TRAN MINH TIEN
修士論文：「Study of vector grating element using polymer liquid crystal composites (高分子液晶複合 体を用いたベクトル型回折格子素子に関する研究)」
論 文 概 要
Diffraction grating element is widely applied in the field of
optoelectronics as an optical element for high control of light
propagation. In recent years, polarization gratings, in which optical
anisotropy is periodically modulated, are very attractive from the
point of view of their interesting optical properties including
polarization selectivity of the diffraction efficiency and polarization
conversion in the diffraction process.
It is well known that polarization-sensitive materials, in which linear and/or circular birefringence is induced by the incident polarized light, are necessary in order to record the polarization gratings. Azobenzene is one of the representatives of these materials because of axis-selective trans–cis photoisomerization reaction, which leads to holographic optical recording. Photo-cross-linkable liquid crystalline polymers (PLCPs) containing cinnamate side groups, which are photocrosslinked by irradiating them with polarized UV light, have also attracted many studies recently for expecting applies on fabricating grating.
In this study, various types of vector diffraction gratings were fabricated in two polymer liquid crystal composites, which are an azo-dye-doped liquid crystal (LC) composites (composite A) and a composite consisting of a low molecular weight LC and a PLCPs (composite B). The composite A is considered on various initial twisted orientation alignment. In particular, the higher than 90-degree twist angles can be conducted by doping chiral molecules. The vector gratings are formed in composite A by irradiation of two mutually coherent polarized beams and formed in composite B by linearly polarized exposure using galvano system. Then, the diffraction behaviors were observed to characterize the vector gratings.
||Three-dimensional vector holograms formed in twisted-nematic azo-dye-doped polymer liquid crystal composite, T. M. Tien, T. Sasaki, M. Sakamoto, K. Noda, N. Kawatsuki and H. Ono, J. Opt. Soc. Am. B 33 (2016) 286-291.|
||Three dimensional vector recording in polarization sensitive liquid crystal composites by using axisymmetrically polarized beam, M. Sakamoto, T. Sasaki, K. Noda, T. M. Tien, N. Kawatsuki and H. Ono, Opt. Lett. 41 (2016) 642-645.|
小歩岳史、Tran Minh Tien、河合孝太郎、佐々木友之、坂本盛嗣、野田浩平、川月喜弘、後藤耕平、小野浩司
Three-dimensional vector holograms formed in twisted-nematic azo dye-doped polymer liquid crystal composite
Tran Minh Tien, Tomoyuki Sasaki, Sakamoto Moritsugu, Kohei Noda, Nobuhiro Kawatsuki and Hiroshi Ono
Formation of diffraction grating in photo-cross-linkable liquid crystalline composite by using galvano mirror system
Tran Minh Tien, Takashi Shoho, Moritsugu Sakamoto, Kohei Noda, Tomoyuki Sasaki, Kohei Goto, Nobuhiro Kawatsuki, and Hiroshi Ono
小歩岳史、Tran Minh Tien、野田浩平、坂本盛嗣、佐々木友之、川月喜弘、後藤耕平、小野浩司