Yasuo Tomita

Prof. Yasuo Tomita

Department of Engineering Science, University of Electro-Communications, Tokyo, Japan
orcid

Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

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

Representative Publications

View All Publications
1 April 2004 in Applied Optics
Verified
Journal Article
Closed access
PDF file
NSNaoaki Suzuki
Naoaki Suzuki
Yasuo TomitaYasuo Tomita
Yasuo Tomita
We demonstrate volume holographic recording in silica-nanoparticle-dispersed methacrylate photopolymers with reduced scattering loss as low as 2%. This is made possible by use of 13-nm silica nanoparticles. As a result a net diffraction efficiency near 100% is achieved for a transmission volume hologram of 45-μm thickness. Grating buildup dynamics are measured for various nanoparticle concentrations, and the effects of nanoparticle size on refractive-index modulation and polymerization shrinkage are also evaluated.

15 April 2005 in Optics Letters
Verified
Journal Article
Closed access
PDF file
Yasuo TomitaYasuo Tomita
Yasuo Tomita
NSNaoaki Suzuki
Naoaki Suzuki
KCKatsumi Chikama
Katsumi Chikama
We report on experimental verification of mass transfer of nanoparticles during holographic recording in nanoparticle-dispersed photopolymers. Through direct observations of the microscopic structure of recorded holograms as well as optical measurements of the phase shift between the light interference pattern and a recorded hologram we find that holographic exposure causes nanoparticles to be redistributed from bright to dark regions, leading to periodic assembly of nanoparticles and thereby to formation of high-contrast holograms.

1 December 2020 in Journal of Optics
Verified
Journal Article
Open access
John SheridanJohn Sheridan
John Sheridan
RKRaymond K Kostuk
Raymond K Kostuk
AGAntonio Fimia Gil
Antonio Fimia Gil
YWY Wang
Y Wang
WLW Lu
W Lu
KSK Saravanamuttu
K Saravanamuttu

21 February 2016 in Journal of Modern Optics
Verified
Journal Article
Open access
Yasuo TomitaYasuo Tomita
Yasuo Tomita
EHEiji Hata
Eiji Hata
KMKeisuke Momose
Keisuke Momose
STShingo Takayama
Shingo Takayama
XLXiangming Liu
Xiangming Liu
MFMartin Fally
Martin Fally
We present an overview of recent investigations of photopolymerizable nanocomposite photonic materials in which, thanks to their high degree of material selectivity, recorded volume gratings possess high refractive index modulation amplitude and high mechanical/thermal stability at the same time, providing versatile applications in light and neutron optics. We discuss the mechanism of grating formation in holographically exposed nanocomposite materials, based on a model of the photopolymerization-driven mutual diffusion of monomer and nanoparticles. Experimental inspection of the recorded grating’s morphology by various physicochemical and optical methods is described. We then outline the holographic recording properties of volume gratings recorded in photopolymerizable nanocomposite materials consisting of inorganic/organic nanoparticles and monomers having various photopolymerization mechanisms. Finally, we show two examples of our holographic applications, holographic digital data storage and slow-neutron beam control.

18 May 2011 in Optical Materials Express
Verified
Journal Article
Closed access
PDF file
EHEiji Hata
Eiji Hata
KMKen Mitsube
Ken Mitsube
KMKeisuke Momose
Keisuke Momose
Yasuo TomitaYasuo Tomita
Yasuo Tomita
Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.

13 February 2006 in Applied Physics Letters
Verified
Journal Article
Closed access
PDF file
Yasuo TomitaYasuo Tomita
Yasuo Tomita
KFKouji Furushima
Kouji Furushima
KOKoichiro Ochi
Koichiro Ochi
KIKoji Ishizu
Koji Ishizu
ATAkihiro Tanaka
Akihiro Tanaka
KCKatsumi Chikama
Katsumi Chikama
We report on the use of hyperbranched polymers (HBPs) acting as mobile organic nanoparticles doped in methacrylate photopolymers for highly efficient volume holographic recording. Two types of reduced HBPs having the average size of 10nm are synthesized. The diffraction efficiency near 100% in the green (532nm) and substantive polymerization-shrinkage suppression in this photopolymer system are demonstrated. Periodic assembly of HBPs under holographic exposure is also observed.