Scientists report three-dimensional photonic crystals composed of silk fibroin, thus introducing a new dimension to research at the interface between nanophotonics and biological applications.Letter p818IMAGE: SUNGHWAN KIM et al.COVER DESIGN: TOM WILSON

Graphene plasmonics is an emerging field of research that utilizes the interaction between metallic plasmonic nanostructures and the plasmons intrinsic to graphene. A natural expansion of this idea is the use of plasmons in heterostructures based on graphene and other two-dimensional crystals, which has potential applications in telecommunications, energy harvesting and sensing.Review p749IMAGE: A. N. GRIGORENKO, M. POLINI & K. S. NOVOSELOVCOVER DESIGN: TOM WILSON

By using a single-crystal silicon optical cavity that enables high immunity to length fluctuations, scientists have realized an ultrastable laser with a fractional frequency instability of 1 × 10–16.Article p687News & Views p638IMAGE: BRAD BAXLEY, JILA AND T. KESSLER et al. COVER DESIGN: TOM WILSON

Introducing a quantum device to Wheeler's delayed-choice experiment helps us understand Bohr's principle of complementarity and the nature of photons.Letter p602News & Views p579IMAGE: GUOYAN WANG & JIAN-SHUN TANG et al.COVER DESIGN: TOM WILSON

Placing a graphene sheet on top of a silicon photonic crystal structure enables ultralow-power optical bistability, self-induced regenerative oscillation and coherent four-wave mixing on a chip.Article p554News & Views p502IMAGE: BAROLINI AND GU et al.COVER DESIGN: TOM WILSON

Crystalline microresonators not only support ultrahigh-Q whispering-gallery modes deep in the mid-infrared but also exhibit anomalous dispersion required for achieving efficient and low-noise comb generation.Review p440IMAGE: SCHLIESSER et al.COVER DESIGN: TOM WILSON

The first realization of an echo-enabled harmonic generation free-electron laser (FEL) may help to provide short-wavelength FELs with very high brightness and full coherence.Letter p360Interview p406IMAGE: Zhao et al.COVER DESIGN: TOM WILSON

Gamma-ray radiation can be produced by Compton scattering an intense laser off relativistic electrons that have been accelerated in a laser plasma accelerator.Letter by Ta Phuoc et al.IMAGE: TA PHUOC et al.COVER DESIGN: TOM WILSON

Scientists have realized a fibre laser with radial emission by filling a cylindrical photonic crystal fibre cavity with a microfluidic gain medium.Letter p229News & Views p217IMAGE: STOLYAROV et al.COVER DESIGN: TOM WILSON

High cell efficiencies, low manufacturing costs and efficient energy-storage techniques are all key steps in helping solar power to become the world’s primary source of energy.

Focus on photovoltaics

IMAGE: ISTOCKPHOTO.COM/PETERPHOTO & TOM WILSON

COVER DESIGN: TOM WILSON

A cloud of cold atoms provides gain and distributed feedback for mirrorless parametric oscillation with a conical emission output.

Letter by Alexander Schilke et al.

IMAGE: ALEXANDER SCHILKE et al.

COVER DESIGN: TOM WILSON

Laser-driven spinning vaterite particles can create microfluidic flows for controlling the growth direction of nerve fibres.

Article by Tao Wu et al.

IMAGE: TAO WU et al.

COVER DESIGN: TOM WILSON