43,828 research outputs found

    Photonic Crystal and Photonic Crystal Fibers Communications

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    The development of all optical communications could benefit from the index guiding photonic crystal fibers. In communication the photonic crystal fibers could provide many new solutions. Conventional optical fibers have within the last decades revolutionized the communications industry and it is today a mature technology being pushed to its limit with respect to properties such as losses, single mode operation and dispersion. The spectra have been used by others to develop optical frequency standards. The process can potentially be used for frequency conversion in fiber optic network. In this system the dispersive properties can be controlled by the optical lattice making it possible to achieve phase-matched four wave mixing, like look the process taking place in the photonic crystal fibers. In this paper we will discuss the use of photonic crystal fibers in communications

    Efficient excitation of self-collimated beams and single Bloch modes in planar photonic crystals

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    Using finite-difference time-domain calculations, we investigate out-of-plane coupling between a square-lattice planar photonic crystal and a conventional waveguide located above the photonic crystal. We couple a waveguide oriented in the GX direction to a photonic crystal mode in the second band and show that anticrossing takes place. In this way, a self-collimated beam is launched in the planar photonic crystal, with full power transfer. Furthermore, we investigate the coupling between a waveguide oriented in the GM direction and a photonic crystal and show that single photonic crystal modes can be selectively excited

    Propagation of Light in Photonic Crystal Fibre Devices

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    We describe a semi-analytical approach for three-dimensional analysis of photonic crystal fibre devices. The approach relies on modal transmission-line theory. We offer two examples illustrating the utilization of this approach in photonic crystal fibres: the verification of the coupling action in a photonic crystal fibre coupler and the modal reflectivity in a photonic crystal fibre distributed Bragg reflector.Comment: 15 pages including 7 figures. Accepted for J. Opt. A: Pure Appl. Op

    Continuous-wave operation of electrically pumped, single-mode, edge-emitting photonic crystal Bragg lasers

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    The authors demonstrate an electrically pumped, single-mode, large-area, edge-emitting InGaAsP/InP two dimensional photonic crystal Bragg laser operating in continuous-wave condition. The laser uses a weak index perturbed, polymer-planarized, surface photonic crystal structure to control the optical mode in the wafer plane. They find that the laser operates in single transverse and longitudinal modes. They compare the performance of the photonic crystal Bragg laser with a broad-area laser fabricated from the same wafer and the comparison shows that the performance penalty incurred by the photonic crystal is small

    Graphene-based photonic crystal

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    A novel type of photonic crystal formed by embedding a periodic array of constituent stacks of alternating graphene and dielectric discs into a background dielectric medium is proposed. The photonic band structure and transmittance of such photonic crystal are calculated. The graphene-based photonic crystals can be used effectively as the frequency filters and waveguides for the far infrared region of electromagnetic spectrum. Due to substantial suppression of absorption of low-frequency radiation in doped graphene the damping and skin effect in the photonic crystal are also suppressed. The advantages of the graphene-based photonic crystal are discussed.Comment: 4 pages, 3 figure

    Modal reflectivity in finite-depth two-dimensional photonic-crystal microcavities

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    We present finite-difference time-domain calculations of the Q factor for an optical microcavity defined by a slab waveguide and two-dimensional photonic-crystal end mirrors. The effect of the finite depth of the photonic crystal on the cavity s optical modes is examined. From these calculations, we can optimize the performance of the photonic-crystal mirrors and determine the loss mechanisms within optical cavities defined by these structures. The Q of the cavity modes is shown to be strongly dependent on the depth of the holes defining the photonic crystal, as well as the refractive index of the material surrounding the waveguide core