• 제목/요약/키워드: Lee Gyu Jun

검색결과 1,651건 처리시간 0.123초

흰쥐 C6 신경교종 세포에서 Venlafaxine 그리고 Dexamethasone 처리가 열충격 단백질 70의 발현에 미치는 영향 (Effects of Venlafaxine and Dexamethasone Treatment on HSP70 Expression in Rat C6 Glioma Cells)

  • 유재학;이준석;양병환;최미란;채영규;김석현;노성원;오동열;최인근
    • 생물정신의학
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    • 제12권2호
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    • pp.136-142
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    • 2005
  • Object:The intracellular action of the antidepressant, venlafaxine, was studied in C6-gliomas using heat shock protein 70(HSP70) immunocytochemistry and HSP70 Western blots because HSP70 is associated with stress and depression. Methods:To examine how the glucocorticoid affects the expression of HSP70 in nerve cells, the rat C6 glioma cell was treated with dexamethasone for 6 hours. In addition, venlafaxine was administered to the experimental groups of C6 glioma cells for 1, 6, 24, and 72 hours each, after which the expression of HSP70 was investigated. Finally, venlafaxine and dexamethasone were simultaneously administered to the experimental groups for 1, 6, 24, and 72 hours, followed by an investigation of the expression of HSP70. Results:The short term(1 hour) venlafaxine treatment significantly increased the level of HSP70 expression. The short term treatment of venlafaxine with dexamethasone also increased the level of HSP70 expression but this reduction was not statistically significant. The long term(72 hours) venlafaxine with dexamethasone treatment significantly reduced the level of HSP70 expression. The long term treatment of venlafaxine also reduced the level of HSP70 expression but this reduction was not statistically significant. Dexamethasone(10uM, 6hours) did not affect the level of HSP70 expression compared with controls. Conclusion:Venlafaxine increases the expression of HSP70 at short term treatment, but prolonged treatment with dexamethasone suppresses the expression of HSP70.

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저소음 청소기 개발 (Low Noise Vacuum Cleaner Design)

  • 주재만;이준화;홍승기;오장근;송화규
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.939-942
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    • 2007
  • Vacuum cleaner is a close life product that can remove various dusts from our surroundings. However well vacuum cleaner clean our environments, many people are looking away from it, due to its loud noise. Its noise causes a big trouble in the usual life, for example, catch calls, TV watching and discussing etc. To reduce these inconveniences, noise reduction methods and systematic design of low noise vacuum cleaner are studied in this paper. At first, sound quality investigation is performed to get the noise level and quality that make people TV watching and catch calls available. Based on the European and domestic customer SQ survey result, sound power, peak noise level and target sound spectrum guideline are studied and introduced. As a second, precise product sound spectrums are designed into each part based on the sound quality result. Fan-motor, brush, mainbody, cyclone spectrums are decided to get the final target sound based on the contribution level. Fan-motor is the major noise source of vacuum cleaner. Specially, its peak sound, RPM peak and BPF Peak, cause the people nervous. To reduce these peak sounds, high rotating impeller and diffuser are focused due to its interaction. A lot of experimental and numerical tests, operation points are investigated and optimization of flow path area between diffusers is performed. As a bagless device, cyclones are one of the major noise sources of vacuum cleaner. To reduce its noise, previous research is used and adopted well. Brush is the most difficult part to reduce noise. Its noise sources are all comes from aero-acoustic phenomena. Numerical analysis helps the understanding of flow structure and pattern, and a lot of experimental test are performed to reduce the noise. Gaps between the carpet and brush are optimized and flow paths are re-designed to lower the noise. Reduction is performed with keeping the cleaning efficiency and handling power together and much reduction of noise is acquired. With all above parts, main-body design is studied. To do a systematic design, configuration design developments technique is introduced from airplane design and evolved with each component design. As a first configuration, fan-motor installation position is investigated and 10 configuration ideas are developed and tested. As a second step, reduced size and compressed configuration candidates are tested and evaluated by a lot of major factor. Noise, power, mass production availability, size, flow path are evaluated together. If noise reduction configuration results in other performance degrade, the noise reduction configuration is ineffective. As a third configuration, cyclones are introduced and the size is reduced one more time and fourth, fifth, sixth, seventh configuration are evolved with size and design image with noise and other performance indexes. Finally we can get a overall much noise level reduction configuration. All above investigations are adopted into vacuum cleaner design and final customer satisfaction tests in Europe are performed. 1st grade sound quality and lowest noise level of bagless vacuum cleaner are achieved.

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상륙에서 추출한 ${\alpha}-spinasterol$의 백혈병세포주(U937) 자멸사 유도 효능 (Effect of ${\alpha}-spinasterol$ Extracted from Phytolacca americanna on the Apoptosis of U937 cell line)

  • 양준석;정상훈;김호;한웅;진재호;정일국;김대근;정승일;정한솔;이광규
    • 동의생리병리학회지
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    • 제21권5호
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    • pp.1108-1117
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    • 2007
  • To investigate the possible mechanism of ${\alpha}-spinasterol$ as a candidate of anti-cancer drug, I examined the effects of ${\alpha}-spinasterol$ on the apoptosis of U937 cells MTT assay, flow cytometric analysis, SDS-polyacrylamide gel electrophoresis, Western blot analysis, and RT-PCR were performed. ${\alpha}-spinasterol$ treatment reduced the cell viablilty of U937 cells in a dose-dependent manner, which was associated with the induction of apoptotic cell death. ${\alpha}-spinasterol$ treatment also reduced the levels of Bcl-xL anti-apoptotic protein expression and increased the levels of caspase-3, p53, pro-apoptotic protein, in U937 cells. After treatment the level of Bcl-xL, anti-apoptotic gene expression was decreased and the level of ICE pro-apoptotic gene expression was increased. These findings suggest that ${\alpha}-spinasterol$ induced the apoptotic cell death via regulation of several growth regulatory gene products. The abbreviations used are: FBS, fetal bovine serum; PBS, phosphate buffered saline; PI, propidium iodide; OD, optical density; DiOC6, 3,3-dihexyloxa carbcyanine iodide; MTT, 3 [4-5-dimethylthiazol-2-yl] -2-diphenyltetrazolium bromide.

AMBIDEXTER 천이노심 설계최적화를 위한 노심관리 알고리즘 개발 (Development of a Core management Algorithm for Optimal Design of AMBIDEXTER Transient Cores)

  • 유극종;신동훈;소순규;이영준;김진성;오세기
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 2004년도 추계학술발표회 발표논문집
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    • pp.99-100
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    • 2004
  • AMBIDEXTER-NEC의 천이노심은 $^{Nat}Th$$^{Nat}U$의 주입만으로 전 출력의 Break-even 노심에 도달하기위한 중간 단계이다. 선행연구에서 수행한 전 출력노심인 평형노심의 핵종수밀도에 도달하기 위해서 평형노심에서의 기저물질, 잠재핵분열성물질, 핵분열물질의 수밀도를 각 SEU-기반, Pu-기반, ADS-기반에서 그대로 유지하여 초기노심을 구성하였다. 또 각 시나리오에 대해 최대첨두출력과 원자로의 안전성을 고려해 Excess Reactivity를 5mk 내에서 초기노심을 결정하였다. 각 노심은 주 핵분열성물질 $^{235}U$, $^{239}Pu$$^{233}U$의 핵반응단면적 특성에 따라 평균 전환율이 각각 0.95, 0.83 및 1 .21 로서 핵연료물질의 적절한 선택만으로도 전환로, 연소로 및 증식로로 설계할 수 있음을 보여준다. 이러한 $Th/^{233}U$, U/Pu 핵연료주기를 사용하는 AMBIDEXTER-NEC 용융염핵연료 원자로의 초기노심에서 시작한 천이노심은 평형노심에장전할 충분한 $^{233}U$ 양을 확보해야 하므로 천이노심의 목표는 평형노심 $^{233}U$의 요구량에 최소한의 기간에 가장 적은 외부주입을 통해 도달하는 것이다. 천이노심에서 임계가 유지되는 AMBIDEXTER-NEC 원자로시스템의 3군 핵종변환 코드인 HELIOS-SQUID-AMBIBURN 체제를 개발하였고 그림 1.에 나타내었다. 이 알고리즘은 각 초기노심 중원소의 미시단면적, 중원소를 제외한 원소들의 거시단면적, 임계도를 만족하는 중성자속 및 외부주입율을 계산하여 SQUID 및 AMBIBURN 입력자료를 제공한다. 또한 일정시간 중원소의 핵종농도, 외부주입율과 중성자속이 일정하다는 가정 하 에 반복수행 하고 SEU-기반과 Pu-기반의 경우에는 각각 핵변환을 거쳐 재순환되는 $^{233}U$$^{239}Pu$의 양을 바로 주입하는 최대재순환 경우와 평형노심 요구 장전량에 이를 때까지 시설 내 저장하는 최소재순환 경우로 상황을 모사하였다. 그림 2 는 각 시나리오별 초기노심에서부터 200FPD까지 단위 용융염 체적당 $^{233}U$의 수밀도 시간변화를 나타낸 것이다. 그림을 보면 50일 이후부터는 수밀도의 변화가 일정한 기울기를 보이고 있고 재처리공정에서 $^{233}Pa$를 분리하는 최소재순환의 경우에는 최대재순환보다 2-3%정도에 지나지않아 그림에서 나타내지않았다. SEU-기반 및 Pu-기반에서 $^{233}U$의 증가율이 각각 2.54E+13, 2.81E+13 #/cc/d 로 Pu 기반이 조금 더 큰 증가율을 나타내고 있지만 평형노심 농도 1.04E+20 #/cc/d 에 도달하기 위해서는 두 경우 모두 매우 긴 시간이 걸릴 것을 예상할 수 있다. 요컨대 250MWth AMBIDEXTER-NEC가 평형노심을 이루기 위해 필요로 하는 $^{233}U$을 생산하는데 제안한 SEU-기반, Pu-기반 시나리오는 천이노심주기기간이 전형적인 원자로 수명 3-40년 보다 매우 큰 것으로 나타났다. 따라서 장전될 $^{233}U$의 확보를 위한 최적옵션은 초기노심부터 ADS와 같은 외부생산시설로부터 전량을 공급 받아 운전하는 것이라 판단된다.

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Ginsenoside Production and Morphological Characterization of Wild Ginseng (Panax ginseng Meyer) Mutant Lines Induced by γ-irradiation (60Co) of Adventitious Roots

  • Zhang, Jun-Ying;Bae, Tae-Woong;Boo, Kyung-Hwan;Sun, Hyeon-Jin;Song, In-Ja;Pham, Chi-Hoa;Ganesan, Markkandan;Yang, Dae-Hwa;Kang, Hong-Gyu;Ko, Suk-Min;Riu, Key-Zung;Lim, Pyung-Ok;Lee, Hyo-Yeon
    • Journal of Ginseng Research
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    • 제35권3호
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    • pp.283-293
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    • 2011
  • With the purpose of improving ginsenoside content in adventitious root cultures of Korean wild ginseng (Panax ginseng Meyer), the roots were treated with different dosages of ${\gamma}$-ray (5, 10, 25, 50, 75, 100, and 200 Gy). The growth of adventitious roots was inhibited at over 100 Gy. The irradiated adventitious roots showed significant variation in the morphological parameters and crude saponin content at 50 to100 Gy. Therefore, four mutant cell lines out of the propagation of 35 cell lines treated with 50 Gy and 100 Gy were selected on the basis of phenotypic morphology and crude saponin contents relative to the wild type control. The contents of 7 major ginsenosides ($Rg_1$, Re, $Rb_1$, $Rb_2$, Rc, Rf, and Rd) were determined for cell lines 1 and 3 from 100 Gy and lines 2 and 4 from 50 Gy treatments. Cell line 2 showed more secondary roots, longer length and superior growth rate than the root controls in flasks and bioreactors. Cell line 1 showed larger average diameter and the growth rate in the bioreactor was comparable with that of the control but greater in the flask cultured roots. Cell lines 1 and 2, especially the former, showed much more ginsenoside contents than the control in flasks and bioreactors. Therefore, we chose cell line 1 for further study of ginsenoside contents. The crude saponin content of line 1 in flask and bioreactor cultures increased by 1.4 and 1.8-fold, respectively, compared to the control. Total contents of 7 ginsenoside types ($Rg_1$, Re, $Rb_1$, $Rb_2$, Rc, Rf, and Rd) increased by 1.8 and 2.3-fold, respectively compared to the control. Crude saponin and ginsenoside contents in the bioreactor culture increased by about 1.4-fold compared to that the flask culture.

Assembly processes of moss and lichen community with snow melting at the coastal region of the Barton Peninsula, maritime Antarctic

  • Kim, Seok Cheol;Kim, Jun Seok;Hong, Bo Ram;Hong, Soon Gyu;Kim, Ji Hee;Lee, Kyu Song
    • Journal of Ecology and Environment
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    • 제40권1호
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    • pp.55-65
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    • 2016
  • Background: In this article, it was analyzed how snow melting affects the assembly of lichen and moss communities in a small area of the coastal region of Barton Peninsula, which is in maritime Antarctic. In the small area, even though there is a huge gap of difference of the environment between the snow-filled area and snow-melt one, the latter did not have distinctive environmental gradients. Results: Depending on the snow melting time, coverage and species diversity of lichens and mosses tend to increase remarkably. For species with significant changes depending on the snow-covered period, there are Andreaea regularis, crustose lichens, Placopsis contortuplicata, Usnea aurantiaco-atra, and snow algae. In this area, the process of vegetation assembly process has shown the directional development in the order of snow algae${\rightarrow}$crustose, lichen sub-formation${\rightarrow}$fruticose lichen, moss cushion sub-formation (Andreaea sociation)${\rightarrow}$fruticose lichen, and moss cushion sub-formation (Usnea sociation), according to the order of snow melting. These directional development stages are shown in gradual change in small area with the snow melting phenomena. However, in the snow-free area, where water is sufficiently supplied, it is expected that moss carpet sub-formation (Sanionia sociation) will be developed. Vegetation development in the small area with the snow melting phenomena, depending on differences of resistance on snow kill and moisture settled by species in according to the time of snow melting, tolerance model to form community is followed. Conclusions: The research results explain the development of vegetation in the Antarctic tundra and its spatial distribution according to the period for growth of lichens and mosses in the summer time by differences of snow melting in the small area. In the future, if research for the community development process in a large scale will be done, it will be helpful to figure out temporal and spatial dynamic of vegetation in the Antarctic tundra where snow and glaciers melt rapidly due to climatic warming.

상황인지 센서를 활용한 지능형 산불 이동 예측 및 탐지 알고리즘에 관한 연구 (A Study on forest fires Prediction and Detection Algorithm using Intelligent Context-awareness sensor)

  • 김형준;신규영;우병훈;구남경;장경식;이강환
    • 한국정보통신학회논문지
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    • 제19권6호
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    • pp.1506-1514
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    • 2015
  • 본 논문에서는 상황 인식 센서를 활용한 화재 발생 예측 및 탐지 방법을 제안한다. 기존 기상 및 비전 센서 기반의 산불 방재 시스템의 경우 카메라 센서로 획득한 영상을 조명변화에 강인한 색상공간인 HSI(Hue, Saturation, Intensity) 모형으로 변환시켜 처리하여 산불영역에 대한 특징을 추출하고 있다. 그러나 이 경우 단일 카메라 센서가 넓은 범위에 화재를 감지하기 때문에 넓은 범위의 화재가 발생하기 전까지는 화재발생을 감지하는데 어려움이 있다. 따라서 본 논문에서는 센서를 활용하여 실시간으로 온도, 습도, Co2, 불꽃유무정보를 습득하여 화재를 판단하는 알고리즘과 그에 따른 화재의 확산경로와 속도예측 및 안전구역 확보 알고리즘을 제안한다. 제안된 알고리즘은 복합적 인 상황에 따라 부여된 가중치를 수집된 데이터에 부여하여 화재를 판단하고, 시간에 따른 상황인식 분석을 통해 화재 이동방향과 속도를 예측하여 안전구역을 확보하는 기법이다.

표고균이 접종된 수입 톱밥 배지에서 중금속과 잔류농약 조사 (Investigation of Heavy Metals and Residual Pesticides from Imported Oak Mushroom Culture-inoculated Sawdust Media)

  • 김준영;권혁우;고한규;현민우;이찬중;김성환
    • 한국버섯학회지
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    • 제15권4호
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    • pp.202-205
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    • 2017
  • 국내 안전 버섯생산을 위해서 수입된 표고균이 접종된 표고배지에서 중금속과 잔류농약의 존재 위험성을 두고 우려가 있어 왔다. 버섯의 안전 생산을 위해서는 우려되는 위험성에 대해 건전한 논의를 위한 기초 자료가 필요하다. 이에따라 본 연구에서는 2013년과 2015년 사이 중국 6개 지역에서 수입된 표고균이 접종된 톱밥배지에서 중금속과 잔류농약 존재여부를 알고자 분석을 수행하였다. 납, 비소, 크롬, 수은, 카드뮴 중에서 비소, 크롬, 수은은 검출되지 않았다. 납은 길림, 산동, 텐진, 요녕 지역에서 수입된 표고톱밥배지에서 검출되었으며 검출수준은 1.7 에서 3.2 mg/kg 이었다. 카드뮴은 산동과 요녕 지역에서 검출되었고 검출수준은 0.028 to 0.037 mg/kg 이었다. 잔류농약은 모든 시료에서 불검출되었다.

Analysis of Surface Plasmon Resonance on Periodic Metal Hole Array by Diffraction Orders

  • 황정우;윤수진;강상우;노삼규;이상준
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.176-177
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    • 2013
  • Surface plasmon polaritons (SPPs) have attracted the attention of scientists and engineers involved in a wide area of research, microscopy, diagnostics and sensing. SPPs are waves that propagate along the surface of a conductor, usually metals. These are essentially light waves that are trapped on the surface because of their interaction with the free electrons of conductor. In this interaction, the free electrons respond collectively by oscillating in resonance with the light wave. The resonant interaction between the surface charge oscillation and the electromagnetic field of the light constitutes the SPPs and gives rise to its unique properties. In this papers, we studied theoretical and experimental extraordinary transmittance (T) and reflectance (R) of 2 dimensional metal hole array (2D-MHA) on GaAs in consideration of the diffraction orders. The 2d-MHAs was fabricated using ultra-violet photolithography, electron-beam evaporation and standard lift-off process with pitches ranging from 1.8 to $3.2{\mu}m$ and diameter of half of pitch, and was deposited 5-nm thick layer of titanium (Ti) as an adhesion layer and 50-nm thick layer of gold (Au) on the semiinsulating GaAs substrate. We employed both the commercial software (CST Microwave Studio: Computer Simulation Technology GmbH, Darmstadt, Germany) based on a finite integration technique (FIT) and a rigorous coupled wave analysis (RCWA) to calculate transmittance and reflectance. The transmittance was measured at a normal incident, and the reflectance was measured at variable incident angle of range between $30^{\circ}{\sim}80^{\circ}$ with a Nicolet Fourier transmission infrared (FTIR) spectrometer with a KBr beam splitter and a MCT detector. For MHAs of pitch (P), the peaks ${\lambda}$ max in the normal incidence transmittance spectra can be indentified approximately from SP dispersion relation, that is frequency-dependent SP wave vector (ksp). Shown in Fig. 1 is the transmission of P=2.2 um sample at normal incidence. We attribute the observation to be a result of FTIR system may be able to collect the transmitted light with higher diffraction order than 0th order. This is confirmed by calculations: for the MHAs, diffraction efficiency in (0, 0) diffracted orders is lower than in the (${\pm}x$, ${\pm}y$) diffracted orders. To further investigate the result, we calculated the angular dependent transmission of P=2.2 um sample (Fig. 2). The incident angle varies from 30o to 70o with a 10o increment. We also found the splitting character on reflectance measurement. The splitting effect is considered a results of SPPs assisted diffraction process by oblique incidence.

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Analysis of Subwavelength Metal Hole Array Structure for the Enhancement of Quantum Dot Infrared Photodetectors

  • 하재두;황정우;강상우;노삼규;이상준;김종수
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.334-334
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    • 2013
  • In the past decade, the infrared detectors based on intersubband transition in quantum dots (QDs) have attracted much attention due to lower dark currents and increased lifetimes, which are in turn due a three-dimensional confinement and a reduction of scattering, respectively. In parallel, focal plane array development for infrared imaging has proceeded from the first to third generations (linear arrays, 2D arrays for staring systems, and large format with enhanced capabilities, respectively). For a step further towards the next generation of FPAs, it is envisioned that a two-dimensional metal hole array (2D-MHA) structures will improve the FPA structure by enhancing the coupling to photodetectors via local field engineering, and will enable wavelength filtering. In regard to the improved performance at certain wavelengths, it is worth pointing out the structural difference between previous 2D-MHA integrated front-illuminated single pixel devices and back-illuminated devices. Apart from the pixel linear dimension, it is a distinct difference that there is a metal cladding (composed of a number of metals for ohmic contact and the read-out integrated circuit hybridization) in the FPA between the heavily doped gallium arsenide used as the contact layer and the ROIC; on the contrary, the front-illuminated single pixel device consists of two heavily doped contact layers separated by the QD-absorber on a semi-infinite GaAs substrate. This paper is focused on analyzing the impact of a two dimensional metal hole array structure integrated to the back-illuminated quantum dots-in-a-well (DWELL) infrared photodetectors. The metal hole array consisting of subwavelength-circular holes penetrating gold layer (2DAu-CHA) provides the enhanced responsivity of DWELL infrared photodetector at certain wavelengths. The performance of 2D-Au-CHA is investigated by calculating the absorption of active layer in the DWELL structure using a finite integration technique. Simulation results show the enhanced electric fields (thereby increasing the absorption in the active layer) resulting from a surface plasmon, a guided mode, and Fabry-Perot resonances. Simulation method accomplished in this paper provides a generalized approach to optimize the design of any type of couplers integrated to infrared photodetectors.

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