• Journal of Korean Ophthalmic Optics Society
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• v.4 no.1
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• pp.51-56
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• 1999

$TiO_2$ thin films were spin coated on commercial Nickel-Silver with 2%Ti-naphthanate toluene solution by sol-gel process. The thin films were heat-treated at $500^{\circ}C$ for 2min and then decorative-protective coating was obtained. The conditions for gold colored coating, and the morphology, microstructure and color of the coating surface were have been characterized by Optical microscope, Photospectrometer and XRD. The heating temperature of colored-$TiO_2$ coating was $500^{\circ}C$ and was preferable. The average thickness of 1 time coating was $0.24{\mu}m$ and the total thickness increased linearly as a function of the coating time. The color of amorphous colored-$TiO_2$ coating was changed from gold to dark redish gold with coating time. 'L' as lightness and 'b' were decreased to red, but 'a' was decreased to blue after increase with coating time.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.63-68
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• 2009

Purpose: TiN films were deposited on sus304 by unbalanced magnetron sputtering system which was designed and developed as unbalancing the strength of the magnets in the magnetron electrode. The effect of oxygen incorporation in the fabrication of deposited films was investigated. Methods: The cross sections of deposited films on Silicon wafer were observed by SEM to measure the thickness of the films, the components of the surface of the films were identified by XPS survey spectra, the compositional depth-profile of deposited films was examined by an XPS apparatus. Results: From the data of XPS depth profile of films, it could be seen that the element O as well as the elements Ti and N present in the surface of the film and the relative percentage of the element O was constant at 65 at.% with respect to the depth of film. Conclusions: The color change with thickness of the films had something to do with the change of Ti $ 2p_{3/2}$ peak intensity and shape mixed of $ TiO_2$, TiN, $ TiO_{x}N_{y}$ compound.

• Korean Journal of Optics and Photonics
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• v.9 no.5
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• pp.342-347
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• 1998

We present a theoretical analysis of Gaussian beam propagation in nonlinear Kerr media by using aberration-free approximation and Huygens-Fresnel diffraction integral and obtain a simple analytic formular for Z-scan characteristics. Z-scan experiments are carried out on amorphous $As_2S_3$ thin film and compared with the theory developed, showing good agreement. The sign and the value of ${\gamma}$ have been measured at 633 nm to be $+8.65{\times}10^{-6}\textrm{cm}^2/W$. We also measured the far-field intensity profiles, which confirm again self-focusing effect.

• Korean Journal of Optics and Photonics
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• v.25 no.5
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• pp.279-285
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• 2014

We propose an electrically controllable terahertz wave modulator based on a metamaterial and vanadium dioxide ($VO_2$) thin film. A square loop shape is designed to play the roles of both a resonating metamaterial and a heater to electrically control the conductivity of $VO_2$. The transmission characteristics of the modulator were controlled by voltage. The transmission coefficient of the modulator was stably changed from 0.27 to 0.80 at 470 GHz according to the conductivity values of $VO_2$.

• Korean Journal of Optics and Photonics
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• v.13 no.3
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• pp.228-234
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• 2002

We report theoretical investigation on the polarization selective coupling characteristics of a side-polished fiber directional coupler with a thin metal interlayer. Based on normal mode theory the coupling properties of the device under various structural conditions are analyzed. It is shown that the coupling strength between TE modes weakens rapidly with increase or metal interlayer thickness, whereas that between TM modes becomes stronger. The design conditions of the polarization splitter using the coupler to achieve high extinction ratio and low insertion loss are presented.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1407-1411
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• 2003

Due to the heat confinement in the shallow region of the target for a short time scale, pulsed laser annealing has received increasing interest for the fabrication of poly-Si thin film transistors(TFTs) on glass as a low cost substrate in the flat panel displays. The formation and growth mechanisms of poly silicon(poly-Si) grains in thin films are investigated using an excimer laser crystallization system. To understand the crystallization mechanism, the grain formations are observed by FESEM analysis. The optical reflectance and transmittance during the crystallization process are measured using HeNe laser optics. A two-step ELC(Excimer Laser Crystallization) process is applied to enhance the grain formation uniformity.

• Laser Solutions
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• v.6 no.2
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• pp.9-17
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• 2003

Due to the heat confinement in the shallow region of the target for a short time scale, pulsed laser annealing has received an increasing interest for the fabrication of poly-Si thin film transistors(TFTs) on glass as a low cost substrate in the flat panel displays. The formation and growth mechanisms of poly silicon(poly-Si) grains in thin films are investigated using an excimer laser crystallization system. To understand the crystallization mechanism, the grain formations are observed by FESEM photography. The optical reflectance and transmittance during the crystallization process are measured using HeNe laser optics. A two-step ELC(Excimer Laser Crystallization) process is applied to enhance the grain formation uniformity.

• Korean Journal of Optics and Photonics
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• v.3 no.2
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• pp.92-100
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• 1992

A Spectroscopic Ellipsorneter(SE) is fabricated. The PSA configuration of the rotating analyzer type where the effects of the imperfect optical elements can be minimized is adopted. The straight through operation shows that the standard deviations of tan$\psi$ and cos$\Delta$ are less than 0.2% in the spectral range of 300nm-850nm. From the film data of ellipsometric spectra the bulk dispersion relation of a few fluorides and the void distribution inside the fluoride thin films are obtained.

• Journal of Information Display
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• v.11 no.2
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• pp.52-56
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• 2010

High-efficiency organic light-emitting diodes (OLEDs) based on multilayer transparent electrodes (MTEs) are reported. The dielectric/metal/dielectric (DMD) multilayer electrode based on a thin silver layer achieved high sheet conductance as small as $6{\Omega}/sp$ and a tuning capability in the optical and electrical properties by engineering the inner and outer dielectric layers. In the conventional normal bottom-emitting structure, a DMD-based OLED can be fabricated with 90% higher forward luminous efficiency and 30% higher external quantum efficiency (EQE) compared to ITO-based devices. Special attention was paid to the optimization method of such MTE structure considering both the injection and optical structures.

• Korean Journal of Optics and Photonics
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• v.4 no.3
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• pp.260-265
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• 1993

An in-situ stress measurement interferometer is constructed and used to measure the intrinsic stress in Ti$O_2$ thin films during their growth by ion-assisted deposition. It is found that the stress increases with the momentum transferred by the ion beam to the growing film and is fairly well agreed with Windischmann's model. The variation of the stress with thickness is qualitatively explained in terms of the balance between the compressive stress produced by the ion beam and the surface diffusion determined by the surface temperature.