Browsing by Author "Hsu, Ken Y."

Now showing 1 - 20 of 32

A pyroelectric infrared biometric system for real-time walker recognition by use of a maximum likelihood principal components estimation (MLPCE) method
(2007-03-19)
Fang, Jian-Shuen
;
Hao, Qi
;
Brady, David J.
;
Guenther, Bob D.
;
Hsu, Ken Y.
This paper presents a novel biometric system for real-time walker recognition using a pyroelectric infrared sensor, a Fresnel lens array and signal processing based on the linear regression of sensor signal spectra. In the model training stage, the maximum likelihood principal components estimation ( MLPCE) method is utilized to obtain the regression vector for each registered human subject. Receiver operating characteristic ( ROC) curves are also investigated to select a suitable threshold for maximizing subject recognition rate. The experimental results demonstrate the effectiveness of the proposed pyroelectric sensor system in recognizing registered subjects and rejecting unknown subjects. (c) 2007 Optical Society of America.
An Efficient Solar Concentrator using Volume hologram
(2011)
Hsieh, Mei-Li
;
Lin, Shiuan-Huei
;
Hsu, Ken Y.
;
Burr, Jim A.
;
Lin, Shawn-Yu
In this paper, we propose a simple technique to realize a compact and nearly all-angle solar energy concentrator using a volume holographic element (VHE). Our theoretical calculation predicts up to a fivefold concentration of energy per unit area of photovoltaic material. Hence, our holographic approach can offer an exceedingly high solar-concentration, a universal solution that can be easily integrated to any solar cells. Both the analysis and design of the volume holographic element will be described and demonstrated.
Collimation testing and calibration using a heterodyne Moire method
(2014-11-01)
Chang, Wei-Yao
;
Hsu, Ken Y.
;
Chen, Kun-Huang
;
Chen, Jing-Heng
;
光電工程學系
This study proposes a simple, rapid, and highly accurate method to achieve the collimation testing and calibration of laser light beams. By applying a relative constant velocity to two gratings, every pixel of a CMOS camera can receive a series of heterodyne moire signals. Based on the least squares sine fitting algorithm, the phase of the optimized sinusoidal wave can be obtained. Consequently, the phase slope along the direction perpendicular to the grating lines can be estimated and then used to judge the degree of collimation. Furthermore, by measuring only two phase slopes at two positions of the collimating lens, the calibration of the light beam collimation can also be achieved. The experiment validated the proposed method, and the positioning error of the light beam collimation was approximately 7 mu m. (C) 2014 Elsevier Ltd. All rights reserved.
Corneal surface reconstruction by using heterodyne moire method
(2013)
Chang, Wei-Yao
;
Chen, Kun-Huang
;
Chen, Der-Chin
;
Tseng, Jung-Kai
;
Chen, Shyan-Tarng
In this paper, we propose a simple method for reconstructing the corneal surface profile by using the Talbot effect, projection moire method, and heterodyne interferometry. A linear grating is obliquely illuminated by an expanding collimated light, and a self-image of this grating can be generated and projected on the corneal surface. The deformed grating fringes are imaged on the second grating to form the moire fringes. If the first grating is moved with a constant velocity along the grating plane, a series of sampling points of the sinusoidal wave which behave like the heterodyne interferometric signal can be recorded by a CMOS camera. The phase distribution of the corneal surface then can be obtained with the IEEE 1241 least-square sine fitting algorithm and 2D phase unwrapping. Finally, the corneal surface profile can be reconstructed by substituting the phase distribution into special derived equation. This method provides the advantages of a simple optical setup, ease of operation, high stability, and high resolution.
Doped photopolymers for volume holographic applications
(2006-01-01)
Lin, Shiuan Huei
;
Lin, June-Hua
;
Hsiao, Yi-Nan
;
Hsu, Ken Y.
;
材料科學與工程學系
We fabricate two phenanthrenequinone-doped copolymers which can improve the holographic recording characteristics of phenanthrenequinone-doped poly(methyl-methacrylate) (PQ/PMMA) photopolymer. In these materials, the polymer matrix of PQ/PMMA is modified to be copolymers, which composed of either poly(methyl-methacrylate-co-trimethylolpropane-triacrylate) or poly(methyl-methacrylate-co-acrylic acid 2-phenoxyethyl ester), respectively. With the chemical analyses of these materials before and after light exposure, we investigate the physical mechanism of the holographic recording in those copolymer samples. In addition, the holographic characteristics of different samples, including dynamic range and sensitivity, have been measured. These experimental results demonstrate that modification of the monomers is an efficient method to improve the material properties.
Doped photopolymers for volume holographic applications - art. no. 631407
(2006)
Lin, Shiuan Huei
;
Lin, June-Hua
;
Hsiao, Yi-Nan
;
Hsu, Ken Y.
;
光電工程學系
We fabricate two phenanthrenequinone-doped copolymers which can improve the holographic recording characteristics of phenanthrenequinone-doped poly(methyl-methacrylate) (PQ/PMMA) photopolymer. In these materials, the polymer matrix of PQ/PMMA is modified to be copolymers, which composed of either poly(methyl-methacrylate-co-trimethylolpropane-triacrylate) or poly(methyl-methacrylate-co-acrylic acid 2-phenoxyethyl ester), respectively. With the chemical analyses of these materials before and after light exposure, we investigate the physical mechanism of the holographic recording in those copolymer samples. In addition, the holographic characteristics of different samples, including dynamic range and sensitivity, have been measured. These experimental results demonstrate that modification of the monomers is an efficient method to improve the material properties.
Doped poly(methyl methacrylate) photopolymers for holographic data storage
(2006-06-01)
Lin, Shiuan Huei
;
Lin, June-Hua
;
Chen, Po-Lin
;
Shiao, Yi -Nan
;
Hsu, Ken Y.
In this paper, we report our investigations on thick holographic recording material of the phenanthrenequinone doped poly(methyl methacrylate) (PQ:PMMA) photopolymer. The design strategy and fabrication technique for making thick polymer samples with negligible shrinkage and good optical quality are presented. The physical mechanism for holographic recording in PQ:PMMA material is described, and methods for improving are proposed. Based on these methods, photopolymer samples with different compositions are fabricated and experimentally characterized. The results show that by modifying compositions, the material sensitivity and dynamic range for volume holographic recording have been improved.
Effect of lanthanoid organometallic compounds on holographic storage characteristics of doped PQ/poly(hydroxyethyl methacrylate-co-methyl methacrylate) hybrids
(2009-12-01)
Chen, Yu-Fang
;
Hsiao, Yi-Nan
;
Lin, Shiuan Huei
;
Hsu, Ken Y.
;
Cheng, Wei-Sheng
In this research, we fabricate and characterize lanthanide organometallic compounds and 9,10-phenanthrenequinone (PQ) co-doped poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) photopolymers for holographic recording. Five different lanthanoid (Ce(3+), Nd(3+), Er(3+), Yb(3+) and Lu(3+)) organometallic compounds, one at a time, is co-doped with PQ in a poly(HEMA-co-MMA) matrix, respectively. Holographic experiments demonstrate that lutetium organometallic compounds and a PQ co-doped poly(HEMA-co-MMA) photopolymer can greatly enhance the volume holographic characteristics. The degree of improvement in hologram diffraction efficiency and the recording dynamic range for these co-doped photopolymers follows the order: Lu(3+) > Yb(3+) > Er(3+) > Nd(3+) > Ce(3+).
Fabrication and characterization of thick zinc methacrylate/phenanthrenequinone codoped poly(methyl methacrylate) photopolymers for volume holographic recording
(2006-11-01)
Hsiao, Yi-Nan
;
Whang, Wha-Tzong
;
Lin, Shiuan Huei
;
Hsu, Ken Y.
;
材料科學與工程學系
We fabricate and characterize a novel holographic recording photopolymer named ZnMA/PQ co-doped PMMA, a poly(methyl methacrylate) (PMMA) doped with two materials: zinc methacrylate (ZnMA) and 9,10-phenanthrenequinone (PQ) molecules. A technique for fabricating thick samples of 2mm thick is described. The optical and holographic characteristics of the samples are experimentally investigated. The results show that by adding ZnMA, the material M/# and sensitivity for holographic recording have been improved.
Full-field refractive index measurement with simultaneous phase-shift interferometry
(2014)
Chu, Yen-Chang
;
Chang, Wei-Yao
;
Chen, Kun-Huang
;
Chen, Jing-Heng
;
Tsai, Bo-Chung
Using the phenomenon of total internal reflection and a beam splitting device, a technique of simultaneous phase-shift interferometry is proposed for measuring the full-field refractive index. Because this method applies a beam splitting device that mimics the characteristics of beam splitting and phase modulation, four interferemetric images of various phase distributions can be simultaneously captured. Therefore, this setup can avoid errors caused by non-simultaneous capturing of images and offers the benefits of high stability, ease of operation, and real-time measurement. Furthermore, using the phenomenon of total internal reflection, the phase difference between p- and s-polarized light varies considerably with the refractive index of a tested specimen. This can substantially increase the measurement resolution. The feasibility of this method is verified using an experiment, and the measurement resolution can be higher than 3.65 x 10(-4) RIU. (C) 2014 Elsevier GmbH. All rights reserved.
Heterodyne moire interferometry for measuring corneal surface profile
(2014-03-01)
Chang, Wei-Yao
;
Chen, Kun-Huang
;
Chen, Der-Chin
;
Tseng, Jung-Kai
;
Chen, Shyan-Tarng
This study proposes an accurate method for reconstructing the corneal surface profile. By applying a constant velocity to the projection grating along the grating plane, a series of sampling points of the sinusoidal wave, which behaves in the manner of heterodyne interferometric signals, can be recorded using a CMOS camera. The phase distribution of the moire fringes can then be obtained using the IEEE 1241 least-square sine fitting algorithm and two-dimensional (2D) phase unwrapping. Finally, the corneal surface profile can be reconstructed by substituting the phase distribution into a specially derived equation. To validate the proposed method, the corneal surface of a pig eyeball was measured. The measurement resolution was approximately 3.5 mu m. Because of the introduction of the Talbot effect, the projection moire method, and heterodyne interferometry, this approach provides the advantages of a simple optical setup, ease of operation, high stability, and high resolution. (C) 2013 Elsevier Ltd. All rights reserved.
Heterodyne moire surface profilometry
(2014-02-10)
Chang, Wei-Yao
;
Hsu, Fan-Hsi
;
Chen, Kun-Huang
;
Chen, Jing-Heng
;
Hsu, Ken Y.
In this study, a novel moire fringe analysis technique is proposed for measuring the surface profile of an object. After applying a relative displacement between two gratings at a constant velocity, every pixel of CMOS camera can capture a heterodyne moire signal. The precise phase distribution of the moire fringes can be extracted using a one-dimensional fast Fourier transform (FFT) analysis on every pixel, simultaneously filtering the harmonic noise of the moire fringes. Finally, the surface profile of the tested objected can be generated by substituting the phase distribution into the relevant equation. The findings demonstrate the feasibility of this measuring method, and the measurement error was approximately 4.3 mu m. The proposed method exhibits the merits of the Talbot effect, projection moire method, FFT analysis, and heterodyne interferometry. (C) 2014 Optical Society of America
Holographic recording characteristics and physical mechanism of zinc methacrylate/nitroaniline-co-doped poly(methyl methacrylate)/9,10-phenanthrenequinone photopolymers
(2013-06-01)
Ko, Cheng-Jung
;
Chen, Po-Lin
;
Hsiao, Yi-Nan
;
Lin, Shiuan-Huei
;
Whang, Wha-Tzong
In this study we developed an approach to improve the characteristics of photopolymers for holographic data storage. Through codoping different compounds, N,N-dimethyl-4-nitroaniline (DMNA) and zinc methylacrylate (Zn(MA)2), into 9,10-phenanthrenequinone (PQ) doped poly(methyl methacrylate) (PMMA), the diffraction efficiency and the value of dynamic range (M#) have been progressed. We enhanced the diffraction efficiency (from 36.1 to 86.2%) and the dynamic range (M#, from 2.9 to 10.7) of PQ-doped PMMA through codoping with DMNA and Zn(MA)2. Using mass spectrometry and X-ray photoelectron spectroscopy, we investigated the mechanism behind the improvements in optical storage induced by the presence of Zn(MA)2 and DMNA in PMMA/PQ. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers
Identification of Protein Domains on Major Pilin MrkA That Affects the Mechanical Properties of Klebsiella pneumoniae Type 3 Fimbriae
(2012-05-15)
Chan, Chia-Han
;
Chen, Feng-Jung
;
Huang, Ying-Jung
;
Chen, Shin-Yu
;
Liu, Kuo-Liang
The Klebsiella pneumoniae type 3 fimbriae are mainly composed of MrkA pilins that assemble into a helixlike filament. This study determined the biomechanical properties of the fimbriae and analyzed 11 site-directed MrkA mutants to identify domains that are critical for the properties. Escherichia coli strains expressing type 3 fimbriae with an Ala substitution at either F34, V45, C87, G189, T196, or Y197 resulted in a significant reduction in biofilm formation. The E. coli strain expressing MrkAG189A remained capable of producing a normal number of fimbriae. Although F34A, V45A, T196A, and Y197A substitutions expressed on E. coli strains produced sparse quantities of fimbriae, no fimbriae were observed on the cells expressing MrkAC87A. Further investigations of the mechanical properties of the MrkAG189A fimbriae with optical tweezers revealed that, unlike the wild-type fimbriae, the uncoiling force for MrkAG189A fimbriae was not constant. The MrkAG189A fimbriae also exhibited a lower enthalpy in the differential scanning calorimetry analysis. Together, these findings indicate that the mutant fimbriae are less stable than the wildtype. This study has demonstrated that the C-terminal beta strands of MrkA are required for the assembly and structural stability of fimbriae.
Influence of fabrication conditions on characteristics of phenanthrenequinone-doped poly(methyl methacrylate) photopolymer for holographic memory
(2014-06-01)
Lin, Shiuan Huei
;
Cho, Sheng-Lung
;
Lin, June-Hua
;
Hsu, Ken Y.
;
Chi, Sien
In this paper, we experimentally investigate the influence of the fabrication conditions on holographic characteristics in phenanthrenequinone-doped poly(methyl methacrylate) (PQ:PMMA) bulk photopolymer. In our investigation, the PQ:PMMA bulk samples are fabricated by use of a two-step thermopolymerization method. We firstly propose to monitor relative viscosity of the monomer solution during the sample preparation to obtain a reliable criterion for material fabrication. We then compare experimentally characteristics of 2-mm thick samples fabricated with different conditions for holographic memory. The results show that the conditions in the first step play a important rule for fabricating bulk PQ:PMMA samples with good optical uniformity. In addition, the conditions in the second step play the rule for controlling the concentration of residual monomer and determine holographic characteristics. These results can provide a useful rule for fabricating bulk PQ:PMMA photopolymers for further applications on volume holographic data storage. (C) 2014 Elsevier B.V. All rights reserved.
Low-shrinkage PMMA photopolymer for volume holographic applications
(2007)
Lin, Shiuan-Huei
;
Hsu, Ken Y.
;
電子物理學系
;
Department of Electrophysics
We present the design and fabrication of extra-low shrinkage photopolymer materials for volume holographic recording. Material characterizations show that the material is promising for holographic data storage of sub-tera bytes per disk. It is also suitable for applications of multichannel image processing. Experimental demonstrations on holographic data storage and image processing will be presented.
Nitroanilines enhancing the holographic data storage characteristics of the 9,10-phenanthrenequinone-doped poly(methyl methacrylate) photopolymer
(2013-01-05)
Ko, Cheng-Jung
;
Hsiao, Yi-Nan
;
Lin, Shiuan-Huei
;
Chen, Po-Lin
;
Whang, Wha-Tzong
This article describes an approach toward improving the characteristics of a photopolymer for holographic data storage application. The maximum diffraction efficiency (?max) and dynamic range (M#) of 9,10-phenanthrenequinone (PQ)-doped poly(methyl methacrylate; PMMA) both improved significantly after co-doping with one of three nitroanilinesN,N-dimethyl-4-nitroaniline (DMNA), N-methyl-4-nitroaniline (MNA), and 4-nitroaniline (pNA). In particular, the value of ?max increased from 38% for the PMMA/PQ system to 72% for the PMMA/PQ/DMNA system (a 1.89-fold improvement) and the value of M# increased accordingly from 2.7 to 7.3 (a 2.70-fold improvement). Thus, the holographic data storage characteristics of PMMA/PQ photopolymers can be improved through co-doping with nitroaniline compounds. We also investigated the mechanism of the nitroaniline-induced improvement in optical storage performance using proton nuclear magnetic resonance and X-ray photoelectron spectroscopy. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012
Optimized design of multiport optical circulator
(2014)
Hsu, Fan-Hsi
;
Chen, Jing-Heng
;
Chen, Kun-Huang
;
Yeh, Chien-Hung
;
Hsu, Ken Y.
This research proposes a practical multiport optical circulator design by using polarizing beam splitter cubes as spatial walk-off polarizers. The use of Porro prisms for directing light requires fewer components and improves space-efficiency. Therefore, a high performance device can be produced at a reduced cost. A six-port optical circulator prototype was fabricated to show the feasibility of the proposed design. The insertion losses range between 0.52 and 1.05 dB, the isolations range between 26.20 and 45.13 dB, and the return losses are 27.72 dB. The benefits of this design\'s simple and symmetrical structure include costefficiency, simple fabrication processes, polarization-independence, the resolve of polarization-mode dispersion issues, and high performance. Additionally, the number of ports can be increased easily. (c) 2014 Elsevier GmbH. All rights reserved.
PQ-based derivatives doped PMMA photopolymers for holographic data storage
(2007)
Lin, Shiuan Huei
;
Hsiao, Yi-Nan
;
Hsu, Ken Y.
;
電子物理學系
;
Department of Electrophysics
We report our investigation on several poly(methyl methacrylate)(PMMA) photopolymers doped with different 9,10-phenanthrenequinone based derivatives for holographic data storage. By introducing different kinds of the functional groups on the doped elements, we could tailor the holographic characteristics of the materials.
PQ:DMNA/PMMA photopolymer having amazing volume holographic recording at wavelength of insignificant absorption
(2013-06-15)
Chen, Yu-Fang
;
Lin, June-Hua
;
Lin, Shiuan Huei
;
Hsu, Ken Y.
;
Whang, Wha-Tzong
N, N-dimethyl-4-nitroaniline doping enables red-light holographic recording that was originally insensitive in thick phenanthrenequinone/poly(methyl methacrylate)photopolymer to have reasonable sensitivity. A volume hologram was recorded by a 647 nm laser with maximum diffraction efficiency of about 43% in a 2-mm-thick sample. A Bragg selectivity curve and an image hologram reconstruction are also demonstrated. These experimental results support recording material for volume holographic applications in an extended red spectral range. (c) 2013 Optical Society of America