NEC Achieves 150-km-long Single-photon Transmission

NEC claimed a new distance record of 150 km for a single photon transmission -- a feat that might enable secure network communication based on principles of quantum mechanical physics.
The result was achieved through a newly developed quantum cryptography system consisting of optical planar circuits based on Planar Lightwave Circuit (PLC) technology. NEC said quantum cryptography transmissions in optical networks could some day to used metropolitan areas for truly secure communications. http://www.nec.co.jp/press/en/0403/1201.html