We study on highly efficient optical antennae based on metallic nanostructures, and develop solar cells as well as artificial- photosynthesis systems which evolve oxygen and hydrogen as a result of a photolysis of water.

?Since the probability of light matter coupling process is not so large originally, effective utilization of light in optical devices is needed. We have recently elucidated the possibility of plasmonic nanostructures as an optical antenna for visible and near infrared light and enhancing light matter coupling process. Applications to various fields are expected such as a solar cell enabling light energy conversion with a small amount of substance.

?Furthermore, the photoelectric conversion system employs water molecules as electron sources. To study further detailed mechanism of the light-energy conversion system, we also address ultra-fast spectroscopy and imaging for the purpose of pursuing electron transfer dynamics from optical antenna to semiconductor electrode as an example. We also study on the development of artificial-photosynthesis systems such as plasmon-induced water splitting and ammonia production systems which attract attention as an energy career.