Browsing by Author "Lin, Shiuan Huei"

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All-optically controlled light valve assembled by photorefractive crystal and PDLC hybrid structure
(2015-01-01)
Marinova, Vera
;
Liu, Ren Chung
;
Chen, Ming Syuan
;
Lin, Shiuan Huei
;
Lin, Yi Hsin
A light-valve device, assembled by Ru-doped Bi12SiO20 (BSO) photoconductive substrate and polymer dispersed liquid crystal layer is proposed, in which all the processes are controlled by the near infrared light. Laser beam illumination (Gaussian shape) on BSO:Ru crystal caused charge carriers generation, which migrate and form an inhomogeneous distribution and subsequent space charge field. This surface-localized electromagnetic field penetrates into the PDLC layer and modulate the orientation of the liquid crystals, that caused reverse of the device initial opaque state to the highly transparent one. The proposed structure is simple and easy to fabricate, without requirements of ITO contacts and alignment layers and opens further possibilities for near-infrared applications.
Atomic Layer-Deposited Al-Doped ZnO Thin Films for Display Applications
(2020-06-01)
Dimitrov, Dimitre
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Tsai, Che-Liang
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Petrov, Stefan
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Marinova, Vera
;
Petrova, Dimitrina
The integration of high uniformity, conformal and compact transparent conductive layers into next generation indium tin oxide (ITO)-free optoelectronics, including wearable and bendable structures, is a huge challenge. In this study, we demonstrate the transparent and conductive functionality of aluminum-doped zinc oxide (AZO) thin films deposited on glass as well as on polyethylene terephthalate (PET) flexible substrates by using an atomic layer deposition (ALD) technique. AZO thin films possess high optical transmittance at visible and near-infrared spectral range and electrical properties competitive to commercial ITO layers. AZO layers deposited on flexible PET substrates demonstrate stable sheet resistance over 1000 bending cycles. Based on the performed optical and electrical characterizations, several applications of ALD AZO as transparent conductive layers are shown-AZO/glass-supported liquid crystal (LC) display and AZO/PET-based flexible polymer-dispersed liquid crystal (PDLC) devices.
Doped photopolymers for volume holographic applications
(2006-01-01)
Lin, Shiuan Huei
;
Lin, June-Hua
;
Hsiao, Yi-Nan
;
Hsu, Ken Y.
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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
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Lin, June-Hua
;
Chen, Po-Lin
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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
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Hsiao, Yi-Nan
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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+).
Efficiency Enhancement InGaP/GaAs Dual-Junction Solar Cell with Subwavelength Antireflection Nanorod Arrays
(2011-12-01)
Tsai, Min-An
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Chen, Hsin Chu
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Tseng, Ping Chen
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Yu, Peichen
;
Chiu, Chin Hua
The enhanced conversion efficiency of the InGaP/GaAs dual-junction solar cell was demonstrated utilizing broad-band and omnidirectional antireflection nanorod arrays. The nanorod arrays were fabricated by self-assembled Ni clusters, followed by inductively-coupled-plasma reactive ion etching. The conversion efficiency measured under one-sun air mass 1.5 global illuminations at room temperature was improved by 10.8%. The light absorption efficiencies of the top InGaP and bottom GaAs cells were also studied under the influence of nanorod arrays. The enhanced absorption efficiency was mostly contributed from the short wavelength absorption by top cell. Surface nanorod arrays served not only as broad-band omnidirectional antireflection layers but also scattering sources. The structure can be further optimized to obtain the maximum conversion efficiency.
Electro-optically and all optically addressed spatial light modulator devices based on organic-inorganic hybrid structures
(2017-01-01)
Marinova, Vera
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Lin, Shiuan Huei
;
Hsu, Ken Yuh
;
電子物理學系
;
光電工程學系
The paper reviews two types of organic-inorganic hybrid structures: electro-optically addressed and all optically addressed that can be used as spatial light modulator devices, operating in a transmission mode. Both hybrid devices are assembled by inorganic Bi12SiO20 (BSO) crystals and organic liquid crystals (LC). The electro-optically controlled device demonstrates very high beam-amplification values at Raman-Nath regime of diffraction whereas all optically controlled device operates at Bragg matched regime of diffraction allowing sub-micron spatial resolution. Phase modulation ability has been demonstrated supporting possibilities for applications in adaptive optics, information processing and display technologies.
Fabrication and characterization of thick zinc methacrylate/phenanthrenequinone codoped poly(methyl methacrylate) photopolymers for volume holographic recording
(2006-11-01)
Hsiao, Yi-Nan
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Whang, Wha-Tzong
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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.
FLEXIBLE AND STRETCHABLE OPTOELECTRONIC DEVICES USING GRAPHENE
(2019-01-01)
Chiou, Chung Chin
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Marinova, Vera
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Petrov, Stefan
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Fidanova, Cvetelina
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Angelova, Ina
In this paper we demonstrate flexible polymer dispersed liquid crystal (PDLC) devices using graphene as transparent conductive electrodes on polyethylene terephthalate (PET) substrate. Graphene was grown by Low Pressure Chemical Vapor Deposition (LPCVD) technique and characterized by Raman analysis, optical and electrical measurements. Several graphene-based PDLC devices have been fabricated and their electro-optical characteristics, response time and bending ability were measured and discussed. The results support the graphene promising features for integration in flexible optoelectronics.
Flexible light valves using polymer-dispersed liquid crystals and TiO2/Ag/TiO2 multilayers
(2019-06-10)
Chiou, Chung Chin
;
Hsu, Fan Hsi
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Petrov, Stefan
;
Marinova, Vera
;
Dikov, Hristosko
The era of flexible optoelectronics demands development of wearable and bendable structures, foldable touch screens, paper-like displays, and curved and flexible solid-state lighting devices. Here, we demonstrate the fabrication of highly flexible light valves using polymer-dispersed liquid crystal (PDLC) and TiO2/Ag/TiO2 transparent conductive films. TiO2/Ag/TiO2 multilayers were prepared by magnetron sputtering technique on polyethylene terephthalate (PET) substrates at room temperature. By keeping the equivalent TiO2 layers and varying the deposition time of the Ag layer, proper metal nanograins on TiO2 planar plane were formed, providing the best tradeoff between the transmittance, sheet resistance and bending ability. The results are validated by numerical simulations that suggest the best match between the deposition time and individual layer thickness. Based on the performed characteristics of TiO2/Ag/TiO2/PET structures, several flexible light valves are fabricated and characterized. The sheet resistance values of TiO2/Ag/TiO2/PET remain unchanged over 1000 bending cycles. The measured driving voltage and response time values open great potential of TiO2/Ag/TiO2/PET for integration into next-generation ITO-free flexible and stretchable devices. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Graphene oxide doped PDLC films for all optically controlled light valve structures
(2016-01-01)
Marinova, Vera
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Tong, Zhon Fang
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Petrov, Stefan
;
Karashanova, Daniela
;
Lin, Yi Hsin
We study the effect of graphene oxide (GrO) on the switching voltage of polymer dispersed liquid crystal (PDLC). The threshold voltage decreases with addition of GrO nanoparticles. Scanning electron microscopy (SEM) supported that the size of LC droplets in GrO-doped PDLC increase in comparison with non-doped one. PDLC:GrO layer was combined with Bi12SiO20 (BSO) inorganic substrate into a hybrid structure and based on the surface activated photorefractive phenomena typical for BSO, it allows the opaque-transparent states to be all optically controlled, operating faster and requiring less intensity due to the GrO addition in PDLC.
Graphene-based spatial light modulator operating at near infrared spectral range
(2019-04-01)
Marinova, Vera
;
Lin, Shiuan Huei
;
Petrov, Stefan
;
Chen, Ming Syuan
;
Lin, Yi Hsin
In this paper, a near infrared operating spatial light modulator is demonstrated, assembled in a way to combine the excellent photoconductivity of Ru-doped Bi12SiO20 (BSO:Ru) crystal, strong birefringence of liquid crystal (LC) and exceptionally high transparency and conductivity of graphene. A photo-alignment method instead of mechanical rubbing is used to simplify the fabrication procedure and to prevent detachment of the graphene layer from the substrate. The proposed device operates at low driving voltage (competitive to a reference device using ITO electrodes) moreover requires much less near infrared intensity for the light modulation. It is assumed the effect is due to the photo-induced space charge exchange between BSO:Ru and graphene allowing charge redistribution and optical doping effect resulting in a modulation of graphene's properties. The voltage-dependent transmittance and phase retardation show high contrast ratio with the response time of similar to 100 ms at 1064 nm. In addition, by projecting a video image through the proposed structure the response of modulated pump light intensity is demonstrated which supports device ability to work as near infrared optically addressed spatial light modulator (OASLM). The obtained performances reveal great potentials of graphene-based electro-optic devices for near infrared applications.
Holographic data storage with a planar-integrated optical write-read head
(2009-01-01)
Soellner, Matthias
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Vieth, Udo
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Hsu, Ken Yuh
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Lin, Shiuan Huei
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Gruber, Matthias
The construction of a write-once-read-many-type optical write-read-head for volume holographic data storage in disk-based photopolymer storage media is discussed. Its design is based on the photonic integration concept called planar-integrated free-space optics. A proof-of-principle demonstrator was fabricated, it contains a 3mm thick fused silica wafer that carries most passive components for the reference and the signal beam relay in the form of diffractive optical elements, a translucent liquid crystal microdisplay, and the CCD sensor of a webcam. Phenanthrenequinone-doped polymethylmethacrylate was chosen as storage material, a DPSS laser with lambda = 532nm serves as light source. We report about preliminary experiments to determine suitable exposure parameters for holographic write-read operations, and on the use of data matrix codes for the encoding and decoding of information.
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
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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.
Nanomechanical properties of Ag solder bumps doped with Pd and Au
(2017-12-01)
Wen, Hua-Chiang
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Chou, Wu-Ching
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Lin, Shiuan Huei
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Jiang, Don Son
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電子物理學系
As an approach to increasing their reliability, we doped Ag solder bumps with Pd and Au alloys to enhance their creep resistance, which we characterized using a nanoindentation technique. The hardnesses of the pure Ag and the Ag solders doped with Pd:3%, Pd:5%, and Pd:2%-Au:3% were 0.6 +/- 0.1, 1.8 +/- 02, 2.8 +/- 03, and 3.1 +/- 0.5 GPa, respectively. Although the hardness of the Ag solder was enhanced significantly when it contained Pd:2%-Au:3%, it exhibited a lower creep exponent (n > 2). The mechanism of the thermal recovery of the sample appears to be associated with activation of dislocation sources-also the reason for the decrease in hardness. The compounds doped with Pd:2%-Au:3% displayed significantly greater bond strengths and creep exponents, whereas the Pd only compounds exhibited poorer reliability. (C) 2017 Elsevier Ltd. All rights reserved.
Near-Infrared Holography in Ruthenium Doped Bismuth Sillenite Crystal
(2010)
Marinova, Vera
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Lin, Shiuan Huei
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Liu, Ren Chung
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Hsu, Ken Yuh
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電子物理學系
Improvement of the response speed during real-time holographic recoding is demonstrated in Ru-doped bismuth sillenite crystal at 1064 nm after green light pre-exposure. By using gating light significant operation speed of 60 ms is achieved.
Near-infrared properties of Rh-doped Bi12TiO20 crystals for photonic applications
(2013-02-15)
Marinova, Vera
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Liu, Ren Chung
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Lin, Shiuan Huei
;
Chen, Ming-Syuan
;
Lin, Yi Hsin
The effect of Rh doping in Bi12TiO20 (BTO) crystals on the photosensitivity and recording speed at 1064 nm is reported. Response time of 0.1 s is measured during real-time holographic recording without any preliminary treatments. Once the crystal is pre-excited with a green light, the detected response time becomes 0.02 s. A possibility to implement BTO:Rh crystal plate with liquid crystals into a hybrid organic/inorganic device is demonstrated, which opens perspectives for further near-infrared applications. (c) 2013 Optical Society of America
Near-infrared sensitive photorefractive device using polymer dispersed liquid crystal and BSO: Ru hybrid structure
(2014-06-01)
Liu, Ren Chung
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Marinova, Vera
;
Lin, Shiuan Huei
;
Chen, Ming-Syuan
;
Lin, Yi-Hsin
A near-infrared sensitive hybrid device, based on a Ru-doped BSO photorefractive substrate and polymer dispersed liquid crystal (PDLC) layer, is reported. It is found that the photoexcited charge carriers generated in the BSO: Ru substrate create an optically induced space charge field, sufficient to penetrate into the PDLC layer and to re-orient the LC molecules inside the droplets. Beam-coupling measurements at the Bragg regime are performed showing prospective amplification values and high spatial resolution. The proposed structure does not require indium tin oxide (ITO) contacts and alignment layers. Such a device allows all the processes to be controlled by light, thus opening further potential for real-time image processing at the near-infrared range. (C) 2014 Optical Society of America
Optical and holographic properties of Fe plus Mn co-doped Bi4Ge3O12 crystals
(2008-01-01)
Marinova, Vera
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Petrova, Dimitrina
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Lin, Shiuan Huei
;
Hsu, Ken Yuh
;
電子物理學系
The effect of iron and manganese co-doping on the light-induced, dark- and photoconductivity and holographic properties of Bi4Ge3O12 crystals in comparison with Fe- and Mn-single doping is studied. Fe+Mn co-doped crystals exhibited strong photochromic effect at room temperature, the photochromic effect being fully reversible by thermal annealing. The observed light-induced absorption changes and non-linear dependence of photoconductivity on light intensities indicate deep and shallow photoactive levels contribution to the charge transport mechanism of Fe+Mn co-doped BGO. Holographic gratings are successfully recorded at different wavelengths and a possibility to extend the photorefractive sensitivity into the red spectral range is demonstrated. It is found furthermore that Fe+Mn-doping combination leads to faster response time during holographic recording, especially after a preliminary exposure with ultraviolet light, in comparison with Fe- and Mn-single doping. (c) 2007 Elsevier B.V. All rights reserved.