[1] Fujitsu Limited, Fujitsu Laboratories, Limited, 10-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0197, Japan
[2] Optoelectronic Industry and Technology Development Association (OITDA), 1-20-10 Sekiguchi, Bunkyo-ku, Tokyo 112-0014, Japan
[3] Nanoelectronics Collaborative Research Center (NCRC), Institute of Industrial Science (IIS), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
[4] QD Laser Inc., 1-14-17 Kudankita, Chiyoda-ku, Tokyo 102-0073, Japan
[5] Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan