Applied optics

  • Article |

    Engineering of the coupling between optical modes in a lithium niobate chip enables the realization of tunable, bi-directional and low-loss electro-optic frequency shifters controlled using only continuous and single-tone microwaves.

    • Yaowen Hu
    • , Mengjie Yu
    •  & Marko Lončar
  • Article |

    A reinforcement learning experiment using a programmable integrated nanophotonic processor shows that a quantum communication channel with the environment speeds up the learning process of an agent.

    • V. Saggio
    • , B. E. Asenbeck
    •  & P. Walther
  • Article |

    An improved device design for perovskite-based photovoltaic cells enables a certified power conversion efficiency of 25.2 per cent, translating to 80.5 per cent of the thermodynamic limit for its bandgap, which approaches those achieved by silicon solar cells.

    • Jason J. Yoo
    • , Gabkyung Seo
    •  & Jangwon Seo
  • Article |

    A compact, high-performance silicon photonics-based light detection and ranging system for three-dimensional imaging is developed that should be amenable to low-cost mass manufacturing

    • Christopher Rogers
    • , Alexander Y. Piggott
    •  & Remus Nicolaescu
  • Article |

    A surface-electrode ion-trap chip is demonstrated, which delivers all the wavelengths of light required for the preparation and operation of ion qubits.

    • R. J. Niffenegger
    • , J. Stuart
    •  & J. Chiaverini
  • Review Article |

    The current state of programmable photonic integrated circuits is discussed, including recent developments in their building blocks, circuit architectures, electronic control and programming strategies, as well as different application spaces.

    • Wim Bogaerts
    • , Daniel Pérez
    •  & Andrea Melloni
  • Article |

    An air gap embedded within the structure of a thermophotovoltaic device acts as a near-perfect reflector of low-energy photons, resulting in their recovery and recycling by the thermal source, enabling excellent power-conversion efficiency.

    • Dejiu Fan
    • , Tobias Burger
    •  & Stephen R. Forrest
  • Article |

    By monolithically integrating piezoelectric actuators on ultralow-loss photonic circuits, soliton microcombs—a spectrum of sharp lines over a range of optical frequencies—can be modulated at high speeds with megahertz bandwidths.

    • Junqiu Liu
    • , Hao Tian
    •  & Tobias J. Kippenberg
  • 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 turnkey regime for soliton microcombs is demonstrated, in which solitons are generated by switching on a co-integrated pump laser, eliminating the need for photonic and electronic control circuitry.

    • Boqiang Shen
    • , Lin Chang
    •  & John E. Bowers
  • Article |

    A massively parallel coherent light detection and ranging (lidar) scheme using a soliton microcomb—a light source that emits a wide spectrum of sharp lines with equally spaced frequencies—is described.

    • Johann Riemensberger
    • , Anton Lukashchuk
    •  & Tobias J. Kippenberg
  • Article |

    A two-dimensional semiconductor photodiode array senses and processes optical images simultaneously without latency, and is trained to classify and encode images with high throughput, acting as an artificial neural network.

    • Lukas Mennel
    • , Joanna Symonowicz
    •  & Thomas Mueller
  • Article |

    precisely controllable integrated optical gyroscope based on stimulated Brillouin scattering is used to study non-Hermitian physics, revealing a four-fold enhancement of the Sagnac scale factor near exceptional points.

    • Yu-Hung Lai
    • , Yu-Kun Lu
    •  & Kerry Vahala
  • Letter |

    Room-temperature modulation frequencies exceeding 200 GHz are demonstrated in birefringent semiconductor spin-lasers by coupling the spin of the charge carriers to the light polarization.

    • Markus Lindemann
    • , Gaofeng Xu
    •  & Nils C. Gerhardt
  • Letter |

    Contrary to current expectation, eavesdropping on terahertz wireless data links is shown to be easier than expected, by placing an object in the path of the signal that scatters part of it to a receiver located elsewhere.

    • Jianjun Ma
    • , Rabi Shrestha
    •  & Daniel M. Mittleman
  • Letter |

    An optical-frequency synthesizer based on stabilized frequency combs has been developed utilizing chip-scale devices as key components, in a move towards using integrated photonics technology for ultrafast science and metrology.

    • Daryl T. Spencer
    • , Tara Drake
    •  & Scott B. Papp
  • Letter |

    Ohmic losses in plasmonic devices can be reduced by exploiting ‘resonant switching’, in which light couples to surface plasmon polaritons only when in resonance and bypasses them otherwise.

    • Christian Haffner
    • , Daniel Chelladurai
    •  & Juerg Leuthold
  • Letter |

    Photophoretic optical trapping of cellulose particles and persistence of vision are used to produce real-space volumetric images that can be viewed from all angles, in geometries unachievable by holograms and light-field technologies.

    • D. E. Smalley
    • , E. Nygaard
    •  & J. Peatross
  • Letter |

    Ablation cooling is demonstrated as an effective means of removing material using successive bursts of laser pulses with short intraburst delay times; the technique allows the overall pulse energy to be decreased, overcoming negative thermal effects during the ablation process.

    • Can Kerse
    • , Hamit Kalaycıoğlu
    •  & Fatih Ömer Ilday
  • Letter |

    An electronic–photonic microprocessor chip manufactured using a conventional microelectronics foundry process is demonstrated; the chip contains 70 million transistors and 850 photonic components and directly uses light to communicate to other chips.

    • Chen Sun
    • , Mark T. Wade
    •  & Vladimir M. Stojanović
  • Letter |

    Inorganic–organic lead halide perovskite could be efficient when used as the light-harvesting component of solar cells; here incorporation of methylammonium lead bromide into formamidinium lead iodide stabilizes the perovskite and improves the power conversion efficiency of the solar cell up to 17.9 per cent.

    • Nam Joong Jeon
    • , Jun Hong Noh
    •  & Sang Il Seok
  • Letter |

    The next generation of radar systems must be photonic to obtain frequency flexibility and improved performance; here both generation and detection of radio signals are demonstrated in a successful field trial of a photonic-based radar system using aeroplanes.

    • Paolo Ghelfi
    • , Francesco Laghezza
    •  & Antonella Bogoni
  • Letter |

    The resonant interaction between γ-ray photons and an ensemble of nuclei with a periodically modulated resonant transition frequency can be used to control the waveforms of the photons coherently; for example, individual γ-ray photons can be converted into a coherent, ultrashort pulse train or into a double pulse.

    • Farit Vagizov
    • , Vladimir Antonov
    •  & Olga Kocharovskaya
  • Letter |

    Most known ferroelectric photovoltaic materials have very wide electronic bandgaps (that is, they absorb only high-energy photons) but here a family of perovskite oxides is described that have tunable bandgaps, allowing their use across the whole visible-light spectrum.

    • Ilya Grinberg
    • , D. Vincent West
    •  & Andrew M. Rappe
  • Letter |

    The use of organometal halide perovskites as the light-absorbing material in nanostructured solar cells has increased efficiency to practical levels; here it is shown that vapour deposition of the perovskite removes the need for complex nanostructures and will hence simplify large-scale manufacture.

    • Mingzhen Liu
    • , Michael B. Johnston
    •  & Henry J. Snaith
  • Letter |

    An experimental demonstration of the concept of a ‘quantum access network’ based on simple and cost-effective telecommunication technologies yields a viable method for realizing multi-user quantum key distribution networks with efficient use of resources.

    • Bernd Fröhlich
    • , James F. Dynes
    •  & Andrew J. Shields
  • Letter |

    A method of producing perovskite-sensitized solar cells by sequential — as opposed to single-step — deposition of the perovskite’s components onto a nanoporous titanium oxide film allows for greater reproducibility of device performance and a record power conversion efficiency of 15 per cent.

    • Julian Burschka
    • , Norman Pellet
    •  & Michael Grätzel
  • Article |

    Realizing holographic video displays is proving far from straightforward, but it is shown here that it may be possible to overcome the limitations of present displays by harnessing the desirable optical manipulation properties of anisotropic leaky-mode spatial light modulators.

    • D. E. Smalley
    • , Q. Y. J. Smithwick
    •  & S. Jolly
  • Letter |

    The ‘time cloak’ experiment is extended here using a time analogue of the Talbot effect in optics — in which a plane wave incident on a diffraction grating produces repeated images of the grating at regular distances — to show that almost half of the time axis can be concealed.

    • Joseph M. Lukens
    • , Daniel E. Leaird
    •  & Andrew M. Weiner
  • 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 |

    Two gold nanostructures with controllable subnanometre separation are used to follow the evolution of plasmonic modes; the distance at which quantum tunnelling sets in is determined, and a quantum limit for plasmonic field confinement is estimated.

    • Kevin J. Savage
    • , Matthew M. Hawkeye
    •  & Jeremy J. Baumberg