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Photonics Journal, IEEE This IEEE Publication is an Open Access only journal. Open Access provides unrestricted online access to peer-reviewed journal articles.

Issue 3 • Date Sept. 2009

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Displaying Results 1 - 7 of 7
  • High-Performance Red Lasers With Low Beam Divergence

    Page(s): 172 - 177
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (589 KB) |  | HTML iconHTML  

    We report the design and fabrication of high-performance 650-nm lasers using a novel wafer structure that offers substantially independent control of the vertical far field and of the optical confinement factor. By incorporating a graded V-shaped layer into the epitaxial structure, a low divergence can be realized while retaining high optical overlap with the quantum wells and, therefore, a low threshold current. Broad-area lasers (BALs) were fabricated for a range of designs, and close agreement was obtained between the modeling and the experiment. View full abstract»

    Open Access
  • Flatband Slow Wave in Novel Air-Hole-Array Strip Waveguides

    Page(s): 178 - 183
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (831 KB) |  | HTML iconHTML  

    We design two novel air-hole-array strip waveguides: one with elliptic air holes and the other with sandglass-shaped ones. Simulation results prove that flatband modes with low group velocity and low dispersion can be obtained. Each waveguide has its merits; one can choose waveguides with a low group velocity of 2.52??10-3 c and a narrow bandwidth of 2.71 nm (one with elliptic air holes) or a high group velocity of 1.2??10-2 c and a wide bandwidth of 13.6 nm (one with sandglass-shaped air holes), according to the application. Numerical simulation by finite-difference time domain (FDTD) demonstrates the propagation of the broadband pulse. View full abstract»

    Open Access
  • Nanoholes Grating Couplers for Coupling Between Silicon-on-Insulator Waveguides and Optical Fibers

    Page(s): 184 - 190
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (873 KB) |  | HTML iconHTML  

    Simulation and experimental results of grating couplers composed of arrays of nanoholes are presented. The use of an array of holes instead of a conventional waveguide grating provides an additional degree of freedom in the design of the coupler, thus enabling fabrication using the same photolithography mask and etching process as used for the silicon-on-insulator (SOI) waveguides. A grating coupler with coupling efficiency as high as 34% for coupling between the TE mode of the silicon nanophotonic wire waveguide and a single-mode optical fiber and with 3-dB bandwidth of 40 nm was fabricated. A theoretical model is presented, and 3-D finite-difference time-domain simulations are used to optimize the coupler design. View full abstract»

    Open Access
  • Crosstalk Reduction in Square Cavities

    Page(s): 191 - 196
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1676 KB) |  | HTML iconHTML  

    Theoretically and experimentally, we demonstrate that low crosstalk between two crossed line-defect waveguides formed in a square lattice photonic crystal (PC) structure can be achieved using a resonant cavity at the intersection area. The PC resonator consists of cubic air-holes in silicon air-holes. The Q-factor of the cavity can be changed by increasing the number of holes that form the cavity. The theoretical and experimental crosstalk results are about -40 dB and -20 dB, respectively. View full abstract»

    Open Access
  • Label-Free Biosensing With a Slot-Waveguide-Based Ring Resonator in Silicon on Insulator

    Page(s): 197 - 204
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1158 KB) |  | HTML iconHTML  

    We present a slot-waveguide-based ring resonator in silicon on insulator (SOI) with a footprint of only 13 mum times 10 mum, fabricated with optical lithography. Experiments show that it has 298 nm/RIU sensitivity and a detection limit of 4.2middot10-5 RIU for changes in the refractive index of the top cladding. We prove for the first time that surface chemistry for selective label-free sensing of proteins can be applied inside a 100 nm-wide slot region and demonstrate that the application of a slot waveguide instead of a normal waveguide increases the sensitivity of an SOI ring resonator with a factor 3.5 for the detection of proteins. View full abstract»

    Open Access
  • Soliton Generation and Rogue-Wave-Like Behavior Through Fourth-Order Scalar Modulation Instability

    Page(s): 205 - 212
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1140 KB) |  | HTML iconHTML  

    We numerically study the underlying nonlinear dynamics of ultra-broadband optical wavelength converters based on fourth-order scalar modulation instability. Specifically, we demonstrate the spontaneous emergence of solitons and trapped radiation waves during the frequency conversion process, leading to significant blue and red spectral expansions. Furthermore, we provide a statistical analysis of both Stokes and anti-Stokes bands, showing their intensity histogram evolution as a function of the propagation toward the L-shape signature typical of rogue events. View full abstract»

    Open Access
  • Fast Light and the Speed of Information Transfer in the Presence of Detector Noise

    Page(s): 213 - 224
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (684 KB) |  | HTML iconHTML  

    The phenomenon of fast-light pulse propagation has seen renewed interest in recent years, but its relationship to the speed of information transfer is still being debated. In this paper, we define the speed of information transfer as the propagation speed of a point of constant signal-to-noise ratio (SNR) on the leading edge of a signal pulse. We use standard telecommunication analysis to include the effects of noise so that the bit-error rate (BER) can be calculated as a function of a variable decision time. We introduce the concept of a time-dependent Q-factor so that pulse arrival times can be compared at equivalent BERs. We show that when receiver noise is included in a gain-assisted fast-light system, the measured speed of information transfer can exceed the speed of light for an equivalent pulse travelling through a vacuum. View full abstract»

    Open Access

Aims & Scope

IEEE Photonics is an online-only rapid publication archival journal of top quality research at the fore-front of Photonics.  Photonics integrates quantum electronics and optics to accelerate progress in the generation of novel photon sources and in their utilization in emerging applications at the micro and nano scales spanning from the far-infrared/THz to the x-ray region of the electromagnetic spectrum.

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Meet Our Editors

Editor-in-Chief
Carmen S. Menoni
Colorado State University