Volume 6 Issue 9, September 2012

The consortium that brought together laser research institutions from across Europe has been extended for three more years. The geographical expansion of the group, particularly in central and Eastern Europe and scientifically less well-developed countries, paints a picture for photonics in Europe.

A three-dimensional imaging technique that harnesses reflected, coherent X-rays promises the ability to image nanomaterials within substrates.

Scientists have shown that Förster resonance energy transfer can be used to realize new designs of dye laser that offer improved photostability and access to new pumping and emission wavelengths.

The demonstration of edge- and surface-emitting lasers made by transfer-printing epitaxial layers of compound semiconductors onto silicon substrates creates new opportunities for optoelectronics.

The implementation of a quantum Wheeler's delayed-choice experiment defies the conventional boundaries set by the complementarity principle and shows photons coherently oscillating between particle and wave behaviours in a single experimental set-up.

Researchers realize transmission eigenchannels in a disordered medium and demonstrate that a single eigenchannel can transport 3.99 times more energy than uncontrolled waves. This work opens up new avenues for enhancing light-energy delivery to biological tissues and controlling the lasing threshold in random lasers.

Researchers demonstrate coherent X-ray surface scattering imaging in a grazing-incidence geometry that takes advantage of enhanced X-ray surface scattering and interference near total external reflection. Surface patterns are reconstructed in three dimensions with nanometre resolution. The approach has applications in the analysis of buried nano-electronic and nanophotonic structures.

Polymer solar cells are lightweight and may represent a low-cost source of energy, although efficiency still prohibits many practical applications. Here researchers demonstrate polymer solar cells with a certified efficiency of 9.2%. This is achieved by employing an inverted structure that aids photogenerated charge-carrier collection and photon harvesting.

Recent theory predicts that Einstein–Podolsky–Rosen arguments enable an effect in which one party can steer the other but not the converse. Researchers have now demonstrated this one-way steering effect with two entangled Gaussian modes of light, potentially opening up a new field of applications in quantum information.

Researchers experimentally realize the quantum delayed-choice experiment and show that the quantum wave–particle superposition is clearly different from the classical mixture by comparing interference fringes under various conditions. This work reveals the deep relationship between the complementarity principle and the superposition principle of light.

Researchers report the first demonstration of an ultrafast all-optical switch in the single-photon regime. The device, which consists of an InAs/GaAs quantum dot in a photonic crystal defect cavity, exhibits a coherent coupling constant of 141 meV and a quality factor of 25,000. The overall switching time is around 50 ps.

The realization of GaAs lasers on a silicon substrate using a print transfer process offers an alternative wafer-bonding technique for the hybrid integration of optoelectronics.

A hybrid laser that combines silicon photonic-crystal reflectors with transfer-printed InGaAsP quantum wells offers a convenient means of realizing surface-emitting lasers on silicon.

Researchers show that Förster resonance energy transfer between two different dyes makes it possible to realize an efficient and stable laser for applications in biophotonics.

Optical fibres heavily doped with alumina are shown to exhibit an exceptionally low Brillouin gain coefficient and an athermal Brillouin frequency response. Such fibres could prove useful for applications that employ fibre sensing or require high-power fibre laser systems.

Brillouin scattering threatens to limit continued power-scaling for many fibre applications, but sapphire-derived all-glass fibres with large concentrations of alumina may help to eliminate this problem. Nature Photonics spoke to Peter Dragic and John Ballato to learn more.