1. Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
2. Fujikura Ltd., Tokyo, Japan
3. Lumentum, Shinjuku Square Tower 15F, Tokyo, Japan
4. Department of Mechanical Engineering, The University of Tokyo, Tokyo, Japan
5. Canatu, Ltd., Helsinki, Finland
6. Department of Applied Physics, Aalto University School of Science, Aalto, Finland