Nanooptics

Abstract

Nanooptics deals with optical near fields, the electromagnetic fields that mediate the interaction between nanometric particles located in close proximity to each other. The projection-operator method is a theoretical description of how a virtual exciton–polariton is exchanged between these particles, corresponding to the nonresonant interaction. The optical near field mediates this interaction, and is represented by a Yukawa function, which means that the optical near-field energy is localized around the nanometric particles like an electron cloud around an atomic nucleus. Its decay length is proportional to the particle size. This chapter is primarily a review of nanophotonics, a leading branch of nanooptics, which is the technology utilizing the optical near field. The true nature of nanophotonics is to realize qualitative innovation in photonic devices, fabrication, and systems by utilizing novel functions and phenomena caused by optical near-field interactions, which are impossible as long as conventional propagating light is used. As evidence of such qualitative innovation, this chapter describes novel nanophotonic devices, nanophotonic fabrication, nanophotonic systems, and extensions related to science.