• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.260-263
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• 1990

We report the operation of an Nd+3 doped silica single mode fiber laser pumped by a 514.5nm Ar laser. A CW output power in excess of 0.27mW at 1.096um has been obtained with a sloped efficiency of 0.23% and a 15nm badnwidth.

• Proceedings of the Optical Society of Korea Conference
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• 1990.07a
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• pp.33-38
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• 1990

The carbon monoxide laser is one of useful light sources for precision laser instrumentation because of tis high efficiency and wideband characteristics. In this presentation, the liquid nitrogen cooled cw CO laser which is developed in KSRI will be reviewed

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.104-105
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2006.02a
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• pp.235-236
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• 2006

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.311-312
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• 2008

• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
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• pp.20-20
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• 1997

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.237-238
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• 2006

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.245-246
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• 2006

• Journal of the Semiconductor & Display Technology
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• v.18 no.1
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• pp.10-14
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• 2019

In this study, we synthesized two $Y_3Al_5O_{12}:Ce^{3+}$ phosphors ($7{\mu}m$-sized and $2{\mu}m$-sized YAG) with different sizes by controlling particles sizes of starting materials of the phosphors for white LED. In the smaller one ($2{\mu}m$-sized YAG), its photoluminescence intensity in the reflective mode was 63 % that of the bigger one ($7{\mu}m$-sized YAG); the quantum efficiencies were 93 % and 70 % for the smaller and the bigger ones. Two kinds of white LED packages with the same color coordinates were fabricated with a blue package (chip size $53{\times}30$) and two phosphors. The luminous flux of the white LED package with the smaller YAG phosphor was 92 % of that with the bigger one, indicating that the quantum efficiency of phosphor dispersed inside LED package was higher than that of the pure powder. It was consistently confirmed by the optical simulation (LightTools 6.3). It is notable according to the optical simulation that the white LED with the smaller phosphor showed 24 % higher luminous efficiency. If the smaller one had the same quantum efficiency as the bigger one (~93 %). Therefore, it can be suggested that the higher luminous efficiency of white LED can be possible by reducing the particle size of the phosphor along with maintaining its similar quantum efficiency.

• Journal of the Optical Society of Korea
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• v.14 no.2
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• pp.142-145
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• 2010

In this work, a numerical analysis of a CIGS ($CuIn_{1-x}Ga_xSe_2$) solar cell with a rectangular grating on the electrode is presented. The effects of the grating on the energy conversion efficiency are calculated using the RCWA (rigorous coupled wave analysis) method. In conventional CIGS solar cells, the thickness of the light absorption layer (CIGS) is $2\;{\mu}m$, at which the incident light is almost absorbed. By adopting a grating on the electrode and using a less than $1\;{\mu}m$ CIGS layer, we obtained a higher efficiency compared to the conventional solar cells.