• Journal of the Optical Society of Korea
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• v.10 no.1
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• pp.11-15
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• 2006

We have proposed and theoretically verified an optical regenerator using a single semi-reflective semiconductor optical amplifier (SR-SOA). To explain the operation characteristics and the operation condition of the proposed opticalregenerator, the simplified gain model for the SR-SOA is introduced and confirmed by comparing the result of the SOA simulation based on the transfer matrix method (TMM). The simulation results show that both extinction ratio (ER) enhancement and signal amplification can be achieved in the proposed regenerator.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.193-198
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• 2000

Near-field recording NFR), advanced optical storage technology, relies on maintaining a small gap between the optical head and the media. This can be accomplished by utilizing the flying optical head concept as in the magnetic recording. In this research, slider/suspension system and plastic disk are tested for their head/disk interface performance. CSS tests are conducted to monitor the frictional and flying characteristics of sliders.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.222-223
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• 2003

The optical gain characteristics of 1550nm traveling-wave semiconductor optical amplifiers are analyzed experimentally and theoretically. The result shows that there is an optimum active layer thickness for high saturation output power.

• Current Optics and Photonics
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• v.3 no.5
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• pp.374-381
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• 2019

This study examined a method for designing the optical cavity of a non-dispersive infrared gas detector. The infrared gas detector requires an optical cavity design to lengthen the ray path. However, the optical cavity with multiple reflecting surfaces has off-axis aberration due to the characteristics of the reflecting optical system. The rays were parallelized by using the off-axis parabolic mirror to easily increase the ray path and eliminate off-axis aberration so that the rays are admitted to the effective area of the infrared detector uniformly. A prototype of an infrared gas detector was produced with the designed optical cavity to confirm the performance.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.112-114
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• 1990

A method for fabrication of holographic optical elements (HOE) using dichromated gelatin (DGG) as a recording material is presented. we describe the holographic properties of the DGG and the processing techniques. Holographic characteristics of the DGG including exposure characteristics, diffraction efficiency and angular sensitivity are also discussed. The diffraction efficiency of the obtained holographic grating is about 84%.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.10
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• pp.35-42
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• 1995

In this paper the driving-condition-dependent optical transmission characteristics of an STN LCD are studied. The optical transmission properties are measured for the applied voltage waveform is varied. Also, the optimum ranges of the M signal frequency and the frame frequency are investigated. An LCD is modeled by the equivalent circuit to study the effect of the parameter variation on the frequency response.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.6
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• pp.840-845
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• 1986

In this Part II of the paper, we evaluated the fabrication error and dividing characteristics for the opticalfilters proposed in the Part I. Furthermore, we propose an integrated optical filter with a new function that can eliminate the fabdrication error. The fabrication method and filtering characteristics have been tested by experiments, thereby confirming the validity of the design theory.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.118-124
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• 2016

The shape and location of the cutoff shield in a projection-type headlight system were optimized by a ray-tracing technique. A shield based on a Petsval surface showed better cutoff characteristics than a flat or cylindrical shield, such as a sharp intensity gradient and less color separation at the cutoff line. Adjustment of the shield’s location between the reflector and the aspheric lens further improved its cutoff characteristics.

• Journal of Biosystems Engineering
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• v.19 no.3
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• pp.247-257
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• 1994

Optical properties of the tobacco leaves were determined. Surface colors and reflectance characteristics of the flue-cured variety and the Burley variety with thin and thick leaves were measured. Color was measured by CIE colorimeter and reflectance was measured with a laboratory built reflectance meter utilizing optical bandpass filters whose center wavelengths are from 400 to 700 nm at intervals of 50 nm. The resulting data indicated that the measured color and reflectance would be useful in inspecting tobacco. However no single optical data could be used to successfully grade tobacco leaves.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.101-104
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• 2007

We propose a novel optical configuration for transmissive and reflective mode in the IPS LC cell to improve the viewing angle characteristics in a diagonal direction. The optical design was performed on a Poincar$\dot{e}$ sphere. From the calculation, we confirmed that the proposed configuration provides excellent viewing angle characteristics.