Volume 8 Issue 9, September 2014

Mischaracterization of solar cell power conversion efficiencies and widespread publication of inconsistent data in scientific journals threatens to undermine progress in organic and hybrid photovoltaics research.

The use of carbon nanotubes makes it possible to perform fluorescent imaging of cerebral vasculature of mice through their intact skulls. The high spatial and temporal resolution of the non-invasive technique may prove useful for studies of stroke and other brain disorders.

The fields of metamaterials and plasmonics are both set to benefit from the use of superconducting materials.

In the quest for on-chip optical isolation, scientists demonstrate non-reciprocal optical response based on a 'synthetic' magnetic field in an all-silicon platform. This may open directions to optical routing, on-chip lasers and integrated nanophotonic signal processing.

Developments in optical materials and components for extreme applications such as the James Webb Space Telescope and petawatt laser systems were showcased at CLEO 2014.

This review article summarizes the emerging field of quantum nonlinear optics. Three major approaches to generate optical nonlinearities based on cavity quantum electrodynamics, atomic ensembles with large Kerr nonlinearities and strong atomic interactions are reviewed. Applications of quantum nonlinear optics and many-body physics with strongly interacting photons are also discussed.

A single-shot burst camera has been developed that can generate motion pictures without performing repetitive measurements. It has a frame rate of 4.4 trillion frames per second and a high pixel resolution of 450 × 450 pixels, making it a powerful tool for observing difficult-to-reproduce or non-repetitive events in real time.

An effective magnetic field is generated on a chip and a non-reciprocal phase shift is demonstrated in an 8.35-mm-long interferometer. The magnitude of the non-reciprocal phase produced is comparable to that achievable with monolithically integrated magneto-optical materials.

Some X-ray free-electron laser facilities are pushing towards sub-10 fs pulses, making it desirable to reduce errors in X-ray/optical delay measurements to the 1 fs level. Researchers have now demonstrated X-ray measurements with a temporal resolution shorter than 1 fs, opening up new possibilities for time-resolved X-ray experiments.

A pulsed laser technique that induces mechanical stress in cells offers high-throughput testing of the effect of molecular agents on mechanotransduction in cells.

The use of two, rather than one, donor polymers in an organic solar cell is shown to enhance charge separation, transport and recombination.

Near-infrared photoluminescence from carbon nanotubes makes it possible to optically image the vasculature in the brain directly through the skull.

The phase of a collection of spins is measured with a sensitivity ten times beyond the limit set by the quantum noise of an unentangled ensemble of ⁸⁷Rb atoms. A cavity-enhanced probe of an optical cycling transition is employed to mitigate back-action associated with state-changing transitions induced by the probe.

Femtosecond transient absorption spectroscopy measurements indicate that the dominant relaxation pathway for excited states in perovskite materials is by recombination of free electrons and holes.

A burst-mode camera developed in Japan called STAMP with a femtosecond frame rate could become a powerful tool for studying ultrafast dynamics. Nature Photonics asked Keiichi Nakagawa about the technique.