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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


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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
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  • 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
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Amendments & Corrections

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