A research group led by Professor Masataka Nakazawa at Research Institute of Electrical Communication, Tohoku University has successfully achieved ultramulti-level optical transmission using Quadrature Amplitude Modulation (QAM) for the first time. It is the first demonstration of 9-bit of data, or 512 value, transmission at once.

 The conventional optical communication system allows only 1to 2 bit of transmission at once.  In this work, 18-bit information was successfully transmitted at once by combination of 512 QAM and polarization multiplexing.  It means that high-speed optical communications are possible at an extremely low modulation rate, 5% of the conventional speed.
It is expected to contribute to the reduction of the cost and consumption energy of optical communication systems.

More information (Japanese)

[Contact]
Professor Masataka Nakazawa
Research Institute of Electrical Communication, Tohoku University
Address: 2-1-1 Katahira Aoba-ku Sendai, Miyagi, 980-8577, Japan
TEL: +81-22-217-5522, FAX: +81-22-217-5523