• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.246-246
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• 2010

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 Chalcogenide film thickness was 0.5um and Ag thin film was varied from 10nm and 20nm. Diffraction efficiency was obtained from (P:P) polarized Diode Pumped Solid State laser(DPSS, 532.0nm: 200mW) 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.

• Korean Journal of Optics and Photonics
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• v.20 no.2
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• pp.123-127
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• 2009

In order to improve the diffraction efficiency of the photopolymer, we prepared a $TiO_2$ added photopolymer and investigated the optical properties. Prepared photopolymer films are based on polyvinyl alcohol (PVA) as a polymer binder, acryl amide (AA) as a photo-polymerizable monomer, triethanolamine (TEOA) as an initiator, and eosin Y as a sensitizer at 532 nm. To prepare the photopolymer films with the uniform thickness, the constant amount (2.5 ml) of the photopolymer solution was dropped on the glass and spread using a spin coater. Then films were dried for 72 hrs in a darkroom ($20^{\circ}C$, 40% RH) prior to the optical measurement. Then, the diffraction efficiencies of both the photopolymer films containing $TiO_2$ and non-contained films were measured with the various incident angles ($20{\sim}70^{\circ}$). Therefore, $TiO_2$ added photopolymer showed 5% higher diffraction efficiency than neat photopolymer without $TiO_2$ addition. The addition of $TiO_2$ into the photopolymer showed the high diffraction efficiency (over 70%) at broad range ($20{\sim}70^{\circ}C$) of the incident angle.

• Journal of Information Display
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• v.7 no.2
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• pp.6-11
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• 2006

New photopolymers were designed and prepared using the photosensitive polymer binders. Holographic gratings were successfully fabricated in these photopolymer samples by a conventional optical interference method. We also investigated the effect of photocrosslink in the polymer binder on the diffraction behavior of a new photopolymer. The dynamic behavior of the grating formation was monitored by changing exposure intensity in terms of the diffraction efficiency. Particularly, we focused our efforts in observing the variation of diffraction efficiency during a post UV curing process. The surface topographical change of photopolymer layer before and after Vis/UV light exposure was observed by atomic force microscope (AFM). We inscribed the gratings of the glass diffuser on the surface of the photopolymer and investigated their diffusing properties. The diffusers with photopolymer with the main chain polymer binder showed relatively good viewing angle of around ${\pm}30{\circ}$. Two kinds of photopolymer showed similar uniformity of around 47-54%.

• Journal of Information Display
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• v.5 no.1
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• pp.22-27
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• 2004

Photopolymers are quite promising candidates for holographic data storage and diffusers because of their high sensitivity and high refractive index modulation. New photopolymers were prepared using the cellulose ester binder bearing different kinds of monomer. The holographic gratings were elaborated successfully in these photopolymer samples by conventional optical interference method. We investigated the dynamic behavior of the diffraction efficiency and the effect of the functionality of the monomer doped into the polymer binder. Triacrylate monomer doped photopolymer showed the highest diffraction efficiency of around 80-90 %, even under low intensity of writing beam (I=2 mW/$cm^2$). We inscribed the gratings of the glass diffuser on the surface of the photopolymer and investigated their diffusion properties.

• Korean Journal of Optics and Photonics
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• v.31 no.4
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• pp.169-175
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• 2020

We design a polarization-independent dielectric multilayer thin-film diffraction grating for a spectral-beam-combining (SBC) system with a simple grating structure and low aspect ratio. To maintain the high quality of the SBC beam, we propose a multilayer mirror structure in which the wavefront distortion due to stress accumulation is minimized. Moreover, to prevent light absorption from contamination, an optimized design to minimize the grating thickness was performed. The optimally designed diffraction grating has 99.36% diffraction efficiency for -1st-order polarization-independent light, for incidence at the Littrow angle and 1055-nm wavelength. It is confirmed that the designed diffraction grating has sufficient process margin to secure a polarization-independent diffraction efficiency of 96% or greater.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.9
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• pp.423-428
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• 2006

We have been carried out the two-beam interference method to form the diffraction grating on chalcogenide $AS_{40}Se_{15}S_{35}Ge_{10}$ thin films for Holography Data Storage (HDS). In the present work, we have been formed holographic diffraction gratings using He-Ne laser (632.8nm) under different Polarization state combinations (intensity polarization holography, phase polarization holography). It was obtained the diffraction grating efficiency by 11st order intensity and investigated the formed grating structure using Atomic Force Microscopy (AFM). As the results, it is shown that the diffraction efficiency of (P: P) polarized recording was maximum 2.4% and we found that its value was rather higher than that of other-polarized recordings. From the results, it is confirmed that the efficient holographic grating formation on amorphous chalcogenide $AS_{40}Se_{15}S_{35}Ge_{10}$ films depend on both the spatial variation of intensity and the polarization state of the incident field pattern.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.112-114
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• 1990

A method for fabrication of holographic optical elements (HOE) using dichromated gelatin (DGG) as a recording material is presented. we describe the holographic properties of the DGG and the processing techniques. Holographic characteristics of the DGG including exposure characteristics, diffraction efficiency and angular sensitivity are also discussed. The diffraction efficiency of the obtained holographic grating is about 84%.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.69-76
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• 1999

This research was carried but to investigate the characteristics of mist removal with the change of operating conditions in the plasma reactor of impulse streamer corona based on the distribution of particle size measured by laser diffraction spectrometers. The operating conditions in this experiment were power of impulse streamer corona, gas velocity, collection time, and SOx/NOx concentration. The collection efficiency T(d) was estimated by distribution of particle size in the collection zone through the advanced model.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1505-1509
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• 2006

We use the color separation grating (CSG) to split colored light into the sub-pixel of LCD to enhance the optical efficiency as compared with that of using color filter. Based on the Fresenl diffraction theory, the theoretical optical efficiency can reach 66-81%, ranging almost from 2 to 2.5 times of that using color filters.

• Korean Journal of Optics and Photonics
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• v.6 no.4
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• pp.331-336
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• 1995

The steady-state absorption saturation of the photodarkend SDG was investigated. The absorption saturation intensity was observed to increase for the photodarkened sample. The diffraction efficiency of the permanent grating due to photodarkening was also measured using the backward DFWM technique. For the low backward pump intensity, the diffraction efficiency was proportional to the intensity of the pump beam. The origin of increasing diffraction efficiency is attributed to the difference in absorption between the permanent gratings created by photodarkening. ening.