Reviews & Analysis

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.

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.

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.

A breakthrough in metamaterial-based spatial light modulator design makes single-pixel real-time imaging practical by using compressive sensing to dispense with slow mechanical scanning.

Embedding a thin layer of chalcogenide glass inside a polymer paves the way for a new form of flexible optical waveguides and integrated optical circuits.

Photonic crystals have long been used to confine and guide propagating electromagnetic waves with low loss. Now, a new twist has been added by exploiting their leaky mode to effectively trap and dissipate incident electromagnetic energy over a broad frequency band.

Marrying the single-molecule detection ability of surface-enhanced Raman scattering with the extreme time resolution of ultrafast coherent spectroscopy enables the vibrations of a single molecule to be observed.

The report of an electrically pumped polariton laser that operates at room temperature and relies on an inversionless lasing scheme holds promise for realizing a new breed of very low threshold semiconductor lasers.

Rapid developments in perovskite solar cells, photocatalysis and transparent conductors were showcased at the 2014 MRS Spring Meeting.

A two-level system in an optical cavity pumped by an external laser can be coaxed to emit light bursts of exactly N photons at a time.

The ability to control the polarization of short-wavelength radiation generated by high-harmonic generation is useful not only for applications but also for testing conservation laws in physics.

It has been 20 years since near-infrared spectroscopy was first used to investigate human brain function. The technique has subsequently been extended to offer high-resolution imaging of the cortex and has now become a viable alternative to functional magnetic resonance imaging.

Laser systems designed for fusion research are able to produce a high density of X-ray photons in a metal cavity. Scientists have now proposed that this environment could be used to create matter from light and test a fundamental prediction of quantum electrodynamics.

A high energy conversion efficiency and a low fabrication cost are required to make the widespread implementation of solar cells attractive. Researchers are striving to enhance cell performance by developing heterojunction techniques, introducing photonic-crystal structures and proposing new device designs.

The dot-to-dot variation of the optical transition frequency makes it impractical to use single-photon sources based on semiconducting quantum dots in quantum computing, which requires indistinguishable photons. This can now be overcome by using coherently scattered single photons from a dot and tuning them using a microcavity.