Volume 15 Issue 3, March 2021

Radiation pressure exerted by light was a lifelong passion for Arthur Ashkin. He foresaw that light pressure could do useful work and invented the optical tweezers that can trap microscopic objects, from small ‘living things’ down to individual atoms.

A new paradigm is emerging in which molecular properties are controlled by modifying the local electromagnetic environment, rather than the traditional approach of changing their composition or structure. Now, a tool to investigate such effects has been demonstrated that should accelerate progress in this exciting field.

Scintillators used in X-ray detectors typically require the use of heavy metal atoms to efficiently harvest ionizing radiation. Now the use of halogens is shown to yield efficient, metal-free organic scintillators.

Two independent studies employing the same narrowband deep-blue emitter, ν-DABNA, but different energy transfer schemes, achieve efficient and stable deep-blue electroluminescence.

This Review covers the milestones for extreme-ultraviolet frequency combs and their applications. A future impact on the construction of nuclear-based optical clocks and multidimensional attosecond photoelectron spectroscopy of solids is remarked.

Organic, metal-free materials that act as efficient X-ray scintillators could bring new opportunities for X-ray imaging.

A spin–orbit coupling effect in photonic graphene made of coupled polaritonic microcavities is experimentally realized, revealing the unique fine structure of the eigenstates around the Dirac points, with the formation of a Dresselhaus-like effective magnetic field that can be mapped to a non-Abelian gauge field.

Real-space mid-infrared nanoimaging reveals vibrational strong coupling between molecules and propagating phonon polaritons in unstructured, thin hexagonal boron nitride layers, which could provide a platform for testing strong coupling and local control of chemical properties.

Pure-blue organic LEDs with narrow emission and improved stability show promise for display applications.

Exciton energy cascade transfer and recycling bring improvements in the efficiency and lifetime of deep-blue organic light-emitting diodes.

By focusing a sub-relativistic infrared laser pulse onto a silica target, a periodic deflection pattern of attosecond electron pulse trains is observed. It reveals these subcycle charge dynamics with a streaking speed of ~60 μrad as⁻¹.

Plasmonics and metamaterials enable ptychographic coherent diffractive imaging with improved reconstructed phase and amplitude. The approach may be particularly useful for imaging of extremely thin or highly transparent objects.

A tetradentate Pd(ii) complex with near unity photoluminescent quantum yield is the basis of bright, long-lifetime organic LEDs.

Heterophase CsPbI₃ perovskite gives rise to bright white phosphor-free LEDs.