• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.2020-2021
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• 2004

Distributed optical feedback by gain coupling in V-groove quantum-wire lasers is investigated using InGaAs/AlGaAs active materials grown by metalorganic chemical vapor deposition (MOCVD). In order to avoid grating overgrowth during the fabrication of DFB structures, a newly developed constant MOCVD growth method is employed. Gain anisotropy in emission spectra near Bragg wavelength, resulting from optical feedback along the DFB direction, is clearly observed at room temperature.

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.166-167
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• 2005

The doping technique has been well known as method to get various emission color by choosing appropriate fluorescent dyes as a dopant. Usually, red emission of OLED device based on Alg$_{3}$ doped with DCM and rubrene is fabricated. Result that fabricate OLED device was manufactured by various doping density, we looked for the doping ratio of highest luminescent efficiency.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.5-6
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• 1989

The overall design of the optical isolator system is prepared for the 1 TW Nd pulse laser. Two pockels cell optical switches are employed to suppress the amplified spontaneous emission and the backward reflection. The role of two Farady rotators is to protect the laser system from the light amplified after back reflection. One saturable absorber dye and one liquid crystal polarizer/isolator will also serve as optical isolator.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.361-362
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• 2012

We summarize the progress on the rest-frame optical spectroscopy of quasars at 3$2.5-5{\mu}m$. This spectral window has been utilized for detecting redshifted $H{\alpha}$ emission lines of our high redshift subsample of quasars. From the calculated emission line widths and luminosities we measured supermassive black hole masses using well calibrated optical mass estimators. Science topics regarding optical based black hole masses at high-z are discussed.

• Smart Structures and Systems
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• v.18 no.3
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• pp.471-484
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• 2016

Optical fiber sensors have been proven that they have the potential to detect high-frequency ultrasonic signals, in structural health monitoring field which generally refers to acoustic emission signals from active structural damages and guided waves excited by ultrasonic actuators and propagating in waveguide. In this work, the sensing properties of optical fiber sensors based on Mach-Zehnder interferometer were investigated in the metal plate. Analytical formulas were conducted first to explore the parameters affecting its sensing performances. Due to the simple and definable frequency component, the Lamb wave excited by the piezoelectric wafer was employed to study the sensitivity of the proposed optical fiber sensors with respect to the frequency, rather than the acoustic emission signals. In the experiments, according to above investigations, spiral shape optical fiber sensors with different size were selected to increase their sensitivity. Lamb waves were excited by a circular piezoelectric wafer, while another piezoelectric wafer was used to compare their voltage responses. Furthermore, by changing the excitation frequency, the tuning frequency characteristic of the proposed optical fiber sensor was also investigated experimentally.

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.122-123
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• 2005

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.66-67
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.304-305
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.290-291
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• 2005

We have presented a comprehensive effective-mass Hamiltonian for strained Wurtzite semiconductors using k${\cdot}$p method and Kane's model. This theoretical groundwork provides a foundation for investigating the electrical and optical properties of wurtzite strained quantum-well lasers.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.105-110
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• 2000

Biosensors consist principally of two basic components, receptor and transducer. The transducer part of the sensor serves the signal transfer from the output domain of the recognition system. Optical method of transducer have many benefits, based on phenomena like emission and absorption. This paper will review the methode of optical transduction in brief and out some new development.