Photonic crystals, in which the refractive index changes periodically, provide a promising new tool for the manipulation of photons and have received keen interest from variety of field. In this manuscripts, I review the recent progress and future prospects of photonic crystals and their applications to photonic nanostructure devices.

Leaky photonic bands are investigated with emphasis placed on the research history of the theoretical treatment of the leakage of photonic-bands photons from photonic crystals. It is stressed that the photon leakage plays a decisive role in various optical processes, such as Raman scattering, light transmission and reflection, and near-field optics, by governing the sharpness of the resonant features arising from the photonic band excitation.

In recent years, the progress in photonic crystal research has been remarkable, and many applications to optoelectronic devices have been proposed and investigated. However, the advantages of photonic crystals compared with those of conventional devices have not yet been fully discussed. In this report, I discuss this matter, showing the recent theoretical and experimental studies on two-dimensional photonic crystals based on semiconductor nanostructures.

Recently, a phenomenon called “negative refraction” has attracted many researchers in various fields. In this article, I review this topic, mainly concerning photonic crystals, and clarify how it works and how it appears. In addition, negative refraction in left-handed metamaterials and negative group velocity in the vicinity of strong resonance lines are discussed, particularly their relationship to negative refraction in photonic crystals. In all cases, negative refraction leads to various exotic light propagation phenomena that seem to contradict our commonsense, but they do not contradict any physical law. These phenomena reflect the uniqueness of light propagation in strongly dispersive media, which had previously been hardly accessible in conventional situations.

The autocloning process is a key technology for producing photonic crystals with high reproducibility and high productivity. After the formation of a periodic corrugation pattern on the substrate, two kinds of dielectric film are stacked alternately on a substrate by an appropriate combination of sputter deposition and sputter etching. The technology offers a means of placing accurately designed optical materials at desired places, and therefore, the process is useful for producing integrated functional components in almost every branch of optics. In this paper, we offer a picture of the technology including features of the process and several applications in various optics industries such as telecommunication and nontelcom.

Techniques of controlling a two-dimensional photonic crystal (2DPC) structure are reviewed, focusing on the precise nanofabrication of air-hole lattices and functional waveguide design in light of application to an ultrasmall and ultrafast symmetric Mach-Zehnder-type all-optical switch (PC-SMZ). In a typical GaAs-based air-bridge- type 2DPC structure, transmission spectra in good agreement with the calculated result　and low propagation loss of less than 1 dB/mm are reproducibly exhibited, while directional couplers with arbitrary and wavelength-dependent coupling strengths play important roles as practical beam splitters/couplers. Through the recent switching operation of the PC-SMZ, the possibility of far advancement of 2DPC-based integrated circuits is concluded.

Nanographene is defined as a carbon-based nanosized flat π-electron system having open edges, which is contrasted to closed π-electron systems of fullerenes and carbon nanotubes. An arbitrarily shaped nanographene can be described in terms of a combination of zigzag and armchair edges. The zigzag edges of nanographene exhibit a nonbonding π-electron state (edge state) of edge origin, which contributes to the production of unconventional nanomagnetism. In the disordered network of nanographite domains, the spin-glass state is stabilized. The magnetic switching phenomenon of edge state spins is observed in the water adsorption process in the nanographite network. In this article, the preparation and structure of nanographene are also reviewed in addition to the anomalous electronic and magnetic properties of nanographene and nanographite.

The progress in optical microscopy has made it possible to observe the behavior of single biomolecules in real time, and even to quantitatively measure the movement of an order of nm and the force generation of an order of pN. Here, we introduce one aspect of the studies on the single-molecular mechanics of molecular motors, i. e. , myosin (II, V) and kinesin, which interact with an actin filament and a microtubule, respectively.

Based on the numerical discovery of two-dimensional amorphous photonic structures having large complete photonic gaps and structural flexibility, we propose a new optical material, namely, a photonic plate, which can be used to design arbitrarily shaped photonic mirrors and microcavities of wavelength size.

The ground state of Si(001) reconstructed surface at low temperatures had not been determined by 2003. Since 2000, when the (2x1) phase composed of symmetric dimers or symmetrically appearing dimers was proposed as the most stable phase below 20 K, a significant amount of experimental and theoretical research has been continuously performed on this issue. In determining the true ground state of Si(001) surface by low-temperature scanning tunneling microscopy (STM), we discovered that asymmetric dimer phases, c(4x2) and p(2x2), are much more stable than p(2x1). Moreover, we　discovered that the surface reconstruction phase can be controlled between the two asymmetric phases reversibly by STM. Thus, we conclude that c(4x2) is the ground state. In this article, we review the research studies on Si(001) surfaces and the present understanding of the STM manipulation of asymmetric dimer phases.

The advancement in genetic engineering has enabled us to produce and utilize various proteins for many purposes. In this paper, we describe the production of recombinant proteins using Escherichia coli or mammalian cells and also the introduction of technology for the production of a human antibody using mice as the most advanced technology in genetic engineering.

Recently, there has been considerable interest and R&D effort placed on silicon carbide (SiC) single crystals due to their applicability to low-loss and high-power electronic devices. The issue of large high-quality SiC single crystal substrates with high-quality homoepitaxial thin films is critical to the development of SiC power device technology. In this article, the current SiC crystal growth technology is outlined. The basic principles and important technological aspects of SiC bulk crystal growth and epitaxial thin film growth are described. Recent topics on this technology are also presented.