• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.107-107
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• 2010

In this study, we have investigated the holographic grating formation on Ag-doped amorphous chalcogenide AsGeSeS thin films with Ag thickness. Ag/AsGeSeS thin films with the incident laser beam wavelength for the improvement of the polarization diffraction grating efficiency. Holographic gratings have been formed using Diode Pumped Solid State laser (DPSS, 532.0nm) under [P:P] polarized the intensity polarization holography. The diffraction efficiency was obtained by +1st order intensity. The result is shown that the diffraction efficiency of Ag/AsGeSeS double layer thin film for the Ag thickness, the maximum grating diffraction efficiency using 60nm Ag layer is 0.96%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.87-90
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• 1999

The dependence of diffraction efficiency as a funct~on of film thickness and incident angle has been investigated in amorphous chalcogenide thin films, which act as a polarization holographic materials. Especially a-(Se, S) based films exhibit a number of photoinduced phenomena not observed in other types of amorphous thin films. Holographic gratings in amorphous As-Ge-Se-S thin films have been formed using the mutual perpendicular polarized(linearly) He-Ne laser light. We could obtain the optimum condition to get high diffraction efficiency.

• Korean Journal of Optics and Photonics
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• v.20 no.4
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• pp.230-235
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• 2009

Photopolymer is evaluated as better material than the others used for hologram storage, due to many advantages, such as high diffraction efficiency, easy processing, and self-developing. In this study, chalcogenide inorganic compound ($SeO_2$) which has optical activity, was added to polyvinyl alcohol/acrylamide photopolymer films. In order to optimize diffraction efficiency of these photopolymer films, we prepared the photopolymer films with various film thicknesses and Eosin Y content. Diffraction efficiency of the photopolymer films were measured using a 532 nm laser at $40^{\circ}$ incident angle. As a result, the phtopolymer film with Eosin Y content of 0.0045 g and thickness of $297{\mu}m$ showed the highest diffraction efficiency (78.70%).

• Journal of the Korean Society for Precision Engineering
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• v.27 no.3
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• pp.18-26
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• 2010

Diffraction gratings with precise spatial periods of 2 ${\mu}m$ and 5 ${\mu}m$ have been fabricated by using a femtosecond laser which does not have limits on materials of micromachining and small thermal effects due to high peak power. Diffraction angle and diffraction efficiency of those were measured. Simulation results of diffraction angle and diffraction efficiency of the diffraction grating calculated with the parameters such as line width, depth, and spatial period of the fabricated gratings were compared with experimental results measured with a He-Ne laser. Besides these, Fresnel Zone Plates (FZPs) with focal distances of 50 mm and 25 mm were fabricated and focal distances of fabricated FZP were measured. Those experimental results for diffraction gratings and FZPs match well with experimental results.

• Journal of Broadcast Engineering
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• v.24 no.3
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• pp.452-462
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• 2019

A digital hologram, which is one of the next generation visual systems, can be generated and displayed in various formats, and a digital hologram is created in accordance with the characteristics of the system for display. Diffraction efficiency can be used as a measure of the characteristics of digital holograms generaged under various conditions in various display environments. In this paper, diffraction efficiency for computer-generated hologram (CGH) under various conditions was measured. This paper discusses the generation conditions that should be considered in hologram display. We compared each condition by measuring the intensity of the first order diffraction pattern of the fringe generated under the Fresnel condition for the phase hologram. Through this paper, we showed the tend about characteristics of the diffraction efficiency according to object point, reconstruction distance, laser and SLM.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.5
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• pp.125-131
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• 1996

In this paper, we introduced the BQBPH method for making the grating of high efficiency which was improtant in implementing optical PS. The pattern of graing was obtianed by computer simulations using iterative method, and the diffraction efficeincy of designed grating was about 67% through BPM simulation. The grating was fabricated by laser beam writer, and the diffraction efficiency BPM simulation. The grating was fabricated by laser beam writer, and the diffraction efficiency was 47%. We implemented the optical PS with the grating and showed that optical experimental output patterns were good agreement with PS output patterns and first order was main diffraction order.

• Korean Journal of Optics and Photonics
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• v.2 no.2
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• pp.89-95
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• 1991

High diffraction efficiency holographic gratings in silver halide emulsion were fabricated by using reversal bleaching process. The diffraction efficiencies of gratings were improved greatly by applying rapid drying procedure with isopropyl alcohol after bleaching with optimized developers. The dependency of diffraction efficiencies on the different groups of developers, the concentration of bleaching solutions, and the drying methods are investigated experimentally and the results were analyzed theoretically. Same as usual reversal bleaching process, the fabricated gratings showed very low scttering compared to those made by conventional bleach process. The maximum diffraction efficiency was 88%.

• Korean Journal of Optics and Photonics
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• v.3 no.3
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• pp.148-154
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• 1992

With nonhardening fixer, dichromated bleacher and alcohol drying, the diffraction efficiency of over 71o/c has been achie'{ed for holographic phase gratings in silver halide emulsion. The swollen emulsion of Agfa 8E75 HD film is identified by scanning electron microscope (SEM) after chemical processing. Dichromated bleacher and rapid dehydration using alcohol drying make a strong modulation so that diffraction efficiency is. increased over 20%. The principal characteristic parameters in coupled wave theory are investigated and new modified parameter values are presented by computer simulation. Controlling the emulsion thickness has an important role as a potential source for high diffraction efficiency.ciency.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1445-1447
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• 2001

We have investigated about the grating formation of the $a-Se_{75}-Ge_{25}$ chalcogenide thin films. In this study, holographic gratings have been formed by using He-Ne laser(632.8nm) with different polarization states(linear, circular polarization). The diffraction efficiency was obtained by +1st order intensity of the diffracted beam. We have obtained maximum efficiency for Ag-doped thin film. It is observed the difference of the diffraction efficiency with polarization states. S:S-polarized state is shown high efficiency than the other polarization.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.5
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• pp.868-873
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• 1987

Holographic diffraction gratings which are the core element of the optical instruments such as a spectrophotometer have been fabricated using the photoresist as a recording material. A 488nm line from an argon laser is used in making the gratings. Transmission type surface-relief phase grating and reflection type which is fabsricated by coating the aluminum on the transmission type with thickness 2000\ulcornerare fabricated, the spatical frequency of which are 1200 lines/mm. Diffraction efficiency, scattered light and wave-front aberratin are measured to test the performance of the developed gratings. A marimum diffraction efficiency is given when light is incident at the Bragg angle. Theoretical efficiency is about 80%, but measured efficiency of the transmission type and reflection type is 50% and 45%, respectively.