Yoshimasa Kawata

Dr. Yoshimasa Kawata

Research Institute of Electronics, Shizuoka University, Johoku, Naka, Hamamatsu 432-8561, Japan
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Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 July 2013 in Optics Express
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AOAtsushi Ono
Atsushi Ono
MKMasakazu Kikawada
Masakazu Kikawada
RARentaro Akimoto
Rentaro Akimoto
WIWataru Inami
Wataru Inami
Yoshimasa KawataYoshimasa Kawata
Yoshimasa Kawata
We report the experimental demonstration of fluorescence enhancement in fluorescent thin film using surface plasmon excitation in deep-ultraviolet (deep-UV) region. Surface plasmon resonance in deep-UV is excited on aluminum thin film in the Kretschmann-Raether geometry. Considering the oxidation thickness of aluminum, the experimentally measured incident angle dependence of reflectance show good agreement with Fresnel theory. Surface plasmon resonance was excited at the incident angle of 49 degrees for 266 nm p-polarized excitation light on the film of 18 nm-thick aluminum with 6.5 nm-thick alumina. Fluorescence of CdS quantum dots coated on this aluminum film was enhanced to 18-fold in intensity by the surface plasmon excitation.

12 July 2004 in Applied Physics Letters
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MNMasaharu Nakano
Masaharu Nakano
TKTakaaki Kooriya
Takaaki Kooriya
TKTakashi Kuragaito
Takashi Kuragaito
CEChikara Egami
Chikara Egami
Yoshimasa KawataYoshimasa Kawata
Yoshimasa Kawata
OWOsamu Watanabe
Osamu Watanabe
We report a recording medium in which a three-dimensional nanoscale structure can be photofabricated for multilayered optical memory using a two-photon process. By fabricating the structures in the medium, we can control the shape of recorded bits and, in effect, their spatial frequency distribution. We succeeded in recording bits with a 0.5μm interval in any particular plane and 2.0μm interval between successive layers. Thus, storage density of 2.0Tbits∕cm3 is achieved.

22 February 2012 in Optics Express
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YNYasunori Nawa
Yasunori Nawa
WIWataru Inami
Wataru Inami
ACAkito Chiba
Akito Chiba
AOAtsushi Ono
Atsushi Ono
AMAtsuo Miyakawa
Atsuo Miyakawa
STSusumu Terakawa
Susumu Terakawa
We propose a direct electron-beam excitation assisted optical microscope with a resolution of a few tens of nanometers and it can be applied for observation of dynamic movements of nanoparticles in liquid. The technique is also useful for live cell imaging under physiological conditions as well as observation of colloidal solution, microcrystal growth in solutions, etc. In the microscope, fluorescent materials are directly excited with a focused electron beam. The direct excitation with an electron beam yields high spatial resolution since the electron beam can be focused to a few tens of nanometers in the specimens. In order to demonstrate the potential of our proposed microscope, we observed the movements of fluorescent nanoparticles, which can be used for labelling specimens, in a water-based solution. We also demonstrated an observation result of living CHO cells.

15 November 1998 in Optics Letters
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MIM. Ishikawa
M. Ishikawa
Yoshimasa KawataYoshimasa Kawata
Yoshimasa Kawata
CEC. Egami
C. Egami
OSO. Sugihara
O. Sugihara
NON. Okamoto
N. Okamoto
OWO. Watanabe
O. Watanabe
We present a multilayered optical memory for use in reading data with a confocal reflection microscope system. We use a recording medium in which photosensitive thin films and nonphotosensitive transparent films are stacked alternately. Since the photosensitive films are thinner than the depth of focus of the recording beam, the spatial frequency distribution of the recorded bit data is extended in the axial direction. The extended distribution overlaps the coherent optical transfer function of the reflection-type confocal microscope. Urethane–urea copolymer film is used as a photosensitive material. The recording and reading of two layers are demonstrated.

8 January 2014 in Chemphyschem
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YNYasunori Nawa
Yasunori Nawa
WIWataru Inami
Wataru Inami
SLSheng Lin
Sheng Lin
Yoshimasa KawataYoshimasa Kawata
Yoshimasa Kawata
STSusumu Terakawa
Susumu Terakawa
HCHuan‐Cheng Chang
Huan‐Cheng Chang

19 October 2001 in Physical Review B
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TITaiji Ikawa
Taiji Ikawa
TMTakuya Mitsuoka
Takuya Mitsuoka
MHMakoto Hasegawa
Makoto Hasegawa
MTMasaaki Tsuchimori
Masaaki Tsuchimori
OWOsamu Watanabe
Osamu Watanabe
Yoshimasa KawataYoshimasa Kawata
Yoshimasa Kawata
We report on the mechanism of azobenzene polymer surface deformation due to the optical near field around a dielectric sphere that is smaller than the wavelength of the incident light. We compared the deformation pattern on the surface with the calculated intensity distribution of the electric field around the sphere, and analyzed the polymer migration on the polymer surface using tapping-mode atomic force microscopy. This comparison and the polymer migration analysis show that the near-field gradient force induces the surface deformation.