Suitably tailored temporal modulations in coupled photonic crystal cavities can realize non-reciprocal signal transport in a magnet-free nanophotonic platform. In the pictured device, light flows as indicated by the white arrows, thus allowing it to function as an optical circulator, breaking the inherent transmission symmetry of Lorentz reciprocity.

See Sounas and Alù 11, 774–783 (2017)

Quantum optics with X-rays

Artistic impression of the interaction between X-ray photons and nuclear transitions in 57Fe atoms that are located inside coupled cavities. The approach allows quantum effects such as Rabi oscillations to be observed with X-rays rather than with visible or infrared light.

See Haber et al. 11, 720–725 (2017)

Artistic impression of an electronic-plasmonic transducer based on metal–insulator–metal tunnel junctions coupled to a gold plasmonic waveguide. The scheme efficiently directly converts electrical signals into surface plasmon polaritons or vice versa and suits on-chip integration.

See Du et al. 11, 623–627 (2017)

Artist's view of a microcavity filled with a droplet of a dye–polymer solution. Transversally scanning a green laser beam across the droplet forms variable potential landscapes for light trapped in the microcavity and allows the creation of coupled photon Bose–Einstein condensates.

Letter p565

IMAGE: DAVID DUNG, UNIVERSITY OF BONN

COVER DESIGN: BETHANY VUKOMANOVIC

Artist's impression of high-order multiphoton Thomson scattering. Laser light is focused to a billion-times higher brightness than the surface of the Sun and interacts with an electron beam. The resulting figure-of-eight electron-quiver motion generates a high-energy X-ray photon with novel characteristics.

Article p514

IMAGE: WENCHAO YAN, UNIVERSITY OF NEBRASKA—LINCOLN

COVER DESIGN: BETHANY VUKOMANOVIC

Artistic depiction of an array of interconnected Mach–Zehnder interferometers formed from optical waveguides with phase-shifters (pink). These mesh-like patterns can be used to create optical neural networks and programmable photonic processors on a chip.

Articles p441 and p447; News & Views p403

IMAGE: NICHOLAS C. HARRIS, MASSACHUSETTS INSTITUTE OF TECHNOLOGY

COVER DESIGN: BETHANY VUKOMANOVIC

Artistic representation of a graphene–silicon image sensor array consisting of a quantum dot-sensitized graphene layer applied to a silicon CMOS chip with read-out circuitry.

Article p366; News & Views p332

IMAGE: FABIEN VIALLA, ICFO

COVER DESIGN: BETHANY VUKOMANOVIC

Scanning electron microscope image of a one-dimensional InP-based photonic crystal nanolaser diode integrated with silicon photonics. The compact, electrically driven laser emits light at 1.55 μm into an underlying silicon waveguide and operates with a wall-plug efficiency exceeding 10%.

Letter p297

IMAGE: FABRICE RAINERI, UNIV. PARIS DIDEROT

COVER DESIGN: BETHANY VUKOMANOVIC

A superconducting nanowire delay line that acts as a position-resolving single-photon detector. An incident photon results in a microwave signal being sent in both directions down the meandering delay line. The difference in the arrival times of the signal at the two ends of the delay line can then be used to calculate both the position and time of arrival of the original photon.

Article p247

IMAGE: SAMPSON WILCOX, RESEARCH LABORATORY OF ELECTRONICS, MIT

COVER DESIGN: BETHANY VUKOMANOVIC

Artistic depiction of a photonic bound state in the continuum in a structure with a zero-index shell (transparent) and a dielectric core (red). Zero-index structures allow for unconventional wave dynamics such as three-dimensional confinement of electromagnetic fields in an arbitrarily shaped region.

Review Article p149

IMAGE: ELLA MARUSHCHENKO

COVER DESIGN: BETHANY VUKOMANOVIC

Artist's impression of the transmission of topological data bits, formed from polarization domain walls, in an optical fibre.

Article p102

IMAGE: LOIC BRUNOT (INDELEBIL)

COVER DESIGN: BETHANY VUKOMANOVIC

A celebratory cover for the tenth anniversary of the launch of Nature Photonics. The image depicts the diversity of the research published in the journal, including findings related to displays, photonic crystals, optical communications, free-electron lasers, metamaterials and imaging. The images from bottom left to top right are from the covers of the June 2009, January 2008, October 2010, June 2007, April 2007 and February 2016 issues of Nature Photonics.

COVER DESIGN: ALLEN BEATTIE