Frequency combs

Frequency combs are light sources with a spectrum that comprises a series of sharp, equally spaced lines. The frequencies of these lines are known to a very high degree of accuracy, which makes frequency combs an important tool in optical metrology and high-resolution spectroscopy.

Latest Research and Reviews

  • Research | | open

    Frequency combs are useful for precision measurements and to explore atomic and molecular transitions. Here Liu et al. demonstrate photonic chip-based ultraviolet frequency combs of high coherence and broad spectral bandwidth by implementing cubic and quadratic nonlinearities in a non-centrosymmetric material.

    • Xianwen Liu
    • , Alexander W. Bruch
    • , Juanjuan Lu
    • , Zheng Gong
    • , Joshua B. Surya
    • , Liang Zhang
    • , Junxi Wang
    • , Jianchang Yan
    •  & Hong X. Tang
  • Research | | open

    Here, the authors demonstrate full stabilization and control of the two key parameters of a four-wavemixing-based quantum cascade laser comb with metrological precision. These fully-controlled, frequency scalable comb emitters will allow an increasing number of mid- and far-IR applications.

    • Luigi Consolino
    • , Malik Nafa
    • , Francesco Cappelli
    • , Katia Garrasi
    • , Francesco P. Mezzapesa
    • , Lianhe Li
    • , A. Giles Davies
    • , Edmund H. Linfield
    • , Miriam S. Vitiello
    • , Paolo De Natale
    •  & Saverio Bartalini
  • Research |

    The combined technique of dual-comb multi-heterodyne detection and Fourier-transform analysis allows simultaneous acquisition and monitoring of the phase pattern of a generic frequency comb demonstrating the high degree of coherence of the emission of two quantum cascade laser frequency combs.

    • Francesco Cappelli
    • , Luigi Consolino
    • , Giulio Campo
    • , Iacopo Galli
    • , Davide Mazzotti
    • , Annamaria Campa
    • , Mario Siciliani de Cumis
    • , Pablo Cancio Pastor
    • , Roberto Eramo
    • , Markus Rösch
    • , Mattias Beck
    • , Giacomo Scalari
    • , Jérôme Faist
    • , Paolo De Natale
    •  & Saverio Bartalini
  • Research |

    Femtosecond laser pulses can generate self-organized nonlinear gratings in nanophotonic waveguides, providing both quasi-phase-matching and group-velocity matching for second-harmonic generation, and enabling simultaneous χ2 and χ3 nonlinear processes for laser-frequency-comb stabilization.

    • Daniel D. Hickstein
    • , David R. Carlson
    • , Haridas Mundoor
    • , Jacob B. Khurgin
    • , Kartik Srinivasan
    • , Daron Westly
    • , Abijith Kowligy
    • , Ivan I. Smalyukh
    • , Scott A. Diddams
    •  & Scott B. Papp
    Nature Photonics 13, 494-499
  • Research |

    Efficient power transfer from the pump to the soliton can be achieved through field coupling between two optical resonators, allowing soliton frequency comb generation with tens-to-hundreds-of-fold improvement in conversion efficiency compared with a traditional single-resonator comb.

    • Xiaoxiao Xue
    • , Xiaoping Zheng
    •  & Bingkun Zhou
  • Research | | open

    Optical clock networks have many applications from precision time keeping, sensing to fundamental physics. Here the authors demonstrate robust and free-space femtosecond time synchronization of optical clocks via a moving quadcopter.

    • Hugo Bergeron
    • , Laura C. Sinclair
    • , William C. Swann
    • , Isaac Khader
    • , Kevin C. Cossel
    • , Michael Cermak
    • , Jean-Daniel Deschênes
    •  & Nathan R. Newbury

News and Comment

  • Editorial |

    Frequency combs measure optical frequencies with an unprecedented precision, allowing myriad applications in optical metrology, high-precision spectroscopy, optical atomic clocks, attosecond science, astronomy and, recently, quantum information processing.

  • News and Views |

    Microphotonic frequency combs are chip-based light sources, until now confined to optics laboratories. Improved stabilities usher these devices out of the lab and into high-resolution astronomic spectrometer systems.

    • Piotr Roztocki
    •  & Roberto Morandotti
    Nature Astronomy 3, 135-136
  • Research Highlights |

    Two Nature Photonics papers report on microresonator laser frequency combs that enable spectrometer calibration with a precision high enough to potentially spot Earth-like planets in exo-planet searches.

    • Zoe Budrikis
  • News and Views |

    Spatial multiplexing enables the simultaneous generation of several low-noise frequency combs in a single microresonator, promising to enhance a host of applications such as multidimensional coherent spectroscopy.

    • Miro Erkintalo
    Nature Photonics 12, 645-647