Materials for optics

  • Article |

    High-performance optoelectronic devices that operate in the infrared regime at room temperature exhibit wide-range, active and reversible tunability of the operating wavelengths with black phosphorus.

    • Hyungjin Kim
    • , Shiekh Zia Uddin
    •  & Ali Javey
  • Article |

    Cadmium-free blue quantum dot light-emitting diodes are constructed with a quantum yield of unity, an efficiency at the theoretical limit, high brightness and long operational lifetime.

    • Taehyung Kim
    • , Kwang-Hee Kim
    •  & Eunjoo Jang
  • Article |

    Combining thermal scanning-probe lithography with templating enables the production of high-quality gratings that manipulate light through Fourier-spectrum engineering in ways that are not achievable with conventional gratings.

    • Nolan Lassaline
    • , Raphael Brechbühler
    •  & David J. Norris
  • Article |

    A hexagonal (rather than cubic) alloy of silicon and germanium that has a direct (rather than indirect) bandgap emits light efficiently across a range of wavelengths, enabling electronic and optoelectronic functionalities to be combined on a single chip.

    • Elham M. T. Fadaly
    • , Alain Dijkstra
    •  & Erik P. A. M. Bakkers
  • Letter |

    Organic light-emitting devices containing radical emitters can achieve an efficiency of 27 per cent at deep-red and infrared wavelengths based on the excitation of spin doublets, rather than singlet or triplet states.

    • Xin Ai
    • , Emrys W. Evans
    •  & Feng Li
  • Letter |

    Cooperative quantum effects in superlattices of quantum dots made of caesium lead halide perovskite give rise to superfluorescence, with the individual emitters interacting coherently to give intense bursts of light.

    • Gabriele Rainò
    • , Michael A. Becker
    •  & Thilo Stöferle
  • Letter |

    A scalable thermal drawing process is used to integrate light-emitting and photodetecting diodes into textile-ready polymer fibres, which can be woven into fabrics with possible optical communication and health monitoring applications.

    • Michael Rein
    • , Valentine Dominique Favrod
    •  & Yoel Fink
  • Letter |

    A blend of two organic molecules excited by a simple LED light source can release the stored excitation energy slowly as ‘long persistent luminescence’ over periods of up to an hour.

    • Ryota Kabe
    •  & Chihaya Adachi
  • Letter |

    Light-field-driven control of electrons in a conductor is demonstrated by inducing a current by laser pulses in graphene that is sensitive to the carrier-envelope phase.

    • Takuya Higuchi
    • , Christian Heide
    •  & Peter Hommelhoff
  • Letter |

    The incorporation of large numbers of chemically diverse functional components into microfabricated structures at precise locations is challenging; now the precision placement of DNA origami by directed self-assembly is shown to overcome this problem for the purpose of reliably and controllably coupling molecular emitters to photonic crystal cavities.

    • Ashwin Gopinath
    • , Evan Miyazono
    •  & Paul W. K. Rothemund
  • Letter |

    Visible-frequency hyperbolic metasurfaces defined on single-crystal silver exhibit negative refraction and diffraction-free propagation, as well as strong, dispersion-dependent spin–orbit coupling for propagating surface plasmon polaritons, with device performance greatly exceeding those of previous bulk metamaterial demonstrations.

    • Alexander A. High
    • , Robert C. Devlin
    •  & Hongkun Park
  • Letter |

    A miniature laser is reported that uses two-dimensional tungsten diselenide as the active medium, which is placed on a photonic crystal membrane that acts as the laser cavity; the laser emits visible light, with an ultralow pump threshold.

    • Sanfeng Wu
    • , Sonia Buckley
    •  & Xiaodong Xu
  • Letter |

    The insertion of an insulating layer into a multilayer light-emitting diode (LED) based on quantum dots and produced by depositing the layers from solution increases the performance of the LEDs to levels comparable to those of state-of-the-art organic LEDs produced by vacuum deposition, while retaining the advantages of solution processing.

    • Xingliang Dai
    • , Zhenxing Zhang
    •  & Xiaogang Peng
  • Letter |

    Here stable colour changes induced by solid-state electrical switching of ultrathin films of a germanium–antimony–telluride alloy are demonstrated, adding to its established uses in data storage; possible applications include flexible and transparent displays.

    • Peiman Hosseini
    • , C. David Wright
    •  & Harish Bhaskaran
  • Letter |

    A broadband, compact, all-electrically driven mid-infrared frequency comb based on a quantum cascade laser widens the scope of application of combs in this frequency range beyond that of sources which depend on a chain of optical components.

    • Andreas Hugi
    • , Gustavo Villares
    •  & Jérôme Faist
  • Letter |

    A class of metal-free organic electroluminescent molecules is designed in which both singlet and triplet excitons contribute to light emission, leading to an intrinsic fluorescence efficiency greater than 90 per cent and an external electroluminescence efficiency comparable to that achieved in high-efficiency phosphorescence-based organic light-emitting diodes.

    • Hiroki Uoyama
    • , Kenichi Goushi
    •  & Chihaya Adachi
  • Letter |

    A free-electron laser is used to power a pulsed electron paramagnetic resonance spectrometer at 240 GHz, demonstrating a range of experimental possibilities such as the manipulation of spin-1/2 systems with 6-ns pulses and the measurement of ultrashort decoherence times.

    • S. Takahashi
    • , L.-C. Brunel
    •  & M. S. Sherwin
  • Letter |

    Using an organic molecular crystal as gain medium allows a maser to be operated in pulsed mode in air, at room temperature and in the terrestrial magnetic field, so avoiding many of the obstacles that have previously hindered the application of masers.

    • Mark Oxborrow
    • , Jonathan D. Breeze
    •  & Neil M. Alford
  • Letter |

    Propagating optical plasmons — collective electron excitations coupled to photons — are launched in graphene and studied with near-field optical microscopy, revealing ultra-strong optical field confinement and gate-tunable control of optical fields at nanoscale dimensions.

    • Jianing Chen
    • , Michela Badioli
    •  & Frank H. L. Koppens
  • Brief Communications Arising |

    • Seungchul Kim
    • , Jonghan Jin
    •  & Seung-Woo Kim
  • Letter |

    A new family of resonators for nanoscale lasers is described that allows the size of the laser cavity to be scaled down without increasing the threshold power required to drive lasing.

    • M. Khajavikhan
    • , A. Simic
    •  & Y. Fainman
  • Letter |

    In the area of metamaterials it is shown that electromagnetic properties can be achieved that are not attainable with natural materials. The main research efforts have been directed towards experimentally realizing materials with negative refractive index, but to extend the potential and design flexibility for novel 'transformation optics' applications, it is of considerable interest to produce a material with unnaturally high refractive index. A broadband, flexible terahertz metamaterial with unprecedented high refractive index, reaching a value of 38.6, is now demonstrated.

    • Muhan Choi
    • , Seung Hoon Lee
    •  & Bumki Min
  • Letter |

    A quantum computer based on optical processes requires a source of entangled photons that can be delivered efficiently on demand. Such a source has now been developed: it involves a compact light-emitting diode with an embedded quantum dot that can be driven electrically to generate entangled photon pairs.

    • C. L. Salter
    • , R. M. Stevenson
    •  & A. J. Shields