times 1013 m-1, where D is the characteristic length and sigma the amplitude of the perturbation. This analysis yields a characteristic perturbation length for this Fiber in the range of ~1 to ~30 cm. That this is much shorter than in a Conventional Fiber is consistent with the slower speeds at which air-core Fibers are pulled, which reduces the length of the Fiber perturbations. The same exponential perturbation and D/sigma2 ratio also predict that the backscattering coefficient for the fundamental mode of this Fiber is 1.5 times 10-9 mm-1, which agrees well with a measured value. When applied to a 19-cell air-core Fiber from the same manufacturer (HC19-1550-01) the same perturbation predicts a loss of 4 dB/km, which agrees with the measured range of 1.2 to ~10 dB/km. These independent agreements between modeled and measured loss and backscattering coefficients and the reasonable predicted range of perturbation lengths confirm that core dimension variations are the dominant mechanism behind the loss and backscattering of current air-core Fibers.

  • understanding air core photonic bandgap Fibers analogy to Conventional Fibers
    Journal of Lightwave Technology, 2005
    Co-Authors: Michael J. F. Digonnet, G S Kino
    Abstract:

    It is shown from basic principles that the core modes of an air-core photonic-bandgap Fiber (PBF) exhibit similar qualitative and quantitative behavior as the linearly polarized (LP) modes of an equivalent Conventional Fiber whose step-index profile is entirely determined by the band edges of the PBF. This analogy leads to the concept of effective numerical aperture (NA), which is used to provide an intuitive interpretation of the qualitative behavior of PBF modes. By using this equivalence, several key properties, including the number of modes, their cutoff, effective index, size, and divergence, and the dependence of these quantities on the PBF core and cladding parameters, can be predicted approximately by simulating the LP modes of the equivalent step-index Fiber using standard LP-mode simulators or well-known formula. Besides providing a convenient tool to model the modes of a PBF, this analogy gives new physical insight into the fundamental characteristics of these complex waveguides.

  • phase sensitivity to temperature of the fundamental mode in air guiding photonic bandgap Fibers
    Optics Express, 2005
    Co-Authors: Vinayak Dangui, Michael J. F. Digonnet, G S Kino
    Abstract:

    Because in an air-core photonic-bandgap Fiber the fundamental mode travels mostly in air, as opposed to silica in a Conventional Fiber, the phase of this mode is expected to have a much lower dependence on temperature than in a Conventional Fiber. We confirm with interferometric measurements in air-core Fibers from two manufacturers that their thermal phase sensitivity is indeed ~3 to ~6 times smaller than in an SMF28 Fiber, in agreement with an advanced theoretical model. With straightforward Fiber design changes (thinner jacket and thicker outer cladding), this sensitivity could be further reduced down to ~11 times that of a standard Fiber. This feature is anticipated to have important benefits in Fiber optic systems and sensors, especially in the Fiber optic gyroscope where it translates into a lower Shupe effect and thus a greater long-term stability.

Michael J. F. Digonnet - One of the best experts on this subject based on the ideXlab platform.

  • optimization of the splice loss between photonic bandgap Fibers and Conventional single mode Fibers
    Optics Letters, 2010
    Co-Authors: Kiarash Zamani Aghaie, Michael J. F. Digonnet
    Abstract:

    To understand the loss limitations of a splice between a hollow-core Fiber and a Conventional Fiber, we use a numerical model to calculate the expected coupling loss between the NKT Photonics’ HC-1550-02 Fiber and a single-mode Fiber (SMF) of arbitrary step-index profile. When the SMF parameters are optimized, the splice loss is predicted to be as low as ~0.6 dB. This minimum is believed to be largely due to mode-shape mismatch. These predictions are confirmed experimentally by optimizing the splice loss between this photonic-bandgap Fiber and five SMFs with different mode-field diameters (MFDs) and V numbers. With the SMF-28 Fiber, the measured loss is 1.3dB, in excellent agreement with theory. Using a SMF with parameters close to the optimum values (MFD=7.2μm and V=2.16), this loss was reduced to a new record value of 0.79dB.

  • measurement of reduced backscattering noise in laser driven Fiber optic gyroscopes
    Optics Letters, 2010
    Co-Authors: Seth W Lloyd, Michael J. F. Digonnet, Vinayak Dangui, G S Kino
    Abstract:

    We report what we believe to be the first demonstration of a laser-driven Fiber optic gyroscope (FOG) built with an air-core Fiber. Its phase noise is measured to be 130 μrad/√Hz. When the sensing Fiber is replaced with a Conventional Fiber, this figure drops to 12 μrad/√Hz. Comparison between these values suggests that the air-core Fiber gyro is most likely not limited solely by backscattering noise but by reflections at the solid-core/air-core interface. By minimizing additional noise sources and reducing the air-core Fiber loss to its theoretical limit (~0.1 dB/km), we predict that the backscattering noise of the laser-driven air-core FOG will drop below the level of current FOGs. Compared with commercial FOGs, this FOG will exhibit a lower noise, improved thermal and mean-wavelength stability, and reduced magnetic-field sensitivity.

  • modeling of the propagation loss and backscattering in air core photonic bandgap Fibers
    Journal of Lightwave Technology, 2009
    Co-Authors: Vinayak Dangui, Michael J. F. Digonnet, G S Kino
    Abstract:

    We report numerical simulations based on normal coupled mode theory of the fundamental-mode loss and backscattering induced in air-core Fibers by random longitudinal perturbations of the core diameter. To quantitatively explain the measured loss of ~24 dB/km at 1550 nm of air-core Fiber HC-1550-02 from crystal fibre, these simulations predict that the autocorrelation function of the perturbation is close to an exponential and characterized by a ratio D/sigma2 of ~2.36 times 1013 m-1, where D is the characteristic length and sigma the amplitude of the perturbation. This analysis yields a characteristic perturbation length for this Fiber in the range of ~1 to ~30 cm. That this is much shorter than in a Conventional Fiber is consistent with the slower speeds at which air-core Fibers are pulled, which reduces the length of the Fiber perturbations. The same exponential perturbation and D/sigma2 ratio also predict that the backscattering coefficient for the fundamental mode of this Fiber is 1.5 times 10-9 mm-1, which agrees well with a measured value. When applied to a 19-cell air-core Fiber from the same manufacturer (HC19-1550-01) the same perturbation predicts a loss of 4 dB/km, which agrees with the measured range of 1.2 to ~10 dB/km. These independent agreements between modeled and measured loss and backscattering coefficients and the reasonable predicted range of perturbation lengths confirm that core dimension variations are the dominant mechanism behind the loss and backscattering of current air-core Fibers.

  • Air-core photonic-bandgap Fiber-optic gyroscope
    Journal of Lightwave Technology, 2006
    Co-Authors: Hyang Kyun Kim, Michael J. F. Digonnet, Gordon S. Kino
    Abstract:

    We report the demonstration of the first air-core photonic-bandgap Fiber gyroscope. Because the optical mode in the sensing coil travels largely through air, which has much smaller Kerr, Faraday, and thermal constants than silica, far lower dependencies on power, magnetic field, and temperature fluctuations are predicted. With a 235-m Fiber coil, we observe a minimum detectable rotation rate of ~2.7deg/h and a long-term stability of ~2deg/h, which are consistent with the Rayleigh backscattering coefficient of the Fiber and comparable to that measured with a Conventional Fiber

  • understanding air core photonic bandgap Fibers analogy to Conventional Fibers
    Journal of Lightwave Technology, 2005
    Co-Authors: Michael J. F. Digonnet, G S Kino
    Abstract:

    It is shown from basic principles that the core modes of an air-core photonic-bandgap Fiber (PBF) exhibit similar qualitative and quantitative behavior as the linearly polarized (LP) modes of an equivalent Conventional Fiber whose step-index profile is entirely determined by the band edges of the PBF. This analogy leads to the concept of effective numerical aperture (NA), which is used to provide an intuitive interpretation of the qualitative behavior of PBF modes. By using this equivalence, several key properties, including the number of modes, their cutoff, effective index, size, and divergence, and the dependence of these quantities on the PBF core and cladding parameters, can be predicted approximately by simulating the LP modes of the equivalent step-index Fiber using standard LP-mode simulators or well-known formula. Besides providing a convenient tool to model the modes of a PBF, this analogy gives new physical insight into the fundamental characteristics of these complex waveguides.

P Jeppesen - One of the best experts on this subject based on the ideXlab platform.

Oskar Painter - One of the best experts on this subject based on the ideXlab platform.

  • low loss Fiber accessible plasmon waveguide for planar energy guiding and sensing
    Applied Physics Letters, 2004
    Co-Authors: Stefan A Maier, Paul E. Barclay, Thomas J Johnson, Michelle D Friedman, Oskar Painter
    Abstract:

    A metal nanoparticle plasmon waveguide for electromagnetic energy transport utilizing dispersion engineering to increase lateral energy confinement via a two-dimensional pattern of Au dots on an optically thin Si membrane is described. Using finite-difference time-domain simulations and coupled-mode theory, we show that phase-matched evanescent excitation from Conventional Fiber tapers is possible with efficiencies >90% for realistic geometries. Energy loss in this waveguide is mainly due to material absorption, allowing for 1/e energy decay distances of about 320 µm for excitation at telecommunication frequencies. This concept can be extended to the visible regime and promises applications in optical energy guiding, optical sensing, and switching.

  • a low loss Fiber accessible plasmon photonic crystal waveguide for planar energy guiding and sensing
    arXiv: Optics, 2003
    Co-Authors: Stefan A Maier, Paul E. Barclay, Thomas J Johnson, Michelle D Friedman, Oskar Painter
    Abstract:

    A metal nanoparticle plasmon waveguide for electromagnetic energy transport utilizing dispersion engineering to dramatically increase lateral energy confinement via a two-dimensional pattern of Au dots on an optically thin Si membrane is described. Using finite-difference time-domain simulations and coupled-mode theory, we show that phase-matched evanescent excitation from Conventional Fiber tapers is possible with efficiencies > 90 % for realistic geometries. Energy loss in this waveguide is mainly due to material absorption, allowing for 1/e energy decay distances of about 2 mm for excitation at telecommunication frequencies. This concept can be extended to the visible regime and promises applications in optical energy guiding, optical sensing, and switching.

  • Design of photonic crystal waveguides for evanescent coupling to optical Fiber tapers and integration with high-Q cavities
    Journal of the Optical Society of America B, 2003
    Co-Authors: Paul E. Barclay, Kartik Srinivasan, Oskar Painter
    Abstract:

    We describe a novel scheme based on evanescent guided-wave coupling for optically interfacing between Conventional Fiber-optic and planar photonic crystal devices such as waveguides and resonant cavities. By considering the band structure of bulk photonic crystal slabs, we analyze the k space properties of a linear defect waveguide and establish a set of design rules to ensure efficient evanescent coupling with optical Fiber tapers. These rules are used to design a waveguide in a square-lattice photonic crystal. The coupling efficiency is calculated with a coupled-mode theory incorporating the finite-difference time-domain-calculated uncoupled modes of the Fiber taper and photonic crystal waveguide. On the basis of this coupled-mode theory, 95% power transfer from the Fiber taper to the photonic crystal waveguide is possible over a coupling length of 80 lattice periods and with a bandwidth of 1.5% of the center wavelength. The integration of this waveguide with a photonic crystal defect resonant cavity is also presented, thus showing the usefulness of the combined Fiber taper and photonic crystal waveguide system for efficient, optical Fiber-based probing of optical elements based on planar photonic crystal technologies.

Xueyan Zheng - One of the best experts on this subject based on the ideXlab platform.