"ENERGY: Photonic thruster pulses into existence"

Photonic thrusters have been imagined by engineers for about 35 years, but a recent demonstration of an experimental spacecraft propulsion system using a laser-based thruster will be described at the American Institute of Aeronautics and Astronautics's annual Space 2007 Conference (Sept. 18, Long Beach, Calif.). NASA funded the successful testing of the photonic laser propulsion (PLP) system earlier this year by the Bae Institute (Tustin, Calif.) Bae claims to have removed the last stumbling block to using photonic thrusters for spacecraft propulsion, by integrating an optical cavity into a laser that traps the beamed photons, thereby amplifying their light pressure by 3000-times.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=201804852