• 연구논문집
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• s.33
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• pp.111-122
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• 2003

The automatic assembly system of micro optical filter is a key technology in the development of optical modules with high functionality. In order to create such automatic assembly system of optical filter, we have developed the system and program capable of evaluation of $30\mum$-thick film optical filter as well as conventional optical filters performances. Moreover, we have carried out the evaluation of optical filter using developed system and program, and we have compared and analyzed them with by conventional hand work. As results, the measured performances based on the present system are more fast, precise and reliable then those of the conventional hand work. In addition to that, the system can apply for various optical collimators and filters.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.31 no.11
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• pp.141-145
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• 1982

Optical absorption properties of an orphous Se film due to interband electronic transitions are observed in the visible range by varying the folm thickness. Amorphous Se films were prepared by evaporation method. As the experimental results, it is found that optical energy gap is around 2.07(e V), and the optical constants depend on the film thickness, evaporation-deposition conditions, and incident photon energy.

• Korea-Australia Rheology Journal
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• v.15 no.3
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• pp.117-124
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• 2003

Elastohydrodynamic lubrication (EHL) film is measured under the condition of viscosity index improver added to base oil. In-situ optical contact method using the interference principle make the measuring resolution of ~5 nm possible and enables the measuring range all over the contact area of up to ~300 $\mu\textrm{m}$ diameter. What is more important to the developed method by the author is that the measurement of EHL film thickness is possible in the range from 100 nm to 2 $\mu\textrm{m}$, which is the regime of worst contact failures in precision machinery. Viscosity index improver (VII) is one of the major additives to the modem multigrade lubricants for the viscosity stability against temperature rise. However, it causes shear thinning effects which make the film thickness lessened very delicately at high shear rate (over $10^5 s^{-1}$) of general EHL contact regime. In order to exactly verify the VIIs performance of viscosity stability at such high shear rate, it is necessary to make the measurement of EHL film thickness down to ~100 nm with fine resolution for the preliminary study of viscosity control. In this work, EHL film thickness of VII added lubricant is measured with the resolution of ~5 nm, which will give very informative design tool for the synthesis of lubricants regarding the matter of load carrying capacity at high shear rate condition.

• Korean Journal of Materials Research
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• v.3 no.4
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• pp.388-394
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• 1993

The state of aggregation and optical contrast of poly(vinyl chlorich, )(PVC)!nematic liquid crystal(LC) composite film liave been studied for a wide range(30~70 wt% LC)of film composition. In addition. effects of temperature, frequency and voltage of the applied AV electric field on the film transmittance have heen measured for a film containing (6O wt % I, C, which showed maximum optical contrast. For this particular composition of film, tlw thn'shold voltage was smalkr than .40$V_{p-p}$ at I kHZ, $25^{\circ}C$, and the rise time and decay time were smalle, r than l0Oms at 100$V_{p-p}$, I kHz, and $25^{\circ}C$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2247-2252
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• 2012

In this paper, we produced CIGS thin film by co-evaporation method. During the process, substrate temperature and Ga/(In+Ga) composition ratio was altered to observe the change of resistivity and absorbance spectra measurements. As substrate temperature increased, resistivity decreased and as Ga/(In+Ga) composition ratio increased from 0.30 to 0.72, band gap also increased with the range of 1.26eV, 1.30eV, 1.43eV, 1.47eV. With the constant condition of composition ratio, resistivity decreased with increased thickness of the thin film. On this experiment, we assumed that optical absorbance ratio and optical current will be increased with CIGS thin film fabrication.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.1
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• pp.7-11
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• 2015

In this study, $Si_3N_4$/SnZnO/AZO/Ag/Ti/ITO multi-layer film were prepared on glass substrate by DC/RF magnetron sputtering method. To prevent interfacial reaction between Ag and ITO layer, Ti buffer layer was inserted. Optical properties and sheet resistance were studied depending on laminating times of each multi-layered film especially in visible ray. The simulation program, EMP (essential macleod program), was adopted and compared with experimental data to expect the experimental result. It was found out that the transmittance of the first stacked $Si_3N_4$/SnZnO/AZO/Ag/Ti/ITO multi-layer film was more than 90%. However, with increasing stacking times, the optical properties of $Si_3N_4$/SnZnO/AZO/Ag/Ti/ITO multi-layer film get worse. Consequently, Ti layer is good for oxidation barrier, but too many uses of this layer may have an adverse effect to optical properties of TCO film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.451-452
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• 2006

We studied the electro-optical characteristic of vertical alignment liquid crystal display(VA-LCD) on the $SiO_x$ thin film deposited $45^{\circ}$ oblique by rf magnetic sputtering system. LC alignment characteristic showed homeotropic alignment, and pretilt angle was about $90^{\circ}$. A uniform liquid crystal alignment effect on the $SiO_x$ thin film was achieved and the electro-optical characteristic of the $SiO_x$ thin film deposited $45^{\circ}$ oblique by rf magnetic sputtering system was excellent.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.454-454
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• 2010

In order to achieve a high efficient a-Si solar cell, the TCO (transparent conductive oxide) substrates are required to be a low sheet resistivity, a high transparency, and a textured surface with light trapping effect. Recently, a zinc oxide (ZnO) thin film attracts our attention as new coating material having a good transparent and conductive for TCO of solar cells. In this paper the optical properties of $H_2$ post-treated BZO (boron doped ZnO, ZnO:B) thin film are investigated with $O_2$-plasma treatment. The BZO thin films by MOCVD (Metal Organic Chemical Vapor Deposition) are investigated and the samples of $H_2$ post-treated BZO thin film are tested with $O_2$-plasma treatment by plasma treatment system with 13.56 MHz as RIE (Reactive Ion Etching) type. We measured the optical properties and surface morphology of BZO thin film with and without $O_2$-plasma treatment. The optical properties such as transmittance, reflectance and haze are measured with integrating sphere and ellipsometer. This result of the BZO thin film with and without $O_2$-plasma treatment is application to the TCO for solar cells.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.151-156
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• 2012

Reflective polarizers can be used as luminance enhancement films for LCD backlights via the polarization recycling process. The optical performances of a wire grid polarizer (WGP) as a reflective polarizer adopted in edge-lit backlights were investigated by luminance evaluation and a time-domain simulation technique. The results were compared to those of a commercial dielectric multilayer film. The luminance gain factor of WGP was smaller than that of the multilayer film by 18%. This was attributed to a much larger internal loss of WGP due to light absorption by metal wires. The internal losses of both reflective polarizers and the polarization conversion efficiency of the backlight were obtained numerically based on a phenomenological model. The optical performances of WGP were optimized by using a time-domain simulation technique. The luminance gain increased and was found to become comparable to, but slightly less than the case of the dielectric multilayer film with decreasing line width.

• Journal of the Optical Society of Korea
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• v.15 no.1
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• pp.38-43
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• 2011

We have developed a simple model of a bright-room contrast ratio (BRCR) measurement system for plasma display panels (PDPs) adopting a contrast enhancement film (CEF) by using an illumination design tool. Only four model parameters were used, namely, total ambient illumination power delivered by fluorescent lamps, a panel scattering rate, illuminance of PDP white patterns, and the absorption coefficient of a color adjusting film. These parameters were determined by simple optical measurements and matching simulations. The proposed model was employed to predict the BRCR values of four different CEF samples, and the simulated ones were found to be in agreement with measured ones within about 10% relative-error.