Volume 12 Issue 2, February 2018

Volume 12 Issue 2

Breaking symmetry with sound

Photograph of a number of electromechanically pumped optical isolators on an aluminium nitride chip. These magnet-free isolators use sound waves to break time-reversal symmetry for light propagation. The devices are fabricated by electron-beam photolithography and the isolation band for each device can be lithographically defined. The isolators are designed for operation near 1,550 nm with a bandwidth exceeding 1 GHz.

See Sohn et al.

Image: Donggyu Benjamin Sohn, University of Illinois at Urbana-Champaign. Cover Design: Bethany Vukomanovic

Books & Arts

Research Highlights

News & Views

  • News & Views |

    Metasurfaces can in principle provide a versatile platform for optical functionalities, but in practice designing and fabricating them to specifications can be difficult. Now, the realization of metasurfaces with engineered disorder allows for versatile optical components that combine the best features of periodic and random systems.

    • Jacopo Bertolotti
  • News & Views |

    Implementing non-reciprocal elements with a bandwidth comparable to optical frequencies is a challenge in integrated photonics. Now, a phonon pump has been used to achieve optical non-reciprocity over a large bandwidth.

    • Alireza Seif
    •  & Mohammad Hafezi
  • News & Views |

    Irradiating arrays of metal nanowires with intense femtosecond laser pulses produces high-brightness picosecond X-ray pulses. By specifically tailoring the plasma properties, up to 20% conversion efficiency of optical light into X-rays can be achieved.

    • Daniel Rolles
  • News & Views |

    The ability to switch fluorophores on and off is key to performing super-resolution nanoscopy. To date, all switching schemes have been based on an incoherent response to the laser field. Now, a nanoscope that uses on–off coherent switching of quantum dots has been demonstrated.

    • Thomas A. Klar
  • News & Views |

    The study of the complex, unstable dynamics of lasers is not just of scientific value but is also creating new opportunities for making secure lidar and generating high-frequency microwave signals.

    • Oliver Graydon



  • Article |

    Using designer-disordered metasurfaces, optical input–output characteristics, which are typically difficult to obtain, can be known a priori. The approach is used for wavefront shaping, high-numerical-aperture focusing and fluorescence imaging.

    • Mooseok Jang
    • , Yu Horie
    • , Atsushi Shibukawa
    • , Joshua Brake
    • , Yan Liu
    • , Seyedeh Mahsa Kamali
    • , Amir Arbabi
    • , Haowen Ruan
    • , Andrei Faraon
    •  & Changhuei Yang
  • Article |

    Near-infrared organic light-emitting diodes that operate in the 700 nm region with an external quantum efficiency of almost 10% are reported.

    • Dae-Hyeon Kim
    • , Anthony D’Aléo
    • , Xian-Kai Chen
    • , Atula D. S. Sandanayaka
    • , Dandan Yao
    • , Li Zhao
    • , Takeshi Komino
    • , Elena Zaborova
    • , Gabriel Canard
    • , Youichi Tsuchiya
    • , Eunyoung Choi
    • , Jeong Weon Wu
    • , Frédéric Fages
    • , Jean-Luc Brédas
    • , Jean-Charles Ribierre
    •  & Chihaya Adachi
  • Article |

    Using an ultrafast, time-stretched frequency comb laser operating with repetition rates from 7.6 MHz to 18.9 MHz, a rapid and large-volumetric-field optical coherence tomography at an imaging rate of up to 7.5 volumes per second is demonstrated.

    • Meena Siddiqui
    • , Ahhyun S. Nam
    • , Serhat Tozburun
    • , Norman Lippok
    • , Cedric Blatter
    •  & Benjamin J. Vakoc