Articles in 2009

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  • The generation of random bit sequences at a data rate of up to 300 Gbit s−1 — a rate many orders of magnitude faster than previously achieved — is realized by exploiting the output of a chaotic semiconductor laser. The randomness of the generated bits is verified by standard statistical tests.

    • Ido Kanter
    • Yaara Aviad
    • Michael Rosenbluh
    Article
  • A terahertz wire laser with an unprecedented tuning range of ∼137 GHz has been demonstrated. This scheme relies on bringing dielectric or metallic structures into close proximity with the wire, thus modifying the properties of its guided mode.

    • Qi Qin
    • Benjamin S. Williams
    • Qing Hu
    Article
  • Whispering-gallery-mode resonators made of nematic liquid-crystal droplets offer a wavelength tunability approximately two orders of magnitude larger than that of conventional solid-state microresonators.

    • M. Humar
    • M. Ravnik
    • I. Muševič
    Article
  • A streak camera for characterizing the ultrashort X-ray pulses produced by a free-electron laser is reported. The scheme has a single-shot capability, a resolution of a few femtoseconds and is expected to become a useful tool for X-ray metrology, including experiments involving time-resolved spectroscopy and imaging.

    • Ulrike Frühling
    • Marek Wieland
    • Markus Drescher
    Article
  • All-optical wavelength routing based on optical gradient force in mechanically compliant spoked resonators is demonstrated over a wavelength range that is 3,000 times greater than the resonator linewidth. A switching time of less than 200 ns, a tuning efficiency of 309 GHz mW−1 and 100% channel-quality preservation over the entire tuning range is achieved.

    • Jessie Rosenberg
    • Qiang Lin
    • Oskar Painter
    Article
  • The power-conversion efficiency of dye-sensitized solar cells is increased by 26% by using energy relay dyes. The scheme aids the absorption of high-energy photons that undergo Förster resonant energy transfer to a sensitizing dye, and may offer a viable pathway for developing more efficient dye-sensitized solar cells.

    • Brian E. Hardin
    • Eric T. Hoke
    • Michael D. McGehee
    Article
  • Opto-acoustic imaging of fluorescent proteins deep within living organisms (Drosophila melanogaster and zebrafish) is reported. The approach uses multiple wavelength illumination of the sample to generate ultrasound waves which are then detected and converted into images.

    • Daniel Razansky
    • Martin Distel
    • Vasilis Ntziachristos
    Article
  • Precise control of single-photon states and multiphoton entanglement is demonstrated on-chip. Two- and four-photon entangled states have now been generated in a waveguide circuit and their interference tuned. These results open up adaptive and reconfigurable photonic quantum circuits not just for single photons, but for all quantum states of light.

    • Jonathan C. F. Matthews
    • Alberto Politi
    • Jeremy L. O'Brien
    Article
  • Bright, efficient and low-drive-voltage colloidal quantum-dot LEDs that have a crosslinked-polymer quantum-dot layer, and use a sol–gel titanium oxide layer for electron transport, are reported. Integrating the QD-LEDs with a silicon thin-film transistor backplane results in a QD-LED display.

    • Kyung-Sang Cho
    • Eun Kyung Lee
    • Jong Min Kim
    Article
  • Using two coherent broadband fibre-laser frequency comb sources, a coherent laser ranging system for absolute distance measurements is demonstrated. Its combination of precision, speed and long range may prove particularly useful for space-based sciences.

    • I. Coddington
    • W. C. Swann
    • N. R. Newbury
    Article
  • A polymer solar-cell based on a bulk hetereojunction design with an internal quantum efficiency of over 90% across the visible spectrum (425 nm to 575 nm) is reported. The device exhibits a power-conversion efficiency of 6% under standard air-mass 1.5 global illumination tests.

    • Sung Heum Park
    • Anshuman Roy
    • Alan J. Heeger
    Article
  • By applying a magnetic field to an atomic vapour, it is shown that the large bandwidth of off-resonance slow-light media can be combined with the Faraday effect to realize a high-bandwidth dispersive probe for atomic systems. This will open up the possibility of probing atomic dynamics on a nanosecond timescale.

    • Paul Siddons
    • Nia C. Bell
    • Ifan G. Hughes
    Article
  • Blue light-emitting diodes with a light extraction efficiency of 73% are reported. The InGaN–GaN devices use a photonic-crystal structure for superior optical mode control; their performance has been characterized experimentally and modelled theoretically.

    • Jonathan J. Wierer Jr
    • Aurelien David
    • Mischa M. Megens
    Article
  • Controlling the orientation of the constituent parts of a metamaterial enables the creation of a new family of optical stereoisomer materials that have an electromagnetic response that can be carefully tailored.

    • Na Liu
    • Hui Liu
    • Harald Giessen
    Article
  • The combination of spectrally resolved two-photon microscopy, fluorescent tags and appropriate theory makes it possible to determine the complex size, configuration and spatial distribution of proteins in single living cells. The findings made could lead to ways of tracking the cellular dynamics of individual molecular complexes.

    • Valerica Raicu
    • Michael R. Stoneman
    • Dilano K. Saldin
    Article