• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.83-85
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• 2004

MOCVD(metalorganic chemical vapor deposition)에 의해 성장된 InGaAs/AlGaAs 물질을 이용하여 V-형 양자선 (V-groove quantum-wire) 어레이(array) 구조에서 이득 결합(gain-coupling)에 의한 분포 광귀환(distributed optical feedback) 특성을 조사하였다. 분포 귀환형 (distributed feedback, DFB) 구조를 제작하는 동안 격자 재성장(grating overgrowth)을 피하기 위하여, 새롭게 개발된 constant MOCVD 성장 방법을 적용하였고, Bragg 파장에서 DFB 방향으로 광귀환의 결과인 스펙트럼의 이득 이방성(gain asymmetry)을 실험적으로 관찰하였다.

• 한국진공학회지
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• 제15권3호
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• pp.294-300
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• 2006

금속유기화학증착기 (metal-organic chemical vapor deposition)를 이용하여 분포귀환형 (distributed feed back) InP/InGaAs/InP 회절격자 구조를 제작하고 원자력간현미경 (atomic force microscopy)과 주사전자현미경 (scanning electron microscopy) 실험을 통해 표면 및 단면을 분석하였다. 그 위에 분자선증착기(molecular beam epitaxy)법을 이용하여 자발형성 (self-assembled) InAs/InAlGaAs 양자점 (quantum dot)을 성장하고, 광학적 특성을 온도변화 광여기 발광 (photoluminescence)으로 회절격자 구조 없이 성장한 양자점 시료와 비교 분석하였다. 회절격자의 간격 대비 폭의 비가 약 30%인 InP/InGaAs/InP 회절격자가 제작되었으며, 그 위에 성장된 양자점의 경우 상온 파장이 1605 nm에서 PL이 관찰되었다. 이는 회절격자 없이 같은 조건에서 성장된 시료의 상온 파장인 1587 nm 보다 장파장에서 발광하였으며, 회절격자의 영향으로 양자점 크기가 변하였음을 조사하였다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 춘계학술대회
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• pp.88-91
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• 1994

We develope a assistant system of foot pressure distribution for improvement gait Pattern, adapted working speed, and minimitation of muscle fatigue of the sensory feedback type FES system(SEFES). This measurement system consist of mat type pressure sensor with piezo electric films. The pressure data signal multiflexed input scanning method processed A/D conversion after two step amplify and integrate. Matrix sensor interface to PC for pseudo color display by level of Pressure distribution data. This measurement system clinically evaluated in hemiplegic patients. It has produced acceptable results with optimal location of the food sensor's pressure point and avoid the muscle fatigue.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.96-99
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• 2005

As the demand of internet networks using backbone communication systems recently increased, the researches on the high-speed wideband optical communication systems are required. For high-speed optical communication systems, asymmetric sampled grating distributed feedback laser diodes (DFB-LDs) are developed and the reliability of DFB-LDs is examined. The reliability of DFB-LDs is performed by monitoring I-V and L-I characteristics and two degradation phenomena related to the electrical characteristics of LDs are observed during the life tests. The first degradation phenomenon by increasing the reverse current is considered as a formation of leakage current path enough to prevent lasing operation in lateral blocking layer near active region of lasers. The second degradation phenomenon by decreasing the forward current is considered as activation of non-radiative Auger recombination process by thermal energy and the second degradation phenomenon is recovered after the off-test period at room temperature Eventually, evaluating the reliability of DFB LDs can allow us to improved the manufacturability in high-volume manufacturing.

• 반도체디스플레이기술학회지
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• 제10권4호
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• pp.131-138
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• 2011

We fabricated distributed feedback InGaAsP/InP laser diodes for optical fiber communication module and characterized the lasing properties in continuous wave operation. The active layer of 7-period InGaAsP(1.127 eV)/InGaAsP(0.954 eV) multi-quantum well structure was grown by the metal-organic chemical vapor deposition. The grating for waveguide was also fabricated by the implementation of the Mach-Zehender holographic method of two laser beams interference of He- Cd laser and the fabricated laser diode has the dimension of the laser length of $400{\mu}m$ and the ridge width of $1.2{\mu}m$. The laser diode shows the threshold current of 3.59 mA, the threshold voltage of 1.059 V. For the room-temperature operation with the current of 13.54 mA and the voltage of 1.12 V, the peak wavelength is about 1309.70 nm and optical power is 13.254 mW.