• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04a
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• pp.195-196
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• 2000

A passband-flattening technique based on Fourier optics concept for phased-array wavelength router is presented. For easy control of optical power in each waveguide without phase correction, misaligned array waveguides are used. BPM simulation results indicate that flat passband is as wide as 75 % of the channel spacing with the insertion loss penalty of about 6 dB and with the crosstalk of about -28 dB.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.183-183
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• 2009

본 연구에선 ITO에 사용되는 Indium의 양을 줄이기 위해 ITO와 유사한 성질을 보이는 조성인 Indium - Zinc - Tin Turnary compound를 연구하였다. 각 조성은 Indium - Zinc - Tin Turnary compound를 기본으로 하여 Zinc site에 이종원소인 Al2O3와 Ga2O3를 doping함에 따라 변화되는 전기적 특성을 살며보았다. 분석에 사용한 Ceramic pellet은 일반적인 Ceramic process를 거쳐 제작되었다. 각 조성의 전기적 특성은 TCR meter와 Hall effect analyser를 이용하여 측정하였고, X-ray diffraction measurements(XRD), Scanning Electron microscope(SEM)를 이용하여 결정학적 특성을 분석하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.167-167
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• 2010

Ge-Sb-Se계 칼코게나이드 유리의 Melting 조건변화에 따른 특성변화를 연구하였다. Glass melting 조건(homogenization-temperature, homogenization-time, annealing) 에 따라 제작된 칼코게나이드 유리 bulk를 FT-IR, XRD, SEM 등의 분석장비를 이용하여 특성을 분석하였다. Homogenization temperature가 높을수록 석영관 급냉 시 발생되는 mechanical stress와 내부응력차로 인해 칼코게나이드 유리 깨짐현상이 증가하였으며 조성비와 melting 조건에 따라 XRD분석에서 확인되지 않는 미소결정이 SEM 분석결과 관찰되었다. 본 연구를 통해 칼코게나이드 유리의 melting 조건에 따른 경향성을 확인할 수 있었다.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.1-9
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• 2009

It establishes the nonlinear optics material recently on solid-state laser output side and from the infrared ray until is early has in the ultraviolet rays and the wavelength of broadband there makes be a possibility of getting the laser light which and in processing and measuring field it is widely used. Consequently, it used the pulse reiteration law from origination and nine as the fundamental wave direct plan it produced. intense it affixed the nonlinear optics material (KTP) in pulsed light and it got the green light. When inflicting a same energy in respectively reiteration mesh, intense interrelation of pulse light output and green light output between. It analyzed the conversion ratio which it follows in the mesh.

• Journal of Integrative Natural Science
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• v.6 no.2
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• pp.76-81
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• 2013

ZnO nanoparticles and vinyl pyridine were added to the mixture of MMA (methyl methacrylate), HEMA (2-hydroxy ethyl methacrylate) and NVP (N-vinylpyrrolidone) in a mould at various concentrations. Cross-linker EGDMA (ethyleneglycoldimethacrylate) and AIBN (azobisisobutyronitrile) initiator were finally added to the mixture and then heated at $80^{\circ}C$ for 60 min to prepare high-performance hydrogel ophthalmic lens. The physical properties of the hydrogel ophthalmic material were investigated by measuring the average value of refractive index, water content and optical transmittance. The refractive index of 1.429~1.450, water content of 34~41%, and visible transmittance of 78~90% were obtained. The material is possibly used to manufacture UV-block hydrogel contact lens.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.2
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• pp.149-163
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• 1994

A novel method of dimensional measurement using machine vision, which is called Landmark Tracking System, has been developed. Its advantages come form tracking only the bright, standard shaped "landmarks" which are made from retroreflective sheets. In the design of the LTS, it is essential to know the relationship between optical parameters and their influence on system performance. Such optical parameters include the brightness of landmark image, the illumination system design, and the choice of imaging optics. And the performance of retroreflective material also plays important role in the LTS performances. Influences of such optical parameters on LTS's dimensional measurement characteristics are investigated, with respect to the retroreflective material, the imaging optics, and the illumination system. Measuremtn errors due to parameter variations are also analyzed. Experiments are performed with a LTS prototype. Retroreflective characteristics are verified, and the LTS's measurement performances are measured in the form of repeatability and accuracy. Experimental results shgow that the LTS has repeatability better than 1/30,000 of a field of view(30 degrees), and accuracy better tha 1/3,000 of a field fo view.d fo view.

• Current Optics and Photonics
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• v.5 no.3
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• pp.238-242
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• 2021

In this paper, we present an in line plastic-optical-fiber (POF) temperature sensor based on intensity modulation. The in line POF temperature sensor is composed of a POF, including an in-fiber micro hole filled with reversible thermochromic material, the transmittance of which depends on temperature. The reversible thermochromic material was cobalt chloride/polyvinyl butyral gel. A cobalt chloride solution of concentration 30.8 mM was formulated using 10% water/90% ethanol (v/v) solution, and gelled by dissolving polyvinyl butyral in this solution. Four types of in line POF sensors, with in line micro holes of four different diameters, were fabricated to measure temperature in the range of 25 to 75 ℃. The output optical power of all of these in line POF temperature sensors was inversely proportional to the temperature; the relation between output power and temperature was approximately linear, and the sensitivity was proportional to the diameter of the in-fiber micro hole. The experimental results indicate that an in line POF sensor can be used effectively for measuring moderate temperatures.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.4112-4112
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• 2001

The feasibility of NIR spectroscopy as a quick and nondestructive method for quality control of uniformity of coating thickness of pharmaceutical tablets was investigated. Near infrared spectra of a set of pharmaceutical tablets with varying coating thickness were measured with a diffuse reflectance fiber optic probe connected to a Broker IFS 28/N FT-NIR spectrometer. The challenging issues encountered in this study included: 1. The similarity of the formulation of the core and coating materials, 2. The lack of sufficient calibration samples and 3. The non-linear relationship between the NIR spectral intensity and coating: thickness. A peak at 7184 $cm^{-1}$ was identified that differed for the coating material and the core material when M spectra were collected at 2 $cm^{-1}$ resolution (0.4 nm at 7184 $cm^{-1}$). The study showed that the coating thickness can be analyzed by polynomial fitting of the peak area of the selected peak, while least squares calibration of the same data failed due to the lack of availability of sufficient calibration samples. Samples of coal powder and solid pieces of coal were analyzed by FT-NIR diffuse reflectance spectroscopy with the goal of predicting their ash content, percentage of volatile components, and energy content. The measurements were performed on a Broker Vector 22N spectrometer with a fiber optic probe. A partial least squares model was constructed for each of the parameters of interest for solid and powdered sample forms separately. Calibration models varied in size from 4 to 10 PLS ranks. Correlation coefficients for these models ranged from 86.6 to 95.0%, with root-mean-square errors of cross validation comparable to the corresponding reference measurement methods. The use of FT-NIR diffuse reflectance measurement techniques was found to be a significant improvement over existing measurement methodologies in terms of speed and ease of use, while maintaining the desired accuracy for all parameters and sample forms.(Figure Omitted).

• Journal of Korean Ophthalmic Optics Society
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• v.1 no.1
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• pp.65-72
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• 1996

The general property of plastic ophthalmic lens has been reviewed by the optical property and polymer structure. A PMMA which is synthesized by the polymerization of monomers of two or more kinds is termed a copolymer, and the main chain composes a skeleton of molecular structure in the polymer. Refraction index of polymer was governed mainly by the polarization of molecular and was followed to increase it conspicuously as Cl, Br, and Iodine was substitude to hydrogen. Thermal dependence of refraction index of polymer show that the higher distinctive characteristic than glass material.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.145-148
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• 2001

SiC composites were developed by incorporating glass phase into SiC, in the light of improving mechanical properties of material for spectacle lens cutting. Specimens for spectacle lens cutting with glass phase as sintering additives have been fabricated by hot-pressing at $1810^{\circ}C$ for 2 hr under a pressure of 25 MPa. The fracture toughness and hardness of hot-pressed specimens were characterized and compared with previous works. Typical hardness and fracture toughness of materials for spectacle lens cutting were 12 GPa and $5.1MPa{\cdot}m^{1/2}$ respectively.