Browsing by Author "Hsiao, YN"

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Analyses on physical mechanism of holographic recording in phenanthrenequinone-doped poly(methyl methacrylate) hybrid materials
(2004-09-01)
Hsiao, YN
;
Whang, WT
;
Lin, SH
;
材料科學與工程學系
;
電子物理學系
The photoproducts in phenanthrenequinone (PQ)-dissolved methyl methacrylate (MMA) liquid samples and PQ-doped poly(methyl methacrylate) (PQ/PMMA) solid photopolymer samples have been analyzed by various chemical measurements. A mechanism for holographic recording in our PQ/PMMA photopolymer is proposed. By UV-VIS transmission and photoluminescence spectral measurements, we find that under light exposure the molecular structure of PQ is transformed to be less conjugated. The measured results of mass spectra, Fourier transform infrared spectra, NMR spectra, and gel permeation chromatograph of analyses provide some evidence for recognizing the molecular structure of the photoproducts in our PQ/PMMA photopolymers. The results show that under light exposure the PQ and MMA form new molecules, mainly an adduct of one PQ molecule with one MMA molecule. In addition, PQ also reacts as a photoinitiator to form PMMA oligomers in our samples. The structure change of the PQ molecule induces a strong change of the refractive index in the material. It provides a mechanism to record a phase hologram in our PQ/PMMA photopolymer. Holographic recordings in the samples are demonstrated, and the dynamic range of the sample is investigated. (C) 2004 Society of Photo-Optical Instrumentation Engineers.
Effect of ZnMA on optical and holographic characteristics of doped PQ/PMMA photopolymer
(2005-02-01)
Hsiao, YN
;
Whang, WT
;
Lin, SH
;
材料科學與工程學系
;
電子物理學系
We report on the fabrication and experimental characteristics of doping Zinc methylacrylate (ZnMA) and 9,10-phenanthrenequinone (PQ) into a poly(methyl methacrylate) (PMMA) photopolymer. The effects of a ZnMA dopant on the optical and holographic characteristics of ZnMA/PQ/PMMA have been examined. From the optical and holographic measurements of different samples with different composition ratios, we found that the time to reach the maximum diffraction efficiency has been reduced from 102 to 59 (reduced by 1.7 times) and the diffraction efficiency has been raised up from 0.57 to 1.62% (increased by 2.9 times). We also found that holographic gratings can be recorded in pure PQ-doped PMMA, but cannot be recorded in pure ZnMA-doped PMMA. The higher the concentration of PQ in codoped PMMA, the higher the diffraction efficiency. In contrast, the higher ZnMA concentration in the codoped PMMA, the shorter the response time. It is proposed that PQ serves as a photosensitive reactant and plays a major role in the formation of phase gratings. ZnMA serves as a sufficient catalyst to accelerate the reaction of PQ with a polymer or ZnMA. By adding ZnMA with a proper concentration into a PQ/PMMA photopolymer, we succeeded in improving the holographic characteristic of the photopolymer.
Experimental characterization of phenanthrenequinone-doped poly(methyl methacrylate) photopolymer for volume holographic storage
(2003-05-01)
Hsu, KY
;
Lin, SH
;
Hsiao, YN
;
Whang, WT
;
材料科學與工程學系
We present an experimental study on the photopolymer poly(methyl methacrylate) doped with phenathrenequinone molecules. Material characteristics for holographic data storage, including optical characteristics, scattering effect, relation between diffraction efficiency and number of holograms, and exposure schedule for multiple storage, are investigated. An experimental demonstration of multiple storage of digital data pages in a polymer cube is presented. (C) 2003 Society of Photo-Optical Instrumentation Engineers.
Holographic characteristics of organo-metallic compound doped PQ: PMMA photopolymers
(2004)
Hsiao, YN
;
Whang, WT
;
Lin, SH
;
Hsu, KY
;
材料科學與工程學系
Photopolymers have been applied widely in optical devices for communications. displays. bio-sensing. and data storage. The advantages of this material are easy to synthesize, high refractive index change. high sensitivity and good optical quality. Recently, we have investigated on the syntheses and analysis of 9,10-PhenaiithreneQuinone doped Poly(Methyl MethAcrylate) (PQ:PMMA) photopolymer. This material can be fabricated with large dimensions and with thickness in the range of several-centimeters. Experiments show that the material shrinkage is negligible after optical exposure such that our doped photopolymer is attractive for volume holographic applications. However. comparing with other photopolymers, our PQ:PMMA material has a drawback of lower sensitivity (similar to10 mW/cm(2)). In this presentation. we demonstrate that by adding organo-metallic compound (Zinc MethylAcrylate. ZnMA) into the PQ:PMMA photopolymer. we succeeded in reducing response time and increasing holographic diffraction efficiency of the material. We report the fabrication and experimental investigation of dye-doped photopolymer. and discuss their application for data storage.