• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.22-26
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• 2007

In the fibre to the home (FTTH) era, it is expected that broadband network provisioning will require thousands of optical fibres to be accommodated in a central office for optical access networks. An optical fibre line testing system could be used to reduce maintenance costs and improve service availability depending on the PON's element manager capabilities and the maintenance procedures adopted by the network supplier. When monitoring optical fibres transmitting communication lights, a wavelength of 1625 nm is used for maintenance testing. The splitter installed optical filters allow the communication light to pass but that cut off the test light in the front of optical line terminals (OLTs) and optical network terminals (ONTs). In the economic point of view, We design new planer lightwave circuit splitter embedded filtter and study it optical property.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.162.6-162
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• 2001

Confocal scanning microscopy (CSM) is an important instrument in a wide variety of imaging applications because of its ability to provide three-dimensional images of thick, volume specimens. The mechanism for two-dimensional beam scanning and optical sectioning has an important roe in CSM as the three-dimensional profiler. This optical sectioning property arises from the use of a point detector, which serves to attenuate the signals from out-of-focus. The intensity profile for the open loop scanning should be matched with its response for the standard. The non-linearity can be minimized with the optical sectioning or the optical probe of the closed loop control. This paper shows the mathematical expression of the light such as the extinction curve in the optical fields of system using AO deflector, the axial/lateral response experimentally when the error sources change, and the methods of optical sectioning. Thorough design of optical sectioner is crucial to the success of CSM in the field ...

• Proceedings of the KSRS Conference
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• v.1
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• pp.324-327
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• 2006

This research is about the optical characteristic of red tide which is collected from Nam-Hae for basic research of red tide remote sensing technique development. 21 kinds of red tide organisms are cultivated to investigate optical characteristic of them on the level of laboratory, and chlorophyll specific absorption coefficient($a^*$) and backscattering coefficient($b_b^*$) are estimated by using spectrophotometer. Absorption spectrums according to species are appeared diversely from 0.005 to 0.06 (mg/ $m^2$), and the shapes of spectrums are also different. The range of $b_b^*$ are appeared $10^{-2}{\sim}10^{-4}$ mg/ $m^2$, which have around 100 times differences between species, and the shape of spectrum also have significant difference between species. These results are able to use as an input data of inverse model from ocean color.

• Applied Science and Convergence Technology
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• v.24 no.6
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• pp.250-253
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• 2015

High contrast grating (HCG) is the structure made up of the sub-wavelength grating of high-index and the surrounding layer of low-index, which reveals high contrast between two materials. Its advantages include high reflectivity over a broad bandwidth, polarization and wavelength selectivity, optical high-Q resonator, and phase modulation. In this work, the HCG structure comprising of indium tin oxide (ITO) and Silicon (Si), for the surrounding layer and the grating layer respectively, was studied. Its theoretical model was established, and transmittance, phase and optical behavior were calculated by rigorous coupled-wave analysis and finite element method. Furthermore, the established structure was fabricated to validate its feasibility. The fabricated structure shows the focusing capability whose length is about $10{\mu}m$, and the feasibility of the structure was demonstrated. It is also meaningful that ITO layer can contribute to the fabrication of the HCG structure, leading to enable the structure to be electrical-driven.

• Korean Journal of Optics and Photonics
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• v.16 no.3
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• pp.191-195
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• 2005

An optical fiber device is fabricated that is formed LPFGs only where pressure is applied, and the characteristics of the device are investigated. The fabricated device is composed of a 60cm-long metallic rod, with long period gratings of $720\;{\mu}m$ on the upper side and a rubber cover. In this device, gratings are only formed when pressure was applied to a spot, to which pressure was applied, and the formed gratings had the same transmission property regardless of spot, to which pressure was applied. We measured the optical transmission property of the fabricated device and found its usability as an optical fiber load sensor to measure weight.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.3
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• pp.194-197
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• 2013

We investigated the effect of etching time on the surface roughness, and electrical and optical properties of ZnO and 2 wt% Al-doped ZnO (AZO) films. The ZnO and AZO films were deposited on glass substrates by RF magnetron sputtering technique. The etching experiment was carried out using a solution of 5% HCl at room temperature. The surface roughness was characterized by Atomic Force Microscopy. The electrical property was measured by Hall measurement system and 4-point probe. The optical property was characterized by UV-vis spectroscopy. After the wet chemical etching, the surface textures were obtained on the surface of the ZnO and AZO films. With the increase of etching time, the surface roughness (RMS) of the films increased and the transmittance of the films was observed to decrease. For the AZO film, a low resistivity of $1.0{\times}10^{-3}\;{\Omega}{\cdot}cm$ was achieved even after the etching.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.04a
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• pp.22-23
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• 2002

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.564-569
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• 2010

Highly anti-reflective optical property has been focussed in the field of thin film and display because of increasing demands to the high transparency and clearness of optical component. In this study, to obtain anti-reflective property, the formation of aluminium oxide with nanoscaled flowerlike frame structure was introduced as oxide material monolayer on the substrate by hydrothermal synthesis through sol-gel method. The properties of coating layer were measured by the means of UV-Vis spectroscopy, FT-IR spectroscopy, XRD, and FE-SEM. The morphology of coating layer in alumina-sol coated samples was controlled by hydrothermal temperature and time with aid of ultrasound. It was found that high transparency and anti-reflective optical properties were obtained the formation of flowerlike nanoframe structure.

• Polymer(Korea)
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• v.38 no.5
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• pp.632-639
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• 2014

2,7-Dihydroxynaphthalene bis(trimellitate anhydride) (2,7-TA) was synthesized from trimellitic anhydride chloride and 2,7-dihydroxynaphthalene. Copolyimides (Co-PI) containing ester group were synthesized from 2,7-TA, pxylylenediamine, and 2,2'-bis(trifluoromethyl)benzidine (TFB). The Co-PI films were obtained from poly(amic acid) by solution casting through thermal imidization on a glass plate. The thermal property, gas permeation, and optical transparency of the Co-PI films with various TFB monomer contents were investigated. These Co-PIs could be solution-cast into a flexible and tough film. The cast Co-PI films exhibited high optical transparency with a cut-off wavelength of 370~395 nm in UV-vis. absorption and a low yellow index value of 3.55~7.63. The thermal property of Co-PI films increased linearly with increasing TFB content. However, the oxygen permeation and optical transparency of the Co-PI films was found to worsen with increasing TFB content.

• Polymer(Korea)
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• v.37 no.5
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• pp.579-586
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• 2013

Poly(vinyl alcohol)(PVA) nanocomposite films containing various saponite (SPT) clay contents were synthesized using a solution intercalation method. The thermal property, morphology, optical transparency, and gas permeability of the PVA nanocomposite films with various SPT contents in the range of 0 to 10 wt% were examined. PVA nanocomposite film containing 5 wt% SPT showed excellent thermal and gas barrier property. The hybrid films containing 5 wt% SPT were equibiaxially stretched with stretching ratios ranging from 150 to 250%. The clay dispersion, optical transparency, and gas permeability were also examined as a function of equibiaxial stretching ratio. The PVA nanocomposite films with various equibiaxial stretching ratios showed excellent optical transparency and barrier to oxygen permeability.