Volume 6 Issue 5, May 2012

Scientists have shown that embedding strips of metal in an organic optical resonator allows its emission properties to be tuned while maintaining coherence.

Scientists have demonstrated an efficient process for generating multiple excitons in adjacent silicon nanocrystals from a single high-energy photon. Their findings could prove useful for a wide range of photovoltaic applications.

Using stimulated Brillouin scattering to achieve extremely high optical gain in silicon nanostructures may allow the realization of new integrated chip-scale photonic devices.

The King Abdullah University of Science and Technology was established in Saudi Arabia in 2009. Nature Photonics recently visited the campus to see how things are shaping up.

Scientists have shown that wrinkles and folds can be used to maximize the absorption of low-energy photons by efficiently redirecting them into a thin absorbing film. This inexpensive technique for structuring photonic substrates could be used to increase the efficiency of many organic photovoltaic cells.

Laser-based particle acceleration offers a way to reduce the size of hard-X-ray sources. Scientists have now developed a simple scheme that produces a bright flash of hard X-rays by using a single laser pulse both to generate and to scatter an electron beam.

Scientists gathered at the spring meeting of the Japan Society of Applied Physics to discuss quantum devices based on silicon and diamond, imaging using the X-ray Berry-phase effect and terahertz near-field microscopy.

Scattering of light is usually seen as an impediment to focusing and imaging. This article reviews the recent progress of how strongly scattering media can be used to focus, shape and compress waves by controlling the many degrees of freedom in the incident waves.

By combining high-resolution nonlinear optical microscopy with few-cycle time resolution, scientists show that they are able to probe the spatiotemporal localization of light waves in random dielectric nanostructures. The findings will aid the study of light localization dynamics in a variety of passive and active random media.

Researchers demonstrate single-photon generation by electrical excitation from a single neutral nitrogen–vacancy centre in a p–i–n diamond diode. The photon generation rate at room temperature was 4 × 10⁴ photons s⁻¹ for an injection current of 14 mA. The researchers also investigated the carrier recombination dynamics of the device.

Scientists show that irradiating a double-foil target with intense few-cycle laser pulses can produce single half-cycle 50 as pulses with peak electric fields as high as 10¹³ V m⁻¹ and pulse energies of up to 0.1 mJ. The findings may stimulate new types of attosecond pump–probe experiments.

Scientists demonstrate a Compton-based electromagnetic source based on a laser-plasma accelerator and a plasma mirror. The source generates a broadband spectrum of X-rays and is 10,000 times brighter than Compton X-ray sources based on conventional accelerators.

By illuminating a sample with several uncontrolled random speckles and implementing a blind structured illumination microscopy algorithm, researchers demonstrate that image reconstruction can be achieved without knowing the original illumination pattern, at a resolution two times better than that of conventional wide-field microscopy.

Using a photoluminescence-based carrier multiplication mechanism recently proposed for closely spaced silicon nanocrystals in SiO₂, scientists demonstrate that adjacent nanocrystals are excited directly upon absorption of a single high-energy photon. They also demonstrate efficient carrier multiplication with an onset close to the energy conservation threshold of twice the bandgap energy.

By placing a thin silver grating inside a microcavity comprised of an organic semiconductor and two dielectric mirrors, researchers show that coherent emission can be selectively stimulated between in- and out-of-phase-locked arrays at room temperature. This work demonstrates that incorporating a lossy metal into a cavity does not suppress lasing.

Researchers demonstrate that wrinkles and folds on polymer surfaces can improve the light-harvesting capabilities of solar cells, increasing external quantum efficiencies by up to 600% in the near-infrared. This fabrication method, which employs elastic instabilities of thin, layered materials, may be economical for patterning photonic structures over large areas.

Nature Photonics spoke to Kim Ta Phuoc about an extremely bright and compact X-ray and gamma-ray source that exploits laser plasma acceleration and Compton scattering simultaneously.