• 한국전기전자재료학회논문지
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• 제16권8호
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• pp.736-739
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• 2003

We prepared the chalcogenide As$\_$40/Ge$\_$10/Se$\_$15/S$\_$35/, Se$\_$75/Ge$\_$25/ thin film. Holographic grating was formed by the He-Ne laser( λ =633 nm). Annealing at 100$^{\circ}C$ and 200$^{\circ}C$ has been used to change the optical property of chalcogenide thin films for holographic grating formation. As the results, large variation of the optical property was generated at the As$\_$40/Ge$\_$10/Se$\_$15/S$\_$35/ chalcogenide film. Diffraction efficiency of the As$\_$40/Ge$\_$10/Se$\_$15/S$\_$35/ film has been enhanced about three times

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.312-315
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• 2000

In this study, we have investigated the holography recording and reconstruction of the polarization state in chalcogenide $A_{s40}Ge_{10}Se_{15}S_{35}4 thin films using a He-Ne laser light(633nm). The thickness of thin films is a 8677${\AA}$ and 9093${\AA}$. A He-Ne laser used to probe and record of the grating. Also the polarization state of object beam modulated with a $\lambda/4$ wave plate. The polarization state of the +lst order diffracted beam generated by readout of the grating with a linearly polarized reference beam. It was the same-handed polarization state as the polarization state of the recording beam. The diffraction efficiency of circularly polarized recording represented higher than other polarization state.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.47-50
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• 1987

There are various holographic recording materials, such as Dichromated Gelatin, Silver Halide, Thermoplastic, Photoresist. In this paper especially, we used Photoresist to make the phase holographic grating. Deep-groove diffractive grating formed in relatively thin holographic recording material is to express high diffraction efficiency. Phase holographic grating recorded In photoresist can be used very practical because it has the high diffraction efficiency, and it is possible to make a replication easily. So, it has the merit in recording the optical holographic grating than any other materials.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.820-823
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• 2000

In this study, we have investigated the holography recording and reconstruction of the polarization state in chalcogenide $As_{40}$$Ge_{10}$$Se_{15}$$S_{35}$ thin films using a He-Ne laser light(633nm). The thickness of thin films is a 8677${\AA}$ and 9093${\AA}$. A He-Ne laser used to probe and record of the grating. Also the, polarization state of object beam modulated with a $\lambda/4$ wave plate. The polarization state of the +1st order diffracted beam generated by readout of the grating with a linearly polarized reference beam. It was the same-handed polarization state as the polarization state of the recording beam. The diffraction efficiency of circularly polarized recording represented higher than other polarization state.

• Macromolecular Research
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• 제17권11호
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• pp.874-878
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• 2009

Photorefractive polymer composites were synthesized based on poly (N-vinylcazbazole) (PVK) doped with liquid nonlinear optical chromophores and a sensitizer $C_{60}$. PVK/liquid NLO chromophores/$C_{60}$ devices showed no signs of phase separation and did not require a plasticizer, such as ethylcarbazole. The composites showed 69% diffraction efficiency (C3) and a rapid response time of 46 ms (C1) in four-wave mixing experiments at a light intensity of $60\;mW/cm^2$ and a wavelength of 633 nm.

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.279-280
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• 2007

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.939-942
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• 2002

The optically addressed and electrically addressed spatial phase only light modulators without pixelized structures have been developed. A sufficient phase modulation capability and a high diffraction efficiency of these devices are useful for practical applications.

• 한국광학회:학술대회논문집
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• 한국광학회 2004년도 제15회 정기총회 및 동계학술발표회
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• pp.76-77
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• 2004

• 방송공학회논문지
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• 제20권6호
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• pp.807-817
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• 2015

본 논문은 고부가가치의 콘텐츠인 디지털 홀로그램을 허락된 사용자만 볼 수 있도록 하는 암호화 방법을 제안한다. 본 논문에서는 프레넬 변환의 특성 즉, 회절거리를 증가시키면 객체영역이 상대적으로 회절평면 일부분에 집중되는 현상을 이용한다. 객체 에너지가 집중되는 영역만을 암호화함으로써 암호화 영역을 크게 줄여 적은 양을 암호화하고도 높은 암호화 효율을 얻는 방법을 제안한다. 그 방법으로는 홀로그램의 복원을 위한 프레넬 변환과 에너지 집중을 위한 프레넬 변환을 통하여 홀로그램 정보를 가운데로 집중시키고 이를 암호화하는 방법이다. 두 번째 프레넬 변환의 파라미터인 회절거리를 조절하여 에너지 집중정도를 결정하고, 가중치를 조절함으로써 암호화 영역의 크기를 조절하여 암호화 강도를 결정한다. 이를 위해 거리와 가중치에 따른 최적의 암호화 지점을 분석한다. 이 암호화 방법을 적용하였을 때 회절거리가 20m일 때 전체 영상의 0.005% ~ 0.02%만 암호화를 하여도 객체정보를 시각적으로 확인할 수 없었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.163.1-163.1
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• 2016

Lead halide perovskites CH3NH3PbX3 (X=Cl, Br, I) have received great interest in the past few years because of their excellent photoelectronic properties as well as their low-cost solution process. Their theoretical efficiency limit of the solar cell devices was predicted around 31% by a detailed balance model for the reason that exceptional light-harvesting and superior carrier transport properties. Additionally, these excellent properties contribute to the applications of optoelectronic devices such as LASERs, LEDs, and photodetectors. Since these devices are mainly using perovskite thin film, one of the most important factor to decide the efficiency of these applications is the quality of the film. Even though, optoelectrical devices are composed of polycrystalline thin film in general, not a single crystalline form which has longer carrier diffusion length and lower trap density. For these reasons, monodomain perovskite thin films have potential to elicit an optimized device efficiency. In this study, we analyzed the crystallography of the in-plane aligned perovskite thin film by X-ray diffraction (XRD) and selected area electron diffraction (SAED). Also the basic optic properties of perovskites were checked using scanning electron microscopy (SEM) and UV-Vis spectrum. From this work, the perovskite which is aligned in all directions both of out-of-plane and in-plane was fabricated and analyzed.