Browsing by Author "Chuang, Chun-I"

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Dynamic characterization of photo-alignment of azo-dye-doped polymer using phase modulated polarimetry
(2013-01-01)
Chuang, Chun-I
;
Lin, Shivan-Huei
;
Chao, Yu-Faye
;
電子物理學系
;
光電工程學系
Using a combination of two-probe-beam phase modulated polarimetry and a waveform extraction technique, we show it is possible to determine all the optical parameters of an anisotropic medium. Particularly, we have measured the dynamic changes of refractive index ellipsoid of the disperse red 19-doped poly(methyl methacrylate) under the irradiation of linear polarized lights. The long axis of the trans molecule can be aligned to the propagation direction of P-polarized light while it is irritated by two crossed polarized lights. The refractive indices and orientation angles can be determined in one cycle of modulation (20 mu s) with sufficient precision of 10(-6) and 0.1 degrees, respectively. This work shows a new way to simultaneously monitor and control the photo-alignment process of azobenzene molecules in a polymer matrix. (c) 2012 Elsevier B.V. All rights reserved.
Phase-modulated ellipsometry for probing the temperature-induced phase transition in ruthenium-doped lead zinc niobate-lead titanate single crystal
(2011-02-28)
Chuang, Chun-I
;
Marinova, Vera
;
Lin, Shiuan-Huei
;
Chao, Yu-Faye
;
電子物理學系
Phase-modulated ellipsometry was applied to measure changes in the refractive index of pure and ruthenium (Ru)-doped 0.9Pb (Zn(1/3)Nb(2/3))O(3)(PZN)-0.1 PbTiO(3) (PT) during the heating process in real time. Both samples were heated from room temperature to 200 degrees C in a thermally insulated chamber. In both samples, the phase transitions were observed to change from tetragonal to cubic. The temperature region at which the phase transition (Curie region) of Ru-doped 0.9PZN-0.1PT occurred not only broadened but also shifted to a lower temperature. The refractive indices were extremely stable in this region, meaning that Ru-doped 0.9PZN-0.117 is a more favorable medium for the fabrication of optical memories. (C) 2011 Elsevier B.V. All rights reserved.
Rapid and accurate extraction of optical parameters for uniaxial bulk media by phase modulated ellipsometry
(2013-07-01)
Chuang, Chun-I
;
Lin, Shiuan-Huei
;
Chao, Yu-Faye
;
電子物理學系
;
光電工程學系
An improved phase modulated technique has been implemented to increase the speed and accuracy of optical parameters extraction for a uniaxial bulk media. In combination of the genetic algorithm, we show that not only the complex refractive indices, the inclination and azimuth angles of optical axis can also be extracted. Furthermore, by using a two-probe-beam configuration, the speed of convergence can be improved by 5-times. Such a high speed and accurate method can be applied for the in-situ measurement of dynamic materials. (C) 2013 Elsevier Ltd. All rights reserved.
Volume polarization holographic recording in thick phenanthrenequinone-doped poly(methyl methacrylate) photopolymer
(2011-08-15)
Lin, Shiuan Huei
;
Chen, Po-Lin
;
Chuang, Chun-I
;
Chao, Yu-Faye
;
Hsu, Ken Y.
Volume polarization holographic recording in phenanthrenequinone-doped poly (methyl methacrylate) photopolymer is obtained. Photoinduced birefringence in a 2mm thick sample is measured by a phase-modulated ellipsometry. The birefringence induced in this material by linearly polarized beam at 514nm reaches 1.2 x 10(-5). In addition, ability for recording volume polarization grating using two different polarization configurations is demonstrated and compared. The experimental results show that the diffraction efficiency of the hologram reaches to similar to 40% by using two orthogonal circularly polarized beams. (C) 2011 Optical Society of America