A5036589908- Optical measurement and interference techniques
- Advanced Measurement and Metrology Techniques
- Spectroscopy and Quantum Chemical Studies
- Photochemistry and Electron Transfer Studies
- Optical Coatings and Gratings
- Photoreceptor and optogenetics research
- Surface Roughness and Optical Measurements
- Photonic and Optical Devices
- Spectroscopy Techniques in Biomedical and Chemical Research
- Force Microscopy Techniques and Applications
- Mechanical and Optical Resonators
- Advanced optical system design
- Advanced X-ray Imaging Techniques
- Digital Holography and Microscopy
- Photonic Crystals and Applications
- Molecular spectroscopy and chirality
- Ionic liquids properties and applications
- Porphyrin and Phthalocyanine Chemistry
- Radical Photochemical Reactions
- Luminescence and Fluorescent Materials
- Spectroscopy and Chemometric Analyses
- Electrochemical Analysis and Applications
- Advanced Fiber Optic Sensors
- Organic Electronics and Photovoltaics
- Advanced Chemical Physics Studies
Gakushuin University
2015-2024
University of Hyogo
2021-2023
Nihon University
2009-2020
Mejiro University
2017
The University of Tokyo
2001-2010
Technology Research Institute of Osaka Prefecture
2005-2010
National Yang Ming Chiao Tung University
2007-2010
Nara Medical University
1988-2007
Banaras Hindu University
2007
University of Hyderabad
2006
This paper proposes a method for measuring distance larger than the wavelength of light with an interferometer using laser diode. uses fact that emitted diode varies in proportion to diode's injection current. The phase difference between two interfering beams due sinusoidal variation wavelength. is detected by optical heterodyne method. magnitude proportional and shift. If shift known, can be obtained from measurement variation. kind multiwavelength interferometry single source. We have...
The excess energy dissipation process of photoexcited S1 trans-stilbene in solution has been studied with picosecond time-resolved Raman spectroscopy. peak position the 1570-cm-1 band (CC stretch) is shown to be useful as an indicator temperature changes; a spectrometer can regarded "picosecond thermometer". cooling rates thus observed 10 different solvents show strong correlation thermal diffusivities bulk solvents. Based on this observation, simple numerical model proposed for...
We propose achromatic quarter-wave plates of a subwavelength grating structure. When the period structure is smaller than wavelengths incident light, considered to be an optically anisotropic medium. The effective refractive indices strongly depend on wavelengths, especially when close wavelength. Using this feature, we can design plate whose phase retardation maintained at π/2 for wide wavelength range. A method using medium theory described, and wave designed were evaluated by numerical...
Solvent-free, nonvolatile, room-temperature alkylated-π functional molecular liquids (FMLs) are rapidly emerging as a new generation of fluid matter. However, precision design to tune their physicochemical properties remains serious challenge because the governed by subtle π-π interactions among π-units, which very hard control and characterize. Herein, we address issue probing with highly sensitive pyrene-fluorescence. A series alkylated pyrene FMLs were synthesized. The photophysical...
A time-resolved scanning infrared spectrometer has been constructed which consists of a globar light source, monochromator, an MCT detector, boxcar integrator, cw Q-switched Nd:YAG laser, and personal computer. Both the spectra (in frequency-scanning mode) temporal change transient signals time-scanning can be observed with this spectrometer. It covers spectral range 700 to 4200 cm −1 time resolution 1 μs. Intensity changes as small one part in 10 4 detected slit width 5 mm (6 at 60 4000 )...
Femtosecond time-resolved near-infrared spectra of TiO2 and Pt/TiO2 powders are measured at the wavelength region 0.9−1.5 μm with direct absorption method. Broad bands charge carriers, mainly free trapped electrons, observed for Pt/TiO2. The band shape changes a time constant 160 fs after photoirradiation, which most probably reflects trapping generated electrons. Population decay curves carriers 1 ps, obtained three different pump light powers, well-explained by second-order kinetics common...
Discussion is made of calculational reconstruction refractive index distribution from "multidirectional interferograms." Two approximate calculation formulae are given for two-dimensional case. One derived using the Born approximation and corresponds to a generalization formula in X-ray structure analysis. The other obtained Rytov's straight path approximation.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolvent/solute interactions probed by picosecond transient Raman spectroscopy: mode-specific vibrational dynamics in S1 trans-stilbeneWilliam L. Weaver, Lisa A. Huston, Koichi Iwata, and Terry GustafsonCite this: J. Phys. Chem. 1992, 96, 22, 8956–8961Publication Date (Print):October 1, 1992Publication History Published online1 May 2002Published inissue 1 October...
Abstract Optoelectronically active viscous liquids are ideal for fabricating foldable/stretchable electronics owing to their excellent deformability and predictable π-unit–based optoelectronic functions, which independent of the device shape geometry. Here we show, unprecedented ‘liquid electret’ devices that exhibit mechanoelectrical electroacoustic as well stretchability, have been prepared using solvent-free liquid porphyrins. The fluidic nature free-base alkylated-tetraphenylporphyrins...
Effective medium theory is useful for designing optical elements with a form-birefringent subwavelength structure. We describe way to determine the effective refractive indices and directions of their principal axes two-dimensional (2-D) gratings in normal incidence case. The are calculated from finite coupled-coefficient equations that used 2-D rigorous coupled-wave analysis. use calculate transmittance several kinds periodic gratings. These results compared grating analysis confirm predictions
Profile measurement taken with liquid-crystal gratings and a phase-shifting technique is proposed, its effectiveness verified by experiment. The surface profile obtained of the phase distributions sinusoidal deformed an object's surface. grating gives accurate shift, arbitrary projection pitch, constant brightness compared conventional such as laser interference fringe Ronchi grating. Therefore flexible measuring system may be developed it. Two different pitches are used to measure object...
The dynamics of the amino−imino double proton-transfer tautomerism reaction 2-aminopyridine (2AP)/acetic acid system in hexane have been investigated with steady-state absorption, fluorescence, and picosecond time-resolved fluorescence spectroscopies. It has confirmed that takes place excited state hydrogen-bonded complex 2AP acetic acid. imino tautomer shows a rise behavior 5 ps time constant at 480 nm, while decay observed 360 nm. rate this kinetics is reduced to 7 deuterium substitution....
A number of biochemical reactions proceed inside biomembranes. Because the rate a chemical reaction is influenced by properties field, it important to examine biomembranes, or lipid bilayer membranes, for understanding reactions. In this study, we estimate viscosity bilayers liposomes with picosecond time-resolved fluorescence spectroscopy. trans-Stilbene solubilized in formed phosphatidylcholines, DSPC, DOPC, DPPC, DMPC, and DLPC, 18, 16, 14, 12 carbon atoms their alkyl chains,...
Carotenoids have two major low-lying excited states, the second lowest (S2 (1Bu+)) and (S1 (2Ag–)) singlet both of which are suggested to be involved in energy transfer processes light-harvesting complexes. Studying vibrational dynamics S2 carotenoids requires ultrafast time-resolved near-IR Raman spectroscopy, although it has much less sensitivity than visible spectroscopy. In this study, relaxation mechanism β-carotene from state S1 is investigated by femtosecond multiplex absorption...
Novel regioisomeric alkylated-naphthalene liquids were designed and synthesized. In the solvent-free liquid state, 1-alkyloxy regioisomers showed excimeric luminescence, whereas 2-alkyloxy analogues exhibited monomer-rich luminescence features. Correlations among molecular structures photophysical, calorimetric, rheological properties are presented, demonstrating impact of regioisomerism on alkylated-chromophore systems.
The excited-state dynamics of pyrene incorporated into poly(substituted methylene)s is investigated by picosecond time-resolved fluorescence spectroscopy and femtosecond near-IR absorption in the 900–1400 nm region. rings are photoexcited to monomer excited state immediately after UV irradiation, followed prompt excimer formation with time constants a few picoseconds hundred picoseconds. proceeds much shorter than that pyrene-incorporated polyacrylates, vinyl polymer counterparts same...
Time-resolved fluorescence spectra and anisotropy decay of 2-aminoquinoline (2AQ) have been measured in eight room-temperature ionic liquids, including five imidazolium-based aromatic liquids three nonaromatic liquids. The same experiments also carried out several ordinary molecular for comparison. observed time-resolved indicate the formation pi-pi complexes 2AQ some but not data show unusually slow rotational diffusion suggesting solute-solvent complexes. probe molecule is likely to be...
Multifocus Raman imaging is one of the fast-imaging alternatives to conventional single point mapping technique.