• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.18-21
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• 1996

SiO 7f the SiO/TiN film is used as the insulating layer and TiN film is chosen as the barrier against the diffusion of Al which is the terminal connected by ohmic contact because TiN has the advantageous properties such as good thermal stability and very low diffusion rate in spite of it\`s relatively low specific resistance. In this study we investigated it\`s electrical and optical characteristics to determine refractive index, absorption coefficient and Permittivity. The films are differently fabricated in thickness method for this experiment.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.801-805
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• 2004

In this work, the fundamental study of on-line monitoring of $SiO_2$ particles in the size range of 40 nm to 725 nm was carried out using turbidimetry. The size of particle was measured using a field emission scanning electron microscope (FE-SEM). The factors affecting on the turbidity were discussed, for example, wavelength, size, and concentration. In order to observe the dependence of turbidity on the wavelength, a turbidimetric system equipped with charged coupled detector (CCD) was built. The shape of the transmitted peak was changed and the peak maximum was shifted to the red when the concentration of particle was increased. This result indicates that the turbidity is related to the wavelength, which corresponds to the characteristic of the Mie extinction coefficient, Q, that is a function of not only particle diameter and refractive index but also wavelength. It is clear that a linear calibration curve for each particle in different size can be obtained at an optimized wavelength.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.128-132
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• 2013

L-Arginine semi-oxalate (LASO) single crystal has been grown by solution growth technique at room temperature. The crystal structure and lattice parameters were determined for the grown crystal by single crystal X-ray diffraction studies. Photoluminescence studies confirm the violet fluorescence emission peak at 395 nm. Optical constants like band gap, refractive index, reflectance, extinction coefficient and electric susceptibility were determined from UV-VIS-NIR spectrum. The dielectric constant, dielectric loss and ac conductivity of the compound were calculated at different temperatures and frequencies to analyze the electrical properties. The solid state parameters such as plasma energy, Penn gap, Fermi energy and polarizability were calculated to analyze second harmonic generation (SHG). Nonlinear optical property was discussed to confirm the SHG efficiency of the grown crystal.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.104-105
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• 2007

3,3-Dimethyl-1-butene($C_6H_{12}$) monomer를 이용하여 RF power와 압력에 따라 증착된 막의 refractive index와 extinction coefficient를 알아보았다. 증착된 막의 n & k는 power/pressure가 증가할수록 증가하였으며, Ar으로 증착된 막이 더 낮은 값을 갖는 것으로 나타났다.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1189-1192
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• 1993

Organic thin films were fabricated an using interelectrode capacitively coupled type plasma polymerizaion apparatus, and their optical properties were investigated. A deposition rate of styrene thin films is linearly increased, but one or vinyl-pyridine thin films is nonlinearly increased with increasing of polymerization time, pressure and monomer flow rate. The transmittance of single layer thin films is constant, but that of multi-layer appeared irregular peak with increasing of the number of layers. And then the refractive index of organic thin films is various from 1.55 to 1.65 with wavelength, the extinction coefficient indicated $10^{-3}$.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.4
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• pp.165-173
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• 1994

Retroreflector is different from other reflecting surfaces as it mades reflection in which radiation is returned in directions close to its incoming direction. Because of this characteristics, retroreflectors find many applications in traffic safety related areas. Retroreflectors are usually made using comer cubes, or partially coated glass beads. These glass beads can be made very small, so that they can be coated on sheets or mixed with paints. The design of glass type retroreflector depends on glass bead's shape and material, and its optical characteristics are related to the refractive index of glass. In this paper, a method of anlyzing glass bead type retroreflector's sptical characteristics with respect to shape and optica property of the glass, is presented. First, the coefficient of retroreflection, which is a measure of retroreflector's optical characteristics, is derived analytically using geometrical optics method. And the result is plotted using numerical methods. The results show good match with those obtained experimentally, which were supplied from a commercial retroreflector manufacturer.

• Proceedings of the Optical Society of Korea Conference
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• 2002.11a
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• pp.192-193
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• 2002

In this paper we investigate the phase modulation efficiency in the electrooptic phase modulator using PPpinNN GaAs/AlGaAs W-type waveguide. The phase change is affected by the refractive index change taking place inside the depletion region. The behavior of the modulator can be understood in terms of two electric field-related and two carrier-related effects linear electrooptic, quadratic electrooptic, plasma, and bandgap shift. As a result, the phase modulation efficiency was measured about 34.6($^{\circ}$/V$.$mm) for the TE polarized light. The quadratic electrooptic coefficient R 5.82${\times}$10$\^$-15/($\textrm{cm}^2$/V$^2$) is Obtained ant the Phase efficiency Caused by the quadratic electrooptic effect is about 10 times larger than that from the conventional linear electrooptic effect.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.2
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• pp.112-115
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• 1999

The real ($\varepsilon$1) and imaginary ($\varepsilon$2) parts of the dielectric function of ZnS have been measured by spectroscopic ellipsometry (SE) in the 3.7-6.0 eV photon-energy range at room temperature. The obtained dielectric function spectra reveal distinct structures at energies E0/(E0+$\Delta$0) and E1 critical points. The spectrum after chemical treatment to remove surface oxide overlayer showed that these data seem to be the best representation of the dielectric function of ZnS, having the largest $\varepsilon$2 value at E1 peak region reported so far by SE. Dielectric-related optical constants of ZnS, such as the complex refractive indices (n+n=ik), absorption coefficient, and reflectance, are also presented.

• Polymer(Korea)
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• v.39 no.3
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• pp.370-381
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• 2015

In the system of poly(vinyl alcohol) (PVA)/dimethyl sulfoxide, the refractive index of polymer was very well matched to that of solvent and thus its scattered intensity could be minimized. After adding small amount of polystyrene latex particle (nominal diameter 200 nm), diffusion behavior of only probe particle was investigated against the concentration of polymer matrix by means of dynamic light scattering. The polymer concentration dependence of its reduced diffusion coefficient was able to be analysed with the stretched exponential function of the reduced concentration $C[{\eta}]$. In very dilute concentration regime, the depletion layer kept constant but at the early semi-dilute regime of $1{\leq}C[{\eta}]{\leq}2.5$, the concentration-dependent exponent of depletion layer ${\delta}$ was appeared to be -0.8 which was very close to theoretical one of -0.85. However it was also observed at the higher concentration that its layer thickness decreased more abruptly than theoretical expectation and this phenomenon was ascribed to Oosawa type attractive interaction between adjacent latex particles.

• Applied Microscopy
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• v.47 no.3
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• pp.131-147
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• 2017

In this work further optical and electrical investigations of pure and Zr doped $Mn_3O_4$ (from 0 up to 20 at.%) thin films as a function of frequency. First, the refractive index, the extinction coefficient and the dielectric constants in terms of Zr content are reached from transmittance and reflectance data. The dispersion of the refractive index is discussed by means of Cauchy model and Wemple and DiDomenico single oscillator models. By exploiting these results, it was possible to estimate the plasma pulse ${\omega}_p$, the relaxation time ${\tau}$ and the dielectric constant ${\varepsilon}_{\infty}$. Second, we have performed original ac and dc conductivity studies inspired from Jonscher model and Arrhenius law. These studies helped establishing significant correlation between temperature, activation energy and Zr content. From the spectroscopy impedance analysis, we investigated the frequency relaxation phenomenon and hopping mechanisms of such thin films. Moreover, a special emphasis has been putted on the effect of the oxidation in air of hausmannite thin films to form $Mn_2O_3$ ones at $350^{\circ}C$. This intrigue phenomenon which occurred at such temperature is discussed along with this electrical study. Finally, all results have been discussed in terms of the thermal activation energies which were determined with two methods for both undoped and Zr doped $Mn_3O_4$ thin films in two temperature ranges.