This article reports studies on the interaction between evanescent fi elds and nanostructures. The recent development of nanofabrication technologies enables the realizition of metallic structures that generate strongly localized electric fields with a steep gradient in the nanometer scale. If such a gradient is remarkable, the usual long wavelength approximation (LWA) is violated even for a single molecule, and hence, a dipole forbidden transition occurs. We theoretically demonstrate such peculiar molecularexcitation control using metallic nano-antennas for dimer and pentamer molecules by considering the microscopic nonlocal and self-consistent responses of molecules.

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This paper describes the recent progress of dressed photon (DP) technology. DP is a novel nanometric quasi-particle representing the coupled state of a photon, an electron, and a multimode-coherent phonon. Using DP, we developed nano-scale photonic device, i.e., nanophotonic device. Here we review ZnO quantum-well structures based nanophotonic device. In addition, recent progress in ultrafi ne fabrication technologies using DPs is reviewed, including DP-photochemical etching and desorption, which can be used to produce angstrom-scale fl at surfaces. The future outlook of these technologies is given.

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Lasers in which surface plasmon modes are amplifi ed by stimulated emission are described. Such class of lasers are called plasmonic lasers and enable us to realize nanolasers. Several kinds of plasmonic lasers have actually lased so far. In addition to these lasers, our developing plasmonic band gap lasers and our effort to reduce the scattering losses of them are also described.

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The organic thin fi lm solar cell has attracted considerable attention since a low cost solar cell fabricated by a printing process is expected. In this manuscript, a basis of the organic thin fi lm solar cell and the concept of power conversion effi ciency (PCE) enhancement are reviewed, and a printable thin fi lm solar cell based on a columnar liquid crystal showing high carrier mobility due to the self-organizing characteristics. In terms of the PCE improvement, the effectiveness of the surface plasmon resonance has been discussed.

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In this review, we present our recent progress on two dimensional (2D) crystalline sheet composed of uniformly sized silver nanoparticles. In this 2D crystalline sheet, the localized surface plasmon (LSPR) band was tuned accurately by the interparticle distance via the length of capping organic molecules. A homogeneous coupling of LSPR in 2D sheet realized not only a signifi cant red-shift but also a sharpened LSPR band. In addition, recently we found that the multilayered 2D sheet exhibited a unique plasmonic color on metal substrates depending on the number of layers (1-5 layers). This fl exible, transferable nanosheet promises new application in the field of bio-imaging. Other examples of self-assembled nanomaterials (e.g., Ag nanowires and quantum dots) reported by other groups are also introduced in this review paper.

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We present the enhancement of fl uorescence excitation with deep-UV surface plasmon resonance (DUVSPR). We selected aluminum as the material to excite DUV-SPR because it has negative permittivity and a small imaginary part in the DUV region. We demonstrated DUV-SPR excitation on aluminum fi lm with a Kretschmann confi guration, and presented the fl uorescence enhancement of quantum dots (CdSe) with DUV-SPR excitation. We increased the enhancement of fl uorescence intensity by DUVSPR. We expect that DUV-SPR will be applied for the observation of the autofl uorescence of biological samples with high sensitivity.

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Utilizing plasmon resonance, this paper describes a novel detection method of dew condensation, which continues to be seriously threatened by the recent progress of circuit miniaturization. Plasmon is the collective oscillation of free carriers in metal. Local surface plasmon resonance, which is excited on metal nanostructures, is especially attracting interest due to its ability to strongly enhance electric fi elds and sensitively detect absorbed agents by optical response changes. This feature detects water absorption with high sensitivity. Even if the water-layer thickness is smaller than the light wavelength, the optical response of the metal nanostructure drastically changes. Since a nanostructure has meso-pore structure, a plasmonic response occurs at temperatures higher than the dew point. This feature is expected to be applied to dew-condensation prevention for surrounding electronics.

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