In cooperation research with Japan Science and Technology Agency (JST), the research group (Tohoku University and JST) successfully demonstrated the experimental observation of optical nonlinearity at the single-photon level in an optical fiber for the first time in the world. They reported very small conditional phase shifts induced by weak coherent pulses that contain one or less than one photon per pulse on average. The technology developed in this research will be a useful tool for not only proof-of-principle experiments of quantum-optical information processing but also further advanced studies of quantum nonlinear phenomena not yet revealed. This research was conducted as a part of research project supported by CREST and achievement was published online in "Nature Photonics" on 25 January, 2009.

Contact:

Professor Edamastu Keiichi

Research Institute of Electrical Communication

Phone: +81 22-217-5070

FAX: +81 22-217-5071

E-mail: eda_AT_riec.tohoku.ac.jp (Replace _AT_ to @)