Volume 5 Issue 9, September 2011

Volume 5 Issue 9

Scientists theoretically demonstrate that certain types of light beam can pull particles towards the light source.

Letter by Jun Chen et al.

IMAGE: TOM WILSON

Editorial

  • Editorial |

    Duplicate publication dilutes science and we strive to avoid it.

Commentary

  • Commentary |

    Scientists in Japan struggled in the aftermath of a catastrophic earthquake, radiation problems and power cuts. Nevertheless, they have now largely recovered from the desperate situation.

    • Noriaki Horiuchi

Books and Arts

Research Highlights

News and Views

  • News & Views |

    Scientists have theoretically proposed that it is possible to pull objects from a far distance towards a light source in the absence of axial optical gradient forces.

    • Juan José Sáenz
  • News & Views |

    Although two-photon absorption in a semiconductor is typically a very weak effect, the rate of absorption increases dramatically when the two photons have very dissimilar wavelengths, enabling applications such as ultrafast optical sampling and room-temperature mid-infrared detection.

    • Thomas E. Murphy
  • News & Views |

    Going beyond the conventional approach based on the Faraday effect, scientists have now used acoustic modes optically excited in the core of a photonic crystal fibre to realize a reconfigurable all-optical isolator.

    • Zongfu Yu
    •  & Shanhui Fan
  • News & Views |

    Plasmonics has great potential for enabling energy-efficient, highly integrated optical interconnects. Reducing loss and realizing CMOS-compatible active plasmonic devices are two of the main topics on the current agenda.

    • Rachel Won
  • News & Views |

    Are blue and green vertical-cavity surface-emitting lasers operating at room temperature just around the corner? New gallium-nitride-based vertical-cavity surface-emitting lasers are helping to overcome the intrinsic problem of low conductivities of p layers.

    • Hongxing Jiang
    •  & Jingyu Lin

Review

Letters

  • Letter |

    Theoretical analysis suggests that there exists an optical attractive force capable of “pulling” microparticles towards a light source. This backwards force is generated by using interference to optimize the scattering of light in the forwards direction.

    • Jun Chen
    • , Jack Ng
    • , Zhifang Lin
    •  & C. T. Chan
  • Letter |

    Scientists demonstrate a low-cost technique for implementing arbitrarily designed surface morphologies directly into functional zinc oxide films. The researchers achieve conversion efficiencies of 10.1% when applying the films as transparent front electrodes in amorphous silicon solar cells.

    • Corsin Battaglia
    • , Jordi Escarré
    • , Karin Söderström
    • , Mathieu Charrière
    • , Matthieu Despeisse
    • , Franz-Josef Haug
    •  & Christophe Ballif
  • Letter |

    Materials that exhibit strong reflectivity of hard X-rays at normal incidence are sought after for components such as hard-X-ray cavities, beamsplitters and delay lines. Here, researchers experimentally demonstrate hard-X-ray reflectivities of more than 99% from diamond crystals at near-normal incidence.

    • Yuri Shvyd'ko
    • , Stanislav Stoupin
    • , Vladimir Blank
    •  & Sergey Terentyev

Articles

  • Article |

    Researchers demonstrate solution-processed light-emitting diodes based on a quantum-dot emissive layer between an organic hole-transport layer and an electron-transport layer of ZnO nanoparticles. The device achieves a luminance of 68,000 cd m−2 and power efficiencies of up to 8.2 lm W−1.

    • Lei Qian
    • , Ying Zheng
    • , Jiangeng Xue
    •  & Paul H. Holloway
  • Article |

    Scientists experimentally demonstrate a reconfigurable all-optical isolator based on the optical excitation of a gigahertz guided acoustic mode in a micrometre-sized photonic crystal fibre core. The work is expected to benefit advanced optical communications and all-optical signal-processing systems.

    • M. S. Kang
    • , A. Butsch
    •  & P. St. J. Russell
  • Article |

    Researchers show that dispersed functionalized graphene can exhibit broadband nonlinear optical absorption at fluences well below the damage threshold. An optical energy-limiting onset benchmark of 10 mJ cm−2 at a linear transmittance of 70% was obtained for nanosecond visible and near-infrared pulses. The findings shed light on the formation of practical thin films with broadband optical limiting characteristics.

    • Geok-Kieng Lim
    • , Zhi-Li Chen
    • , Jenny Clark
    • , Roland G. S. Goh
    • , Wee-Hao Ng
    • , Hong-Wee Tan
    • , Richard H. Friend
    • , Peter K. H. Ho
    •  & Lay-Lay Chua
  • Article |

    Researchers use extremely non-degenerate photon pairs to achieve two-photon absorption at levels 100-1,000 times that of degenerate two-photon absorption in direct-gap semiconductors. The technique enables the gated detection of sub-bandgap and sub-100-pJ mid-infrared radiation using large-bandgap detectors at room temperature.

    • Dmitry A. Fishman
    • , Claudiu M. Cirloganu
    • , Scott Webster
    • , Lazaro A. Padilha
    • , Morgan Monroe
    • , David J. Hagan
    •  & Eric W. Van Stryland

Interview

  • Interview |

    Optically pulling a particle towards a light source may be counterintuitive, but it is not impossible. Jack Ng tells Nature Photonics how this force can be achieved.

    • Rachel Won