Nanophotonics exploits the local electromagnetic interaction between nanometric matter via an optical near-field. To analyse this interaction, Ohtsu pioneered a quantum optical theory based on the concept of dressed photons. He has devoted his work to establishing this novel theory and creating corresponding applications.

 His essential contribution is not only breaking the diffraction limit of light, but also realising that innovative optical science and technology would be impossible using conventional propagating light. Ohtsu's research in nanophotonics has the potential to revolutionise the telecommunications industry by providing low-power, high-speed, interference-free devices.

"The requirements for advanced communications and improvements in public welfare in the near future necessitate improved information processing and optical telecommunication systems, high-density optical memory, high-resolution displays and optical input-output interfaces," said Professor Motoichi. "To realise these requirements, the development of nanophotonic devices is an essential research area which industry has recently recognised."

Motoichi Ohtsu received his Ph.D. in electronics engineering from the Tokyo Institute of Technology. He is currently Professor in the Department of Electrical Engineering and Information Systems as well as the Director of the Nanophotonics Research Center, both at the Graduate School of Engineering at the University of Tokyo. He has published 420 papers, has presented almost 90 invited papers at international conferences, and is the author, co-author, or editor of more than 50 books.