a 한국과학기술연구원 나노소자연구센터, 서울 136-791 b 고려대학교 전자공학과, 서울 136-701 c 동의대학교 정보통신공학과, 부산 614-714 (2009년 7월 9일 받음, 2009년 7월 22일 수정, 2009년 7월 23일 확정) Migration Enhanced Molecular Beam Epitaxy를 통해 성장한 GaAs 기반 1300 nm 파장대역 InAs 양자점 레이저 다이오드 의 발진 특성을 연구하였다. 펄스 및 상온 연속 동작에서 전류 주입 및 동작 온도 변화에 따른 L-I 특성과 발진 스펙트럼 측정 을 통해 바닥준위(1302 nm)에서 여기준위(1206 nm)로의 발진 파장의 전환을 관찰하였으며 이는 양자점 바닥준위 이득의 포 화로 이해된다. 상온 펄스 동작시 문턱전류 밀도는 92 A/cm 2 , 발진 파장은 1311 nm이며, 상온 연속 동작시 문턱전류 밀도는 247 A/cm 2 , 발진 파장은 1320 nm이다. 주제어 : GaAs, In(Ga)As, 양자점 레이저 다이오드, 분자선 에피택시, Migration enhanced epitaxy ≪Research Paper-Special Topics≫ We have investigated the lasing characteristics of GaAs-based 1300 nm wavelength region InAs Quantum Dot Laser Diode grown by Migration Enhanced Molecular Beam Epitaxy. Under a pulsed and CW operation, we observed the state switching of lasing wavelength from ground state (1302 nm) to excited state (1206 nm) due to the gain saturation of ground state. Under a pulsed operation, J th =92 A/cm 2 , λ L =1311 nm and under a CW operation, J th =247 A/cm 2 , λ L =1320 nm.
Ambient particulate matters(PM10 and PM2.5) were investigated at GNTECH university in Jinju city. Samples were collected using a dichotomous sampler(series 240, Andersen Corp.) and a TEOM(Tapered Element Oscillating Microbalance) monitor period from November 2012 to October 2013. For the dichotomous sampler measurements, daily 24-h integrated PM2.5 and PM10-2.5 ambient air samples were collected at a total flow rate of 16.7 L /min. For the TEOM monitor measurements, daily 1-h integrated PM10 ambient air samples were collected at a flow rate of 16.7 L /min. The annual average concentrations of PM10-2.5 and PM2.5 by a dichotomous sampler were 10.0±6.1 μg/m 3 and 22.6±9.3 μg/m 3 , respectively. And PM10 concentration by dichotomous sampler were similar to TEOM monitor by 32.7±12.9 μg/m 3 and 31.7±11.3 μg/m 3 , respectively. And good correlation (R 2 =0.964) between the two methods was observed. The annual average of PM2.5/PM10 ratio was 0.70±0.12.
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