Commentary

A transistor that operates with photons rather than electrons is often heralded as the next step in information processing, but optical technology must first prove itself to be a viable solution in many different respects.

Recent progress in manipulating quantum states of light and matter brings quantum-enhanced measurements closer to prospective applications. The current challenge is to make quantum metrologic strategies robust against imperfections.

Quantum information protocols based on continuous-variable entangled states are attractive because they exploit standard optical modulation and measurement equipment, and do not require single photons. Recent progress in the field is reversing initial concerns about the practicality of the approach.

The race to demonstrate new lasers, including electrically pumped polymer lasers, makes it a good time to reflect on the measurements that must be undertaken to support a claim of lasing.

The acceleration of charged particles to ultra-high energies by intense laser pulses could be made a reality by petawatt laser facilities. Laser-based approaches promise a low-cost, compact and simple alternative, compared with conventional accelerators.

Super-resolution light microscopy methods either localize single molecular labels or treat the sample as a continuous object. The fundamental requirements for super-resolution in the continuum regime are spatially non-uniform illumination and a nonlinear photoresponse.

Multicolour, three-dimensional stochastic optical reconstruction microscopy now makes it possible to image cellular structures with near molecular-scale resolution.

New optical technologies have revolutionized astronomy, from the invention of the telescope 400 years ago to more recent developments of adaptive optics and segmented mirrors. The next disruptive technologies could well emerge from integrated photonic devices.

More than one-fifth of US electricity is used to power artificial lighting. Light-emitting diodes based on group III/nitride semiconductors are bringing about a revolution in energy-efficient lighting.

While many areas of photonics are being hit hard by the global recession and credit-crunch, others such as solar energy generation and solid-state lighting seem to be continuing to flourish.

Famous for its use in clothing since early times, silk is now finding a new application as a useful biocompatible material in photonic devices. Thin films, diffraction gratings and organic photonic crystals are just a few of the exciting possibilities.

The human eye is a simple, but extremely robust, optical instrument. Analysis by sophisticated wavefront-sensing technology and customized ray-tracing has now revealed that the eye is actually an aplanatic design, with the cornea and lens compensating each other's aberrations.

The Laser Interferometer Gravitational Wave Observatory in the USA is searching for gravitational-wave emissions from cataclysmic astrophysical events. The task has required the construction of the world's largest and most sensitive optical strain sensor.

The extreme speed at which light moves, and the fact that photons do not tend to interact with transparent matter, is of enormous benefit to mankind. It allows us to see deep into the Universe and to transmit data over long distances in optical fibres. So, why slow light down?

Slow-light effects in ultracold atom clouds known as Bose–Einstein condensates offer rich opportunities for storing and processing optical signals.

The spaser is a proposed nanoscale source of optical fields that is being investigated in a number of leading laboratories around the world. If realized, spasers could find a wide range of applications, including nanoscale lithography, probing and microscopy.

Nanophotonics is in its infancy, but a recently published European roadmap is the first attempt to paint a detailed picture of the industry that could emerge in the future.

Biological processes often involve multimolecular interactions on a nanometre scale or at very large molecular concentrations, making them difficult to visualize. Optical antennas have the potential to become powerful tools for nanobioimaging by enhancing optical fields on this tiny scale.

Leading optics researchers gathered together on the Irish south coast to discuss the future direction of photonics in Europe. Their aim was to identify areas of long-term research that have potential strategic importance.

A growing research and development sector is a sign of a healthy economy. South Africa hopes that a focus on photonics technologies will help drive the country's socio–economic development.