Focusing on nanophotonics, which has been proposed by M. Ohtsu in 1993, this volume begins with theories for operation principles of characteristic nanophotonic devices and continues with novel optical near field phenomena for fabricating nanophotonic devices. Further topics include: unique properties of optical near fields and their applications to operating nanophotonic devices; and nanophotonic information and communications systems that can overcome the integration-density limit with ultra-low-power operation as well as unique functionalities. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.