The creation of photonic materials, circuitry, devices and probes that act on the nanoscale is yielding new opportunities for controlling light in the sub-wavelength regime. The result could be higher density information storage and processing, and improved sensing and imaging capabilities.

While power generation using silicon solar panels has steadily been increasing over the years, alternative materials that could compete with this technology in terms of efficiency and module costs are intensely being investigated. Yet, to allow for a fair assessment of new photovoltaic technologies, characterization of light-conversion performance should be conducted according to commonly agreed basic rules. This joint web focus collects a series of opinion pieces, recently published in Nature Materials,Nature NanotechnologyandNature Photonics, that discuss the importance of reporting accurate device performance.

Attosecond photonics, currently one of the most promising branches of modern photonics, is progressing at an extremely rapid pace. Although still in its infancy, it has already captured the imagination of the scientific community with its promise of enhancing our understanding of ultrafast phenomena of direct relevance to life, technology and potentially medicine.

The 2014 Nobel Prize in Chemistry was awarded for the development of superresolution fluorescence microscopy, which enables the imaging of fine biological structures previously thought to be unresolvable using light. This collection of news pieces and articles by the Nobel laureates and their collaborators celebrates this achievement.

Thanks to recent developments, lasers based on fibre media with gain are simple, reliable and cost effective. Topics covered in this focus include high-power sources, ultrafast fibre lasers, industry's perspective on the developments in the field over the past decade, applications such as biomedical imaging, and nanotube- and graphene–based saturable absorbers for fibre lasers

This Focus Issue describes the interaction mechanism between terahertz radiation and matter. Topics covered include terahertz sources, on- and off-resonant control using intense terahertz pulses, quantum cascade lasers, superconducting terahertz emitters and terahertz plasmonics.

The issue describes how light interacts with disordered, aperiodic and strongly scattering media to realize a variety of interesting optical phenomena. Topics covered include photonic quasi-crystals, random lasing, Anderson localization and hyper-transport of light as well as potential applications in imaging and next-generation light sources.

Plasmonics takes advantage of the coupling of light to charges like electrons in metals, and allows breaking the diffraction limit for the localization of light into sub-wavelength dimensions enabling strong field enhancements. This Focus Issue covers some of the recent developments in the field including, non-linear plasmonics, acousto-magneto effects, plasmons on graphene and bio-sensor applications.

The mid-infrared spectral region of 2-20 μm contains strong characteristic vibrational transitions of many important molecules as well as two atmospheric transmission windows of 3-5 μm and 8-13 μm, which makes it crucial for applications in spectroscopy, materials processing, chemical and biomolecular sensing, security and industry. This Focus Issue covers recent developments in sophisticated laser technologies such as quantum cascade lasers, fibre lasers and frequency combs, and discusses how plasmonics can be exploited in the mid-infrared regime.

Photovoltaics is expected to provide the next generation of safe, secure, sustainable and affordable energy. The challenges now are to reduce costs and improve power-conversion efficiencies. This Focus Issue covers cutting-edge solar cell technologies such as polymer, dye-sensitized and intermediate-band solar cells, as well as advanced light-harvesting techniques based on plasmonics and quantum dots. Also included is an interview with the world's largest solar-cell manufacturer on the future of the photovoltaic industry.

The fortuitous combination of maturing capabilities, falling component prices and rising demand bodes well for the future of microwave photonics and radio-over- fibre technologies, according to opinions gathered in this month's Technology Focus on the topic.

Although the term 'optofluidics' is less than 10 years old, the combination of light and non-solids is being exploited by researchers who are finding applications in fields ranging from imaging, detection of chemical or biological agents and particle control, through to enhancing photonic circuits and energy generation. The October 2011 issue of Nature Photonicshas a special focus on optofluidics dedicated to some of the latest advances in field.