Category Physics

Image of photonic hypercrystals courtesy of Tal Galfsky

Control of light-matter interaction is central to fundamental phenomena and technologies such as photosynthesis, lasers, LEDs and solar cells. City College of New York researchers have now demonstrated a new class of artificial media called photonic hypercrystals that can control light-matter interaction in unprecedented ways. This could lead to such benefits as ultrafast LEDs for Li-Fi (a wireless technology that transmits high-speed data using visible light communication), enhanced absorption in solar cells and the development of single photon emitters for quantum information processing, said Vinod M. Menon, professor of physics in City College’s Division of Science.

Photonic crystals and metamaterials are two of the most well-known...

1. View into the 2.1-kilometre long accelerator tunnel of European XFEL with the yellow superconducting accelerator modules hanging from the ceiling (photo: DESY/D. Nölle) 2. First Laser Light at the European XFEL, recorded by an X-ray detector at the end of the tunnel. Credit: DESY 3. The undulators gerenate the bright X-ray light. Credit: European XFEL/Heiner Müller-Elsner

European XFEL reaches the last big milestone before the official opening. The 3.4 km long facility, most of which is located in underground tunnels, has generated its first X-ray laser light. The X-ray light has a wavelength of 0.8 nm – about 500 times shorter than that of visible light. At first lasing, the laser had a repetition rate of one pulse per second, which will later increase to 2

7,000 per second.

Europe...

Scientists have developed a new molybdenum-coated catalyst that prevents an unwanted back reaction in certain chemical systems that split water into hydrogen and oxygen. (Andy Freeberg/SLAC National Accelerator Laboratory)

Hydrogen is one of the most promising clean fuels for use in cars, houses and portable generators. But water-splitting systems require a very efficient catalyst. Now an international research team, including scientists at DOE SLAC National Accelerator Laboratory, has developed a new catalyst with a molybdenum coating that prevents this problematic back reaction and works well in realistic operating conditions...

This image illustrates changes in photocurrent before and after exposure to UV light. Persistent photoconductivity is demonstrated even hours after the UV light has been turned off. This is illustrated by the pictograms showing charge carriers that come into contact with cells at the interface during in vitro experiments. Credit: Albena Ivanisevic

Researchers have developed a new approach for manipulating the behavior of cells on semiconductor materials, using light to alter the conductivity of the material itself. Albena Ivanisevic, a professor of materials science and engineering at NC Stat said: “Our work here effectively adds another tool to the toolbox for the development of new bioelectronic devices.” The new approach uses a phenomenon called persistent photoconductivity...