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 |

    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
  • 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
  • Research |

    A low-power, fixed microwave signal in combination with an optical-pump signal generates an optical frequency comb that spans the whole wavelength range of the telecommunications C-band, with possible applications ranging from spectroscopy to optical communications.

    • Alfredo Rueda
    • , Florian Sedlmeir
    • , Madhuri Kumari
    • , Gerd Leuchs
    •  & Harald G. L. Schwefel
    Nature 568, 378-381
  • Research | | open

    The mid-infrared spectral region is important for gas sensing applications. Here, Grassani et al. demonstrate efficient supercontinuum generation from fibre-lasers injected into silicon nitride waveguides to provide a turn-key mid-IR source with milliwatt-level output.

    • Davide Grassani
    • , Eirini Tagkoudi
    • , Hairun Guo
    • , Clemens Herkommer
    • , Fan Yang
    • , Tobias J. Kippenberg
    •  & Camille-Sophie Brès

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
  • News and Views |

    A chip-based optical frequency comb source has now been successfully used to send 661 Tbit s–1 over 9.6 km of multicore fibre, bringing considerable savings in the energy consumption and size of data transmission equipment.

    • Daniel J. Blumenthal
    Nature Photonics 12, 447-450