• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.192-193
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• 2003

광학박막은 유리, 플라스틱, 실리콘, 금속 기판 등에서 표면의 반사율, 투과율, 흡수율과 편광상태 등의 광학적 특성을 변화시키기 위해 광학표면에 코팅을 하여 많이 사용하고 있으며, 파장영역으로는 수 nm의 연x선부터 자외선, 가시광선과 수십 $\mu$m의 적외선까지 적용할 수 있고, 광학기기에서는 대부분의 광학부품이 광학적 특성을 증진시키기 위하여 각각의 목적에 맞도록 코팅되어 있다. 광학코팅의 종류로는 단순한 무반사코팅으로부터 고반사코팅, 칼라필터, 간섭필터, 편광분리기코팅, 마이너스필터 등까지 매우 다양하다. (중략)

• Korean Journal of Optics and Photonics
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• v.8 no.5
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• pp.395-402
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• 1997

We have obtained the optimum thickness of anti-reflection(AR) coating on one of facets of a $\1.55mu\textrm{m}$ InGaAsP MQW FP semiconductor laser by in-site monitoring of the light emitted from the rear facet during the film deposition on the fore facet. The optimum thickness of $SiO_x$ thin film whose refractive index is 1.85 was found to be 188 nm. The reflectivity of the coated facet was calculated by the threshold current ratio of before and after AR coating, which was obtained from exprimental data, and it was about 2$\times$ $10^{-4}$. The results show that the output power is increased by 87% at bias current 60 mA, the slope efficiency is increased by 3.4 times, and the threshold current is increased by 2.64 times. By in-situ depositing of the $Si/SiO_2$ thin film HR coating on the rear facet, the output power was increased by 160% than before the AR and HR coatings, the slope efficiency was increased by 3.8 times, the threshold current was increased by 1.07 times, which is similar to the value of before AR coating. Due to the AR and HR coatings the output light power characteristics were enhanced.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.144-146
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• 2011

플라스틱 기판 PC 또는 ABS에 플라즈마 처리하여 접촉각을 낮출 수 있었다. Cr, Ag 등의 금속으로 스퍼터링하여 반사도 90% 이상으로 고반사 필름을 플라즈마 처리된 플라스틱에 코팅하였다. 금속질감을 갖는 표면에 컬러 코팅하여 다양한 색상을 구현하였고, 산화물 코팅층의 물성과 천이영역에 대하여 고찰하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5172-5177
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• 2011

This paper presents a reflection coating design scheme in the thin-film silicon solar cell. The antireflection(high reflection) coating skill is needed in the front(back) panel of the thin-film solar cell to improve an efficiency of light absorbing. In the single structure a reflectivity is changed according to the thickness of coating for antireflection scheme and its minimum value can be obtained by controlling thickness of coating. In the symmetric multi layer structure low reflectivity can be obtained in the wide wavelength range. And we also find that high reflectivity can be obtained through multi layer structure, which has alternate layers of high and low material, for high reflection scheme in the back panel.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.18-27
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• 2023

In this paper, the structural-thermal-optical performance analysis of the mirror was performed by setting the laser heat source as the boundary condition of the thermal analysis. For the laser heat source model, the Beer-Lambert model considering semi-transparent optical material based on Gaussian beam was selected as the boundary condition, and the mechanical part was not considered, to analyze the performance of only the mirror. As a result of the thermal analysis, thermal stress and thermal deformation data due to temperature change on the surface of the mirror were obtained. The displacement data of the surface due to thermal deformation was fitted to a Zernike polynomial to calculate the optical performance, through which the performance of the mirror when a high-energy laser was incident on the mirror could be predicted.

• Korean Journal of Optics and Photonics
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• v.20 no.5
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• pp.276-280
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• 2009

A Cr:YAG crystal was used as a saturable absorber for passive Q-switching of a Nd:$YVO_4$ laser which was pumped by a 1-W continuous wave laser diode. The first surface of the Cr:YAG was high-reflection coated for the pump wavelength. The high-reflection coating improved the absorption efficiency of the pump beam in the Nd:$YVO_4$ through double pass absorption. It also prevented pump beam induced partial bleaching of the Cr:YAG. The peak-to-peak pulse fluctuation of passively Q-switched laser output was approximately 4 %. The minimum pulse-width was measured to be 7.11 ns. Also, the average pulse repetition rate was 9 kHz and the maximum output power was 16.27 mW.

• Korean Journal of Optics and Photonics
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• v.23 no.4
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• pp.167-171
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• 2012

This paper reports on the stray light analysis results of a compact imaging spectrometer (COMIS) for a microsatellite STSAT-3. COMIS images Earth's surface and atmosphere with ground sampling distances of 27 m at the 18~62 spectral bands (0.4 ~ 1.05 ${\mu}m$) for the nadir looking at an altitude of 700 km. COMIS has an imaging telescope and an imaging spectrometer box into which three electronics PCBs are embedded. The telescope images a $27m{\times}28km$ area of Earth surface onto a slit of dimensions $11.8{\mu}m{\times}12.1mm$. This corresponds to a ground sampling distance of 27 m and a swath width of 28 km for nadir looking posture at an altitude of 700 km. Then the optics relays and disperses the slit image onto the detector thereby producing a monochrome image of the entrance slit formed on each row of detector elements. The spectrum of each point in the row is imaged along a detector column. The optical mounts and housing structures are designed in order to prevent stray light from arriving onto the image and so deteriorating the signal to noise ratio (SNR). The stray light analysis, performed by a non-sequential ray tracing software (LightTools) with three dimensional housing and lens modeling, confirms that the ghost and stray light arriving at the detector plane has the relative intensity of ${\sim}10^{-5}$ and furthermore it locates outside the concerned image size i.e. the field of view of the optics.