New light on organic LEDs
Light emission from organic materials occurs through two separate processes: fluorescence – the process by which today’s organic semiconductors produce light – and phosphorescence. I...
Atom opticians think small
Mara Prentiss and colleagues at Harvard University in the US mounted two short wires on a sapphire substrate (Phys. Rev. Lett. 84 1124). When electric currents flow in opposite directions through the ...
Adaptive-optics to cover the sky
Adaptive-optic telescopes differ from normal telescopes by using a thin flexible primary mirror that can easily be deformed. A bright guide star near the observing area acts as a “beacon” ...
Solitons formed in Bose–Einstein condensate
Bose–Einstein condensates are trapped atoms that are cooled to low temperatures and occupy the same quantum state. They are ideal for studying and manipulating quantum effects such as solitons a...
Newton tops PhysicsWeb poll
Almost 400 people took part in the PhysicsWeb poll, each one naming their top-five physicists. The votes for each physicist were added up and weighted according to how they were ranked by individual v...
NASA plans astrometric mission
Like ESA’s recent Hipparcos mission, FAME will use the parallax method to determine the stars’ positions: as the telescope and the Earth orbit the sun, the position of the stars will chang...
Blue lasers look up
Most semiconductor lasers emit light from the edge of the active laser region. However, in the VSCEL geometry light is emitted from the top of the device. This can reduce the threshold current needed ...
New angle for optical memories
The medium is made of nanocrystals of zinc sulphide doped with samarium. Although the nanocrystals are only 3 nanometres long, they clump together into larger particles to form a powder that can be us...
Light feels the heat and slows down
The researchers also showed that the rubidium gas, which they say is a “relatively easily created medium”, exhibits extremely efficient nonlinear interactions. Materials with such properti...
Telescopes on the cheap?
This is not the first time that astronomers have considered using rotating platters of liquid – usually mercury – for a central mirror. For example, a mercury-based telescope would cost on...
