• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.55-56
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• 2006

We investigated the diffraction grating efficiency by the DPSS laser beam wavelength to improve the diffraction efficiency on AsGeSeS & Ag/ AsGeSeS thin film. Diffraction efficiency was obtained from DPSS(532nm)(P:P)polarized laser beam on AsGeSeS, Ag/ AsGeSeS and AsGeSeS/Ag/AsGeSeS thin films. As a result, for the laser beam intensity, 0.24 mW, single AsGeSeS thin film shows the highest value of 0.161% diffraction efficiency at 300 s and for 2.4 mW, it was recorded with the fastest speed of 50 s, which the diffraction grating forming speed is faster than that of 0.24 mW beam. Ag/ AsGeSeS and AsGeSeS/ Ag/ AsGeSeS multi-layered thin film also show the faster grating forming speed at 2.4 mW and higher value of diffraction efficiency at 0.24 mW.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1428-1429
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• 2006

We investigated the diffraction efficiency, erasing property and rewriting property of diffraction grating with each wavelength of recording beam. A (P:P) polarized light was exposed on AsGeSeS and Ag/AsGeSeS thin film to form a diffraction grating by HeNe(635nm) laser and DPSS(532nm) laser. At the maximum efficiency condition, unpolarized HeNe laser beam was irradiated to erase 1ha generated diffraction grating. The HeNe laser showed more higher diffraction efficiency and the DPSS laser showed more faster diffraction grating time. At erasing and rewriting process, AsGeSeS(61%-85%)thin film showed better property than Ag doped Ag/AsGeSeS(53%-63%) double layer structured thin film.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.139-144
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• 2005

Because of the photorefractive recording dynamics, each newly recorded hologram partially erases all previously stored image. Thus achieving the desired diffraction efficiency profile for the entire sequence after all images have been recorded requires exposure time schedule. The often cited classical exposure-schedule model predicts a rising-exponential build-up and an exponential decay in An with an exposure time. However because we cannot directly measure the An, it's difficult to establish the relation of both. In this paper, we deduce the relation of diffraction efficiency and exposure time from experiment data and suggest an algorithm to make time schedule profile in angle/fractal multiplexing of holographic data storage. After that, we present simulated result with equal hologram diffraction efficiency for a sequence of 250 holograms recorded by angle/fractal multiplexing.

• Journal of the Optical Society of Korea
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• v.10 no.1
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• pp.1-10
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• 2006

Optical transparency and high diffraction efficiency are two essential factors for high performance of the photopolymer. Optical transparency mainly depends on the miscibility between polymer binder and photopolymerized polymer, while diffraction efficiency depends on the refractive index modulation between polymer binder and photopolymerized polymer. For most of organic materials, the large refractive index difference between two polymers accompanies large structural difference that leads to the poor miscibility and thus poor optical quality via light scattering. Therefore, it is difficult to design a high-performance photopolymer satisfying both requirements. In this work, first, we prepared a new phase-stable photopolymer (PMMA) with large refractive index modulation and investigated the optical properties. Our photopolymer is based on modified poly (methyl methacrylate) as a polymer binder, acryl amide as a photopolymerizable monomer, triethanolamine as initiator, and yellow eosin as a photosensitizer at 532 nm. Diffraction efficiency over 85% and optical transmittance over 90% were obtained for the photopolymer. Second, Organic-inorganic nanocomposite films were prepared by dispersing an aromatic methacrylic monomer and a photo- initiator in organic-inorganic hybrid sol-gel matrices. The film properties could be controlled by optimizing the content of an organically modified silica precursor (TSPEG) in the sol-gel matrices. The photopolymer film modified with the organic chain (TSPEG) showed high diffraction efficiency (> 90%) under an optimized condition. High diffraction efficiency could be ascribed to the fast diffusion and efficient polymerization of monomers under interference light to generate refractive index modulation. The TSPEG modified photopolymer film could be successfully used for holographic memory.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1208-1211
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• 2004

When irradiated with visible light in HPDLC, photoinitiator and coinitiator produce a radical for photopolymerization. According to the kinds of photoinitiator and coinitiator, quantity and rate of produced a radical is different. It is influence on photopolymerization rate relate on diffraction efficiency. Thus, this paper is about the effect of photoinitiator/coinitiator combinations in terms of diffraction efficiency and real-time first order diffraction efficiency.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.16-27
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• 2015

Holography technology which was developed by Dennis Gabor (1900~1979) in 1948 is a technology to record wave planes of actual 3D objects. It is known as the only technology which can express 3D information most perfectly close to human-friendly. Holography technology is widely used in advertisement, architecture and arts as well as science technology areas. Especially, digital holographic print which is an applied area is greatly used in military map, architecture map and cultural asset restoration by printing and reproducing 3D information. Holography is realized by recording and reproducing the amplitude and phase information on high resolution film using coherent light like laser. Recording materials for digital holographic printer are silver halide, photoresist and photopolymer. Because the materials have different diffraction efficiency according to film characteristics of each manufacturer, appropriate guide lines should be suggested through efficiency analysis of each film. This paper suggests appropriate guide lines through the diffraction efficiency measurement of silver halide which is a holographic printer recording medium. And the objective of this study is to suggest appropriate guide lines through diffraction efficiency analysis of Ultimate 08-C and PFG-03C which are commercially used. The experiment was prepared by self-diffraction efficiency system which measures the strength with the defector by penetrating RGB recording medium and concentrating diffracted beams through collimating lens. The experiment showed Geola's PFG-03C which is a silver halide for full color has price/performance advantage in optical hologram recording, but recording angles and reproduction angles are irregular for digital holographic printer recording. Ultimate's Ultimate08-C for full color shows its diffraction efficiency is relatively stable and high according to recording angles and laser wavelength.

• Macromolecular Research
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• v.9 no.3
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• pp.171-178
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• 2001

We report the diffraction behavior of the functionalized sol-gel film composed of two different silanes. One silane (SGDR1) contains disperse red 1 (DR1) that is composed of an azobenzene unit. The other silane (SGCHC) bears a chalcone derivative that is photocrosslinkable under UV irradiation. Two-beam coupling method was employed for fabricating the diffraction gratings. The dynamics of formation and erasure of the gratings was studied in term of the variation of the diffraction efficiency. The decaying behavior of the polarization efficiency was also observed after turning off the two pump beams. For complete erasure of the diffraction gratings, we irradiated the linearly polarized single beam. During two-beam coupling, we irradiated UV light on the film surface. The effects of the photocrosslink between the double bonds in chalcone units on the value and dynamic properties of diffraction efficiency are mainly studied in this work.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.447-448
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• 2008

In this paper, we investigated the diffraction grating efficiency on AsSeS and Ag-doped amorphous chalcogenide Ag/AsSeS thin film for used to volume hologram. The film thickness was 0.5um and diffraction efficiency was obtained from (P:P) polarized He-Ne (632.8nm)laser beam on AsSeS and Ag/AsSeS thin films. As a results, diffraction grating was not formed at AsSeS thin film but at Ag-doped AsSeS thin film, diffraction grating was formed well compare with the former.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1058-1061
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• 2003

In this thesis, we observed the optical characteristic of amorphous chalcogenide thin films by He-Cd laser. Also, grating formation by He-Ne laser and He-Cd laser. After analyze diffraction efficiency of the time on the $Ag(200{\AA})/As_{40}Ge_{10}Se_{15}S_{35}$ thin films. The result diffraction efficiency of Maximun 0.2% reduced according to time grating formation by He-Ne laser. Diffraction efficiency of Maximun 0.1% showed stabiliy characteristic according to time grating formation by He-Cd laser.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.5
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• pp.403-407
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• 2010

This paper shows that the diffraction efficiency is influenced by superadditivity for the combination of the different developing agent and concentrations in the reversal bleach applied to the Slavich PFG-01 plate to be used for recording transmission holograms. The four developers based on ascorbic acid in combination with metol, phenidone, hydroquinone respectively, were studied. In diffraction efficiency aspect, the superadditivity effect of mixture of two developing agents is lower than one developing agent developer, AAC in the reversal bleach.