Yi-Nan Hsiao

Experimental characterization of phenanthrenequinone-doped poly(methyl methacrylate) photopolymer for volume holographic storage

We present an experimental study on the photopolymer poly- (methyl methacrylate) doped with phenathrenequinone molecules. Mate- rial characteristics for holographic data storage, including optical charac- teristics, 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.

Effect of ZnMA on Optical and Holographic Characteristics of Doped PQ/PMMA Photopolymer

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.

Co-doping with polysquaraine enhances the holographic optical data storage of PMMA/PQ photopolymers

In this study, we synthesised poly(3-octylpyrrole-co-squaric acid) (PSQ3), a polysquaraine, through the reaction of 3-octylpyrrole and squaric acid, and then co-doped it with phenanthrenequinone (PQ) into poly(methyl methacrylate) (PMMA) to improve the holographic data storage characteristics of the photopolymer. The photopolymers co-doped with relatively small amounts of PSQ3 exhibited greatly improved holographic recording characteristics, including superior diffraction efficiency and dynamic range (M#). Among the samples co-doped with PQ and PSQ3, the maximum diffraction efficiency reached 54.8% (cf. 9.0% for PMMA/PQ) without further downgrade and the value of M# reached 1.05 (cf. 0.46 for PMMA/PQ). Therefore, the holographic data storage characteristics of the photopolymer PMMA/PQ were improved through co-doping with PSQ3.

Fabrication and Characterization of Thick Zinc Methacrylate/Phenanthrenequinone Codoped Poly(methyl methacrylate) Photopolymers for Volume Holographic Recording

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 2 mm 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.

Holographic characteristics of organo-metallic compound-doped PQ: PMMA photopolymers

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-PhenanthreneQuinone doped Poly(MethylMethAcrylate) (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 (~10 mW/cm2). 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.

Effect of lanthanoid organometallic compounds on holographic storage characteristics of doped PQ/poly(hydroxyethyl methacrylate-co-methyl methacrylate) hybrids

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+ ,N d 3+ , Er 3+ ,Y b 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+ .

Doped photopolymers for volume holographic applications

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.

PQ-based derivatives doped PMMA photopolymers for holographic data storage

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.

Effect of doping metal ion on holographic storage characteristics of PQ/poly(hydroxyethyl methacrylate-co-methyl methacrylate) hybrids

Holographic Storage Characteristics of PQ/poly(methyl methacrylate) have been significantly improved by doping metallic ion Yb+3 and Er+3. The hybrid materials display significant enhancement in the holographic characteristics. The diffraction efficiency promote to 59% with Yb+3, to 47% with Er+3 from the undoped sample is 40%. The increment is up to 47% in Yb+3 sample; the dynamic range enhance to 2.12 and 1.58 on Yb+3 and Er+3 containing sample individually in comparison to 1.16 for the undoped copolymer. The increment of dynamic range is up to 82% for Yb+3 containing sample. The related mechanism of these changes is preliminary discussed with the analysis of UV-vis, FT-IR and Photoluminescence spectroscopy.