Chikara Egami's research while affiliated with Shizuoka University and other places

... 2 of 23 memories, 3D displays, and holographic gratings [7][8][9][10][11][12] belonging to the P-type class, thanks to their well-known good overall photochromic properties [13] and the possibility of obtaining highly responsive films. In addition, the use of diarylethenes in combination with nanoparticles (in particular gold ones) could be of great interest in this field, since the optical properties and their switching can be tuned by acting both on the nanoparticles side (mainly size and dispersion, which affect the plasma frequency) and the photochromic unit side [14][15][16][17][18][19]. ...

Reference:

Holography with Photochromic Diarylethenes

... Among them, the physical preparation method is vacuum deposition [20,21], electron beam lithography [22,23], and laser etching [24][25][26], etc. Nanostructures prepared by such methods are usually attached to various substrates while metal nanostructures synthesized by various wet chemical synthesis methods, such as nanospheres, nanorods, nanocubes, nano double cones, and core-shell nanocomposite structures usually rely on the active agent molecules adsorbed on their surfaces to maintain a stable and monodispersed state in the solution [9][10][11][12]. In recent years, researchers have conducted in-depth studies on the optical properties of metal nanostructures through a series of optical characterization techniques such as dark field [27][28][29][30], near field [31][32][33], confocal microscopy [34][35][36], as well as spectroscopy and numerical electromagnetic simulation tools [37][38][39]. They found a new phenomenon related to LSPR, which reveals that single and assembled metal nanostructures contain the basis of abundant photon-photon, photon-electron, and electron-electron interactions physical phenomenon. ...

Reference:

Zero→Two-Dimensional Metal Nanostructures: An Overview on Methods of Preparation, Characterization, Properties, and Applications

... High-energy electron irradiation produces electronic excitation/ionization in solids, which leads to many changes in their physical properties. It is known that when an electron beam passes through matter, it causes damage, which depends on the energy and flux density of the incident electron beam [2][3][4][5][6]. It is generally pictured that atomic displacements are primarily induced by elastic collisions and not by electronic excitation or ionization. ...

Reference:

Electron irradiation effects on 4-amino-5-mercapto-3-[1-(4-isobutylphenyl)ethyl]-1,2,4-triazole single crystal

... Nonlinear optics has been developed for half a century since its introduction, and the development of nonlinear optics has been significant in various fields [1,2], including optical communication [3], laser protection [4], optical switching [5,6], and three-dimensional (3D) micro-and nano-manufacturing [7]. Various nonlinear optical materials are constantly being developed and progressed. ...

Reference:

Exploration of Optical Properties of Novel Pyrene Derivatives Modified by Click Functionalization

... 153 The photoablation of NLO polymers is due to the evaporation of the material and the ablation depth is proportional to the irradiation energy. 147,[154][155][156] The SRG fabricated through photoablation is thermally stable up to a temperature higher than the T g of the polymer. Figure 15 shows the surface profile of a typical SRG on a urethane-urea copolymer observed by means of AFM. ...

Reference:

Patterned piezo-, pyro-, and ferroelectricity of poled polymer electrets

... Azobenzene and its derivatives have also been incorporated into polymers, either in the backbone or as a pendant group, to create photoresponsive materials that find applications as optical storage media and light-driven machinery. [43][44][45][46][47][48][49][50] Again, azopyridine is an attractive pendant group due to its hydrogen bonding ability. The hydrogen bonding network allows polymers containing this building block to form unique supramolecular architectures that expand polymer functionality. ...

Reference:

The doorstop proton: acid-controlled photoisomerization in pyridine-based azo dyes †

... In this article we have chosen urethane-urea copolymer containing azo chromophore at the side chain. Laser-induced morphological change of such a functionalized polymer film has received much attention as possible device fabrication of materials for future optical devices [29][30][31], high density memory [32,33], and so on. It is widely known that irradiation of light to the azo chromophore induces photoisomerization and photoreduction, so that elucidation of laser ablation mechanism of this polymer film is interesting for photophysical and photochemical study. ...

Reference:

Excitation Wavelength Dependence of Laser Ablation Mechanism of Urethane-Urea Copolymer Film Studied by Time-Resolved Absorbance Measurements

... The first generation of fiber-based optical sensors emerged around 1980. 20,21 In the following years, absorption or fluorescent-based pH indicators were incorporated in polymers, such as polystyrene, 22 polyacrylamide, 23,24 polyIJmethyl methacrylate) (PMMA), 25,26 and deposited on the fiber tip. Because of the high sensitivity, fluorescence sensors have been more extensively studied than other types of colorimetric sensors. ...

Reference:

Incorporating fluorescent nanomaterials in organically modified sol–gel materials – creating single composite optical pH sensors

... This simple technique is applicable to most of the NLO polymer films with short process time and low cost. 128 Another patterning method that also relies on a PDMS mold is micromolding in capillaries ͑MIMIC͒. [129][130][131] In MIMIC, a PDMS stamp with a suitable surface-relief structure is conformally laid onto the substrate, thus, generating a network of capillaries between the two layers. ...

Reference:

Patterned piezo-, pyro-, and ferroelectricity of poled polymer electrets

... Near-field scanning optical microscopy (NSOM/SNOM) had broken the far field resolution limit by exploiting the properties of evanescent waves. Applications of near-field optics to lithography on photosensitive polymers assisted by AFM measurements (non-optically probing near-field microscopy) gave a resolution less than 100 nm [3][4][5][6][7]. Three research groups [8][9][10] have developed new optical techniques based on Stimulated Emission Depletion (STED) [11] with interesting results (l/10-l/20 resolution). ...

Reference:

2 nm Quantum Optical Lithography