Usually, an elementary light source – such as an excited
atom or molecule – emits light of a particular color at an unpredictable
instance in time. Recently, however, scientists from the MESA+ Institute for
Nanotechnology of the UT, FOM and the Institute for Nanoscience and Cryogenics
(CEA/INAC) in France have shown that a light source can be coaxed to emit light
at a desired moment in time, within an ultrashort burst. The superfast
switching of a light source has applications in fast stroboscopes without laser
speckle, in the precise control of quantum systems and for ultrasecure
communication using quantum cryptography. The theoretical results appeared on
25 September in Optics Express.