1. Institute for Nano Quantum Information Electronics; The University of Tokyo; 4-6-1 Komaba Meguro-ku Tokyo 153 8505 Japan
2. Institute of Industrial Science; The University of Tokyo; 4-6-1 Komaba Meguro-ku Tokyo 153 8505 Japan
3. QD Laser, Inc., Keihin Bldg. 1F; 1-1 Minamiwataridacho, Kawasaki-ku; Kawasaki Kanagawa 210 0855 Japan