Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Volume 16 Issue 9, September 2022

Ultrafast upconversion

Artistic impression of a rare-earth-doped upconversion nanoparticle of NaGdF4:Yb3+/Er3+ located in a plasmonic nanocavity formed by a silver nanocube and a silver microsheet. The cavity shortens the luminescence decay time from ~50 μs to sub-50 ns. The result is an enhanced, ultrafast upconversion emission, that is highly directional with applications in nanolasers and quantum optics.

See Chen et al.

Image: Zhenglong Zhang, Shaanxi Normal University. Cover Design: Bethany Vukomanovic


  • Gabriel Popescu passed away in June 2022. He will be remembered as a creative leader in biophotonics, with pioneering contributions to quantitative phase imaging and spectroscopy, an engaging collaborator and a dear friend.

    • Natan T. Shaked
    • YongKeun Park
    • Peter T. C. So




Top of page ⤴

News & Views

  • Multilayered ferroelectric NbOI2 crystals with sub-100-nm thickness exhibit efficient second harmonic generation, paving the way for on-chip nonlinear optical components.

    • Rupert F. Oulton
    • Jefferson Flórez
    • Alex S. Clark
    News & Views
  • The hardest barrier in the way to topological control over light with magnetic fields is extremely weak magneto-optic coupling. Now, strong light-matter coupling in an optical cavity has been used to reach record energy splitting values for photonic spins in magnetic fields. This is a potential game changer for topological photonics.

    • Anton Nalitov
    News & Views
  • The presence of topologically protected edge states is usually determined by angular-resolved photoelectron spectroscopy, requiring clean surfaces and ultrahigh vacuum. Now, an all-optical technique, based on high-harmonic radiation, has been shown to detect topological phase transitions under ambient conditions.

    • Dieter Bauer
    News & Views
  • A new method enables precise control of spin qubits in diamond by selectively activating them with a laser beam, thus paving the way to the control of spin qubits in dense arrays for applications in quantum technology.

    • Tim Hugo Taminiau
    News & Views
  • Optical fibres can now directly generate a variety of Bessel beams thanks to custom-designed, intricate 3D-printed structures applied to their tips.

    • Siddharth Ramachandran
    News & Views
Top of page ⤴


Top of page ⤴


  • Strained NbOI2 flakes with a thickness of 20 nm exhibit a record SHG absolute conversion efficiency of >0.2% and an effective bulk-like nonlinear susceptibility of 1.1 × 10−9 m V−1 at the fundamental wavelength of 1,050 nm. The spatial profile of the polarized second-harmonic generation response can be tuned by the fundamental wavelength.

    • Ibrahim Abdelwahab
    • Benjamin Tilmann
    • Kian Ping Loh
  • Up to six photons in a Greenberger–Horne–Zeilinger state are sequentially generated by using a Rydberg superatom—a mesoscopic atomic ensemble under the condition of strong Rydberg blockade. The efficiency scaling factor for adding one photon is 0.27.

    • Chao-Wei Yang
    • Yong Yu
    • Jian-Wei Pan
  • Microwave-driven holonomic quantum gates on an optically selected electron spin in a nitrogen-vacancy centre in diamond are demonstrated. Optically addressable entanglement is generated between the electron and adjacent nitrogen nuclear spin.

    • Yuhei Sekiguchi
    • Kazuki Matsushita
    • Hideo Kosaka
Top of page ⤴

Amendments & Corrections

Top of page ⤴


Quick links