Optical Society of America

Conquering LED efficiency droop

WASHINGTON, April 30--Like a coffee enthusiast who struggles to get a buzz from that third cup of morning joe, light-emitting diodes (LEDs) seem to reach a point where more electricity no longer imparts the ...

Apr 30, 2012 5 / 5 (10) 0 | with audio podcast

Redefining time

Atomic clocks based on the oscillations of a cesium atom keep amazingly steady time and also define the precise length of a second. But cesium clocks are no longer the most accurate. That title has been transferred ...

Apr 30, 2012 5 / 5 (7) 41 | with audio podcast