ABSTRACT
Recently, a vast number of studies on nanophotonics have been published in the œeld of nanoscale optical measurement and bioimaging with super-resolution (Ohtsu 1998, Maheswari et al. 1999, Hosaka and Saiki 2001, Matsuda et al. 2003) and information processing technologies (Biolatti et al. 2000, Rinaldis et al. 2002, Troiani et al. 2002), owing to the unique characteristics of optical near œeld, which far exceed the technical limitations of conventional optics (Ohtsu et al. 2008). Especially, nanophotonics has shown promise and is expected to be the technology for next-generation nanoscale devices dealing with large amounts of information resources and low energy consumption (Ohtsu et al. 2002). In such devices, optical near œeld plays an important role in nanophotonic device operations, since the optical near œeld is a mixed state between photon and matter excitation, not only breaking the di˜raction limit that is dependent on the wave nature of light, but also utilizing interesting characteristics inherent in nanophotonics, such as unidirectional energy transfer, optical forbidden transition (Kawazoe et al. 2002), and operations based on coherence of nanometric matters (Sangu et al. 2004), which have not been used in conventional optical devices.
