• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.80-81
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• 2002

편광 방향이 단일 모드의 유지되는 광섬유와 파장이 780nm인 반도체 레이저를 사용하여 간결한 구조의 beam scanning 타입의 공초점 현미경을 구성하였다. 공초점 현미경은 세포내의 생명 현상을 보다 잘 이해 할 수 있는 장비이기 때문에 기존의 현미경으로는 연구할 수 없던 생명현상을 연구할 수 있도록 여러 가지 강력한 연구수단을 제공하고 있다 살아 움직이는 생명체를 관찰할 수 있는 공초점 현미경에서 중요한 것은 속도와 투과 깊이이고, 장기의 표면을 관찰하기 위해서는 크기가 작아야 한다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.100-101
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.136-137
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• 2004

• Proceedings of the KAIS Fall Conference
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• 2004.06a
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• pp.247-249
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• 2004

본 논문에서는 격자구조의 유전체에 수직으로 입사된 전자기파의 산란, 투과 특성을 얇은 위상 막 근사화 이론을 이용하여 분석하였다. 위상 막 근사화 이론은 격자구조가 입사되는 전자기파의 위상 변화만을 주는 것으로 간주하는 것으로 이를 이용하여 격자구조를 통과한 직후인 근거리 필드 분포를 TE 모드에서 계산하였다. 기존의 제시된 이론에 비해 비교적 간단하고 빠르게 산란 필드를 분석할 수 있다.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.132-133
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• 2003

편광 방향이 단일 모드로 유지되는 광섬유와 파장이 780nm인 반도체 레이저를 사용하여 간결한 구조의 beam scanning 타입의 비편광 공초점 현미경을 구성하였다. 일반적인 공초점 현미경은 세포내의 생명 현상을 보다 잘 이해 할 수 있는 장비이기 때문에 기존의 현미경으로는 연구할 수 없던 생명현상을 연구할 수 있도록 여러 가지 강력한 연구수단을 제공하고 있다. 살아 움직이는 생명체를 관찰할 수 있는 공초점 현미경에서 중요한 것은 속도와 투과 깊이이고, 장기의 표면을 관찰하기 위해서는 크기가 작아야 한다. (중략)

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.5
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• pp.495-503
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• 1997

In this paper, the E-polarized electromagnetic scattering problems by a resistive strip grating with tapered resistivity on 3 dielectric layers are analyzed to find out the effects for the tapered resistivity of resistive strip and the relative permittivity and thickness of 3 die- lectric layers by applying the Fourier-Galerkin moment methods. The induced surface current density is expanded in a series of Jacobi-polynomial ${P^{(\chi,\beta)}}_p$(.) of the order $\alpha$= 0 and $\beta$=1 as a kind of orthogonal polyomians, and the tapered resistivity assumes to vary linearly from 0 at one edge to finite resistivity at the other edge. The normalized reflected and transmitted powers are obtained by varying the tapered resistivity and the relative permittivity and thickness of dielectric layers. The sharp variation points are observed when the higher order modes are transferred between propagating and evanescent modes, and in general the local minimum positions occur at less grating period for the more relative permittivity of dielectric layers. It should be noted that the patterns of the normalized reflected and transmitted powers for the tapered resistivity are very much different from those of the uniform resistivity and perfectly conducting cases. The proposed method of this paper cna solve the scattering problems for the tapered resistive, uniform resistive, and PEC strip cases.

• Membrane Journal
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• v.14 no.1
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• pp.75-84
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• 2004

In this study, we present a noble study far membrane transport models using chlorine resistance of polyamide RO membranes. Membrane transport mechanism is investigated by the comparison of membrane permeation performance under the continuous and Intermittent operation modes with mixed feed solution containing NaOCl and NaCl. Analysis of permeation performance indicates that solution-diffusion model and preferential adsorption-capillary flow model are relatively efficient according to operation mode. Under the continuous flow state, mass transfer depends on preferential adsorption-capillary flow model rather than solution-diffusion model. On the other hand, it prefers solution-diffusion model to preferential adsorption-capillary flow model under the stationary state. SEM images of NaOCl treated membrane surfaces strongly support these conclusions. These surface images reveal that NaOCl treated membrane in continuous operation mode exhibits ridge and valley structure in some fraction of the surface area, whereas that in intermittent operation mode shows surface degradation entirely.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.425-433
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• 2012

Purpose: Basic design of virtual colored overlay, film overlay, colored lenses and colored glasses for people with Scotopic Sensitivity Syndrome. Methods: I calculated sRGB and RGB values of the overlays from measured data. I evaluated the relationship between the combinational chromaticities composed of Galaxy Tab white background and film overlays and the chromaticities of pure film overlays. Results: Implementable sRGB and RGB values of the overlays is calculated. The chromaticities of film overlays are different from them with white paper background and them with Galaxy Tab's white background, but showed a certain relationship between them. Light transmittances of Intuitive Overlay are the most (59%-79%) among them and average light reflectance of Reading Ruler is least(8%). Conclusions: The sRGB values and the RGB values are directly applicable to implement assistive tools and the light transmittances are used to calculate ${\alpha}$, transparency of virtual overlay in IT devices. It is recommended to consider the chromaticity of white color in implementing virtual colored overlay in the case which the chromaticity is considerably different to theoretical chromaticity of white color.

• Journal of the Korean Society for Nondestructive Testing
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• v.37 no.1
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• pp.1-6
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• 2017

In this study, a terahertz time domain spectroscopy (THz-TDS) imaging technique was used to measure doping concentration and physical properties (such as refractive index and permittivity) of the doped silicon (Si) wafers. The transmission and reflection modes with an incidence angle of $30^{\circ}$ were employed to determine the physical properties of the doped Si wafers. The doping concentrations of the prepared Si wafers were varied from $10^{14}$ to $10^{18}$ in both N-type and P-type cases. Finally, the correlation between the doping concentration and the power of the THz wave was determined by measuring the powers of the transmitted and reflected THz waves of the doped Si wafers. Additionally, the doped thickness, the refractive index, and permittivity of each doped Si wafer were calculated using the THz time domain waveform. The results indicate that the THz-TDS imaging technique is potentially a promising technique to measure the doping concentration as well as other optical properties (such as the refractive index and permittivity) of the doped Si wafer.

• Korean Journal of Optics and Photonics
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• v.3 no.1
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• pp.27-36
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• 1992

Frequency modulation spectroscopy of the super-cavity, of which finesse is app. 40,000 has been demonstrated by using a sigle mode He-Ne laser. In-phase and quardrature components of frequency modulation signals (FM signal) were obtained by using the 1.5 MHz-driven-electrooptic phase modulator. The vector locus of the FM signa in the phase space, which is consisted of in-phase and quardrature components of the FM signal, was observed and analyzed for the dependence of FM signal upon the phase of the reference signal of a phase-sensitive-detector. According to rotating the phase of the reference signal, the vector locus was observed to rotate with the same phase angle as the reference signal. The in-phase component of the FM signals will be used to stabilize the frequency of the He-Ne laser to the resonant frequency of the super-cavity.