The Experts below are selected from a list of 8556 Experts worldwide ranked by ideXlab platform
P.st.j. Russell - One of the best experts on this subject based on the ideXlab platform.
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Endlessly single-mode photonic crystal fiber.
Optics letters, 1997Co-Authors: Tim A. Birks, Jonathan C. Knight, P.st.j. RussellAbstract:We made an all-silica optical fiber by embedding a central core in a two-dimensional photonic crystal with a micrometer-spaced Hexagonal Array of air holes. An effective-index model confirms that such a fiber can be single mode for any wavelength. Its useful single-mode range within the transparency window of silica, although wide, is ultimately bounded by a bend-loss edge at short wavelengths as well as at long wavelengths.
Ali Adibi - One of the best experts on this subject based on the ideXlab platform.
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high q micromechanical resonators in a two dimensional phononic crystal slab
Applied Physics Letters, 2009Co-Authors: Saeed Mohammadi, Ali A Eftekhar, William D Hunt, Ali AdibiAbstract:By creating line defects in the structure of a phononic crystal (PC) made by etching a Hexagonal Array of holes in a 15 μm thick slab of silicon, high-Q PC resonators are fabricated using a complimentary-metal-oxide-semiconductor-compatible process. The complete phononic band gap of the PC structure supports resonant modes with quality factors of more than 6000 at frequencies as high as 126 MHz. The confinement of acoustic energy is achieved by using only a few PC layers confining the cavity region. The calculated frequencies of resonance of the structure using finite element method are in a very good agreement with the experimental data. The performance of these PC resonator structures makes them excellent candidates for wireless communication and sensing applications.
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Evidence of large high frequency complete phononic band gaps in silicon phononic crystal plates
Applied Physics Letters, 2008Co-Authors: Saeed Mohammadi, A.a. Eftekhar, Abdelkrim Khelif, W.d. Hunt, Ali AdibiAbstract:We show the evidence of the existence of large complete phononic band gaps (CPBGs) in two-dimensional phononic crystals (PCs) formed by embedding cylindrical air holes in a solid plate (slab). The PC structure is made by etching a Hexagonal Array of air holes through a freestanding plate of silicon. A fabrication process compatible with metal-oxide-semiconductor technology is used on silicon-on-insulator substrate to realize the PC devices. Measuring the transmission of elastic waves through eight layers of the Hexagonal lattice PC in the ΓK direction, more than 30 dB attenuation is observed at a high frequency; i.e., 134 MHz, with a band gap to midgap ratio of 23%. We show that this frequency region matches very well with the expected CPBG found through theoretical calculations.
Rueylin Chern - One of the best experts on this subject based on the ideXlab platform.
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large full band gaps for photonic crystals in two dimensions computed by an inverse method with multigrid acceleration
Physical Review E, 2003Co-Authors: Rueylin Chern, Chiencheng Chang, Chien C Chang, Robert R HwangAbstract:: In this study, two fast and accurate methods of inverse iteration with multigrid acceleration are developed to compute band structures of photonic crystals of general shape. In particular, we report two-dimensional photonic crystals of silicon air with an optimal full band gap of gap-midgap ratio Deltaomega/omega(mid)=0.2421, which is 30% larger than ever reported in the literature. The crystals consist of a Hexagonal Array of circular columns, each connected to its nearest neighbors by slender rectangular rods. A systematic study with respect to the geometric parameters of the photonic crystals was made possible with the present method in drawing a three-dimensional band-gap diagram with reasonable computing time.
Tim A. Birks - One of the best experts on this subject based on the ideXlab platform.
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Endlessly single-mode photonic crystal fiber.
Optics letters, 1997Co-Authors: Tim A. Birks, Jonathan C. Knight, P.st.j. RussellAbstract:We made an all-silica optical fiber by embedding a central core in a two-dimensional photonic crystal with a micrometer-spaced Hexagonal Array of air holes. An effective-index model confirms that such a fiber can be single mode for any wavelength. Its useful single-mode range within the transparency window of silica, although wide, is ultimately bounded by a bend-loss edge at short wavelengths as well as at long wavelengths.
Daniel M Mittleman - One of the best experts on this subject based on the ideXlab platform.
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defect modes in photonic crystal slabs studied using terahertz time domain spectroscopy
Optics Letters, 2004Co-Authors: Zhongping Jian, Jeremy Pearce, Daniel M MittlemanAbstract:We describe broadband coherent transmission studies of two-dimensional photonic crystals consisting of a Hexagonal Array of air holes in a dielectric slab in a planar waveguide. By filling several of the air holes in the photonic crystal slab, we observe the signature of a defect mode within the stop band, in both the amplitude and phase spectra. The experimental results are in reasonable agreement with theoretical calculations using the transfer matrix method.