1. Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577, Japan
2. Institute of Ultra High Frequency Semiconductor Electronics of RAS, Moscow 117105, Russia
3. Center for Photonics and Infrared Engineering, Bauman Moscow State Technical University, Moscow 111005, Russia
4. Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
5. Department of Computer Science and Engineering, University of Aizu, Aizu-Wakamatsu 965-8580, Japan