• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.717-722
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• 2004

A design was done, and all characteristic of photodetectr of the web pattern type which a standard process of the Bipolar which Si PIN structure was used in this paper, and was used for the current amplifier design was used, and high-speed, was used as receiving optcal area of high altitude, and the module which had a low dark current characteristic was implemented with one chip with a base. Important area decreases an area of Ie at the time of this in order to consider an electrical characteristic and economy than the existing receiving IC, and performance of a product and confidence are got done in incense. First of all, the receiving IC which a spec, pattern of a wafer to he satisfied with the following electrical optical characteristic that produced receiving IC of 5V and structure are determined, and did one-chip is made. On the other hand, the time when AR layer of double is $Si_{3}N_{4}/SiO_{2}=1500/1800$ has an optical reflectivity of less than $10{\%}$ on an incidence optical wavelength of 660 ,and, in case of photo detector which reverse voltage made with 1.8V runs in 1.65V, an error about a change of thickness is very the thickness that can be improved surely. And, as for the optical current characteristic, about 5 times increases had the optical current with 274nA in 55nA when Pc was -27dBm. A BJT process is used, and receiving IC running electricity suitable for low voltage and an optical characteristic in minimum 1.8V with a base with two phases is made with one chip. IC of low voltage operates in 1.8V and 3.0V at the same time, and optical link receiving IC is going to be implemented

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.5
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• pp.272-277
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• 2006

The present study is devoted to investigate numerically the optical characteristics of multi-layer thin film structures such as $Si/SiO_2\;and\;Ge/Si/SiO_2$ by using the characteristics transmission matrix method. The reflectivity and the absorptivity rate for thin film structures are estimated for different incident angles of rays and various film thicknesses. In addition, the influence of wavelength on optical characteristics related to complex refractive index is examined. It is found that such wave-like characteristics are observed in predicting reflectivities and depends mainly on film thickness. Moreover, the present study predicts the film thickness for ignoring wave interference effects, and it also discusses the fundamental physics behind optical and energy absorption characteristics appearing in multi-layer thin film structures.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.14-15
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• 2000

We study the microwave characteristics of traveling-wave photodetector using the finite-difference time-domain method. We present two parameters for design, the width of PIN region and the thickness of i-layer, and analyze TWPD's property in frequency domain.

• Journal of the Korean Magnetics Society
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• v.4 no.3
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• pp.249-255
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• 1994

Magneto-optical disks with dielectric layers for optical tunning are useful for maximizing the SNR. We have developed a computer program based on characteristic matrix to investigate the best combination of the film thicknesses. We have optimized the thicknesses of the multilayers which were composed of TbFeCo, dielectric, and AI layers at the wavelengh of 830nm. The criterion for the optimization of the film thickness was to maximize the figure of merit with maintaining the low ellipticity and rmre than 10% reflectivity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.12
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• pp.1051-1057
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• 2000

A traveling-wave CPW(coplanar waveguide) electrode with abruptly broken input/output-taper for LiNbO$_3$optical modulator was designed and fabricated. The electrical characteristics of traveling-wave electrode on z-cut LiNbO$_3$crystal with SiO$_2$buffer layers were measured by network analyzer. To confirm the possibility of the electro-optic modulator electrode, detailed calculations of the impedance, microwave effective index and attenuation constants are presented as a function of the microwave electrode thickness, but the buffer layer thickness is fixed as 1${\mu}{\textrm}{m}$. These characteristics are discussed from the viewpoint of the device optimization and are expected to be design guides for the LiNbO$_3$modulator’s electrodes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.11
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• pp.740-744
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• 2017

Herein we studied the electrical and optical properties of indium tin oxide ITO/Ag/ITO multilayer thin films for application in transparent conducting electrodes. The ITO and Ag thin films were deposited onto soda lime glass (SLG) using radiofrequency and DC-sputtering methods, respectively. The as-synthesized ITO/Ag/ITO multilayer thin films were analyzed using 4-point probe, UV-Visible spectroscopy, and Hall measurement. We observed a rapid increase in electron concentration with increasing Ag thickness. However, electron mobility decreased with increasing Ag thickness. Finally, ITO/Ag/ITO multilayer thin films showed a characteristic low sheet resistance of $18{\Omega}/sq$ and high optical transmittance value (80%) with variation of Ag thickness (5~10 nm).

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.10
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• pp.2582-2589
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• 1993

Transient heat transfer characteristics of cooling of a spherical body were investigated in the radiatively active spherical medium. Initially the spherical body and the medium were maintained at their constant temperatures. Then heat transfer begins from spherical body t medium. The heat transfer mode inside the spherical body is just conduction. But heat is transferred by both conduction and radiation inside the medium. All thermodynamic properties were held constant in time. Spherical symmetry is assumed. DOM was adopted to solve RTE. The effect of characteries-tic optical thickness, conduction to radiation parameters, and solid surface emissivity has been studied.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2202-2207
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• 2007

The present article investigates experimentally and theoretically thermal and optical characteristics of thin film structures through measurement of thermal conductivity of Pyrex 7740 and reflectance in silicon thin film. The $3{\omega}$ method is used to measure thermal conductivity of very thin film with high accuracy and the optical characteristics in thin films are studied to examine the influence of incidence angle of light on reflectance by using the CTM(Characteristics Transmission Method) and the 633 nm He-Ne laser reflectance measurement system. It is found that the estimated reflectance of silicon show good agreement with experimental data. In particular, the present study solves the EPRT(Equation of Phonon Radiative Transport) which is based on Boltzmann transport equation for predicting thermal conductivity of nanoscale film structures. From the results, the measured thermal conductivity is in good agreement with the previous published data. Moreover, thermal conductivities are estimated for different film thickness. It indicates that as film thickness decreases, thermal conductivity decreases substantially due to internal scattering.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.6
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• pp.95-100
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• 2016

We suggest and simulate an optical filter that a red wavelength range cannot transmit to protect the psychological stress that originates from the cognition of red color in emergency medical technicians. When a nanohole hexagonal array is fabricated on gold film using Anodic Aluminum Oxide (AAO), the blocked wavelength can be tuned by the hole diameter and film thickness. The characteristic of the transmittance for normal incident white light is simulated with Finite Element Method (FEM) in the MATLAB platform. Although the transmittance of the overall wavelength is reduced by 50% by the gold film, the transmittance of the red wavelength range is decreased by over 87%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.9
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• pp.750-754
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• 2011

In this research, the electric characteristic of organic light-emitting diodes(OLEDs) was studied depending on thickness of amorphous fluoropolymer(Teflon-AF) which is the material of hole injection layer to improve electric characteristic of OLEDs. Sample composition was fabricated in double layer. The basic structure was fabricated by ITO/tris(8-hydroxyquinoline) aluminum (Alq3)/Al and the 2 layer was fabricated by ITO/2,2-Bistrifluoromethyl-4,5-Difluoro-1,3-Dioxole(Teflon-AF)/tris(8-hydro xyquinoline) aluminum (Alq3)/Al. The experiment was carried with variation of thickness of Teflon-AF at 1.0, 2.0, 2.5, 3.0 nm. The result showed when Teflon-AF thickness was 2.5 nm, the electric and optical characteristic were well performed. Moreover, when it was compared with Teflon-AF without materials, it was improved 15.1 times more on luminance, 12.7 times more on luminous efficiency and 12.1 times more on external quantum efficiency. Therefore, OLEDs element with optimum hole injection layer reduced energy barrier and driving voltage, and confirmed that it improved efficiency widely.