Artist's illustration of a new type of transverse force that small dielectric particles, which are located at the interface between air and water, experience on exposure to circularly polarized light. The force originates from the exchange of spin and orbital angular momenta in the optical domain, which is the focus of this issue of Nature Photonics.

Letter p809

IMAGE: ANDRII PSHENYCHNYI

COVER DESIGN: BETHANY VUKOMANOVIC

Artist's impression of a zero-index metamaterial that is composed of an array of silicon pillars embedded in a polymer and sandwiched between two gold films. The structure exhibits a refractive index of zero at a wavelength of 1,570 nm.

Article p738

IMAGE: ERIC MAZUR

COVER DESIGN: ALEX WING

Photograph of a levitated nanodiamond held in an infrared optical trap. The nanodiamond features a nitrogen–vacancy colour centre that is being excited by a green laser beam. Modulation of the optical trap potential controls the mechanical state of the nanodiamond.

Letter p653; News & Views p633

IMAGE: J. ADAM FENSTER/UNIVERSITY OF ROCHESTER

COVER DESIGN: ALEX WING

The cover shows an artistic illustration of light emission from a whispering gallery mode laser resonator inside a living cell. Such lasers have been made by incorporating an oil droplet or polystyrene microsphere treated with a fluorescent dye into a cell. The laser emission from the cell can be arranged to have a unique signature, thus making the scheme suitable for cell labelling and tracking.

Letter p572; News & Views p559

IMAGE: MATJAŽ HUMAR AND SEOK HYUN YUN

COVER DESIGN: ALEX WING

It is a common historical view that coherent light transport in multimode fibres is chaotic and unpredictable. Scientists now demonstrate that the propagation of light, and thus images, can be predicted over a distance of hundreds of millimetres. The findings could have important implications for endoscopy employing multimode fibres.

Article p529

IMAGE: MAIN, TOMAS CIZMAR; MONA LISA, JOHN BARAN/ALAMY

COVER DESIGN: ALEX WING

The Kramers-Kronig relations, which link the real and imaginary parts of a complex function, are routinely applied in optics to model the frequency response of a material's permittivity. An analysis applied to the spatial distribution of permittivity now suggests the existence of a family of materials that can be perfectly non-reflecting. The image shows the time-averaged electric field profile of a dipole emitter embedded within such a material.

Letter p436

IMAGE: SIMON HORSLEY

COVER DESIGN: ALEX WING

The cover image shows the flow of light with two different wavelengths (1,300 nm and 1,550 nm) through a silicon-chip wavelength demultiplexer. The device has been computationally designed using an inverse algorithm that determines the required spatial distribution of its permittivity.

Letter p374; News & Views p353

IMAGE: ALEXANDER Y. PIGGOTT

COVER DESIGN: ALEX WING

Specially engineered two-dimensional photonic crystals can provide a platform to both trap atoms and engineer their interactions, enabling the exploration of new forms of quantum many-body matter.

Article p320; News & Views p285

IMAGE: ALEJANDRO GONZALEZ-TUDELA AND PACO MARTINEZ TOMAS

COVER DESIGN: ALEX WING

A tessellation of a photoacoustic image of a bundle of growing cells that has been genetically modified so as to greatly increase its optoacoustic signature when probed with light.

Article p239; News & Views p216

IMAGE: PAUL BEARD

COVER DESIGN: SAMANTHA WHITHAM/ALEX WING

Scanning electron microscope image of a portion of a centimetre-long spiral silicon nanowire. Inside the nanowire, infrared light strongly couples to microwave sound. The waveguide confines light by total internal reflection and confines sound by impedance mismatch.

Article p199; News & Views p144

IMAGE: LIESBET VAN LANDSCHOOT, RAPHAËL VAN LAER AND AMIN ABBASI, GHENT UNIVERSITY-IMEC

COVER DESIGN: SAMANTHA WHITHAM

A series of in vivo images, captured at different moments in time and at different depths, of the internal parts of moving Drosophila larvae using a new form of fast light-sheet microscopy.

Article p113; News & Views p80

IMAGE: ELIZABETH HILLMAN,

COLUMBIA UNIVERSITY

COVER DESIGN: SAMANTHA WHITHAM

Artistic image of James Clerk Maxwell, the nineteenth-century physicist whose equations unified electricity and magnetism and explained the existence of electromagnetic waves. It is now 150 years since the equations were formulated and to celebrate the anniversary we have compiled several articles on the topic.

Editorial p1; Commentary p2; Interview p5; Review Article p15

IMAGE: © PICTORIAL PRESS LTD/ALAMY

COVER DESIGN: SAMANTHA WHITHAM