Nano- and atom-photonics: Beyond the fundamental limit of light
Motoichi Ohtsu
Interdisciplinary Graduate School of Science and Technology, Tokyo Institute of Technology
4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 2265-8502, Japan
This talk reviews recent progress in nano-photonics and atom-photonics which were proposed by myself several years ago in order to open a new field of optical science and technology beyond the diffraction limit of light. Nano-photonics is defined as a technology that utilizes local electromagnetic interactions between a few nanometric element and an optical near field. Since an optical near field is free from the diffraction of light due to its size-dependent localization and size-dependent resonance features, nano-photonics enables fabrication, operation, and integration of nanometric devices. Thus, this technology can solve the technical problems that are faced by the future optical industry. They are (1) increased integration of photonic devices if the data transmission rates of optical fiber transmission systems are to reach as high as 10Tb/s by the year 2015, (2) sub-100nm width pattern fabrication by photo-lithography for increasing the DRAM capacity by the year 2010, and (3) recording and readout of 25 nm pit pattern for realizing 1 Tb/in2 recording density of the optical memory systems by the year 2010.
The primary advantage of nano-photonics is its capacity to realize novel functions based on local electromagnetic interaction. It should be noted that some of the conventional concepts of wave-optics, such as interference, are no longer essential in nano-photonics. Instead, concepts of surface elementary excitation and nano-fabrication technology are essential.
Novel nano-photonic devices and their integration are proposed and theoretical/experimental studies on their functions are reviewed. Chemical vapor deposition by optical near field is also demonstrated to deposit a variety of nanometric materials on a substrate. A prototype of a high density, high speed optical near field memory system is demonstrated.
Finally, recent progress in our works on atom-photonics, manipulating neutral atoms by optical near field, is reviewed. It can open a new field of atom optics, and can be applied to atomic-scale deposition.
(*) also with ERATO Localized Photon Project, Japan Science and Technology Corporation, 687-1 Tsuruma, Machida-shi, Tokyo 194-0004, Japan