http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
폴리스티렌 나노 비드를 이용한 플라즈모닉 나노 구조체의 광학 특성
김두근,정병규,김홍승,김태룡,김선훈,기현철,김태언,신재철,최영완,Kim, Doo Gun,Jung, Byung Gue,Kim, Hong-Seung,Kim, Tae-Ryong,Kim, Seon-Hoon,Ki, Hyun-Chul,Kim, Tae-Un,Shin, Jae Cheol,Choi, Young-Wan 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.4
We proposed and demonstrated the double layered metallic nano-hole structure using polystyrene beads process to enhance the sensitivity of surface plasmon resonance (SPR). The double layered SPR structures are calculated using the finite-difference time-domain (FDTD) method for the width, thickness, and period of the metallic nano-hole structures. The thickness of the metal film and the metallic nano-hole is 30 and 20 nm in the 214 nm wide nano-hole size, respectively. The double layered SPR structures are fabricated with monolayer polystyrene beads of 420 nm wide. The sensitivities of the conventional SPR sensor and the double layered SPR sensor are obtained to 42.2 and 52.1 degree/RIU, respectively.
김두근,김홍승,오금윤,김선훈,기현철,김태언,김회종,최영완,Kim, Doo Gun,Kim, Hong-Seung,Oh, Geum-Yoon,Kim, Seon-Hoon,Ki, Hyun-Chul,Kim, Tae-Un,Kim, Hwe Jong,Ma, Ping,Hafner, Christian,Choi, Young-Wan 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.3
We have investigated the optical properties of plamonic waveguide with tapered structure based on InP material for photonic integrated circuit(PIC). The proposed plasmonic waveguide is covered with the Ag thin film to generate the plasmonic wave on metallic interface. The optical characteristics of plasmonic waveguide were calculated using the three-dimensional finite-difference time-domain method. The plasmonic waveguide was fabricated with the lengths of 2 to $10{\mu}m$ and the widths of 400 to 700 nm, respectively. The plasmonic mode and optical loss were measured. The optimum plasmonic length is $10{\mu}m$ and widths are 600 and 700 nm in the fabricated waveguide. This plasmonic waveguide can be directly integrated with other conventional optical devices and can be essential building blocks of PIC.
김두근,김형수,정성재,최영완,이석,우덕하,전영민,유병길,Kim, Doo-Gun,Kim, Hyung-Soo,Jung, Sung-Jae,Choi, Young-Wan,Lee, Seok,Woo, Deok-Ha,Jhon, Young-Min,Yu, Byung-Geel 한국광학회 2002 한국광학회지 Vol.13 No.2
본 연구에서는 광통신 시스템에 응용할 수 있는 장파장용 광 싸이리스터(optcal thyristor)를 제안하고, 소자를 제작하여 그 특성을 측정 분석하였다. 발광과 수광의 기능을 수행하는 광 싸이리스터는 광 네트워크 구성의 핵심 소자로서 충분한 스위칭 전압이 요구되는데, 단일 광 싸이리스터에서 충분한 스위칭 전압 4.03(V)와 홀딩 전압(holding voltage) 1.77(V)를 얻었다. 또한 입력 전류에 따른 수광에 필요한 충분한 광량을 얻을 수 있었고, 입사 광에 따른 비선형 I-V특성의 변화량을 확인 할 수 있었다. 실험적으로 얻어진 장파장용 DOT의 비선형적 특성은 일정한 진폭을 유지 시켜주는 광 하드 리미터(optical hard-limiter), ATM패킷 헤더 프로세싱을 위한 광 ATM 패킷 스위cld, 파장 분할 다중화(WDM) 광전송 시스템에서 파장 라우팅을 위한 파장 변환기 등의 많은 광통신 용용 분야에 적용할 수 있다. 1.55${\mu}{\textrm}{m}$ PnpN optical thyristor as a smart optical switch has potential applications in advanced optical communication systems. PnpP optical thyristors operating at 1.55${\mu}{\textrm}{m}$ are proposed and fabricated for the first time. In the optical thyristors, we employ InGaAs/InP multiple quantum well (MQW) for the active n- and p-layers. The thyristors show sufficiently nonlinear s-shape I-V characteristics and spontaneous emission. In the OFF-state, the device has a high-impedance up to switching voltage of 4.03(V). On the other hand, it has low-impedance and emits spontaneous light as a light-emitting diode in the ON-state voltage of 1.77(V), and switching voltage is changed under several light input conditions. It can be used as a header processor in optical asynchronous transfer mode (ATM), as a hard limiter in optical code division multiple access (CDMA) and as a wavelength converter in optical WDM systems.
김두근(Doo Gun Kim),김선훈(Seon-Hoon Kim),기현철(Hyun-Chul Ki),김회종(Hwe-Jong Kim),오금윤(Geum-Yoon Oh),최영완(Young-Wan Choi) 대한전기학회 2010 전기학회논문지 Vol.59 No.5
We have investigated the grating coupled surface plasmon resonance (GC-SPR) sensors using ZnO nano-grating structures to enhance the sensitivity of an SPR sensor. The GC-SPR sensors were analyzed using the finite-difference time-domain method. The optimum resonance angles of 49 degrees are obtained in the 150 ㎚ wide grating structure with a period of 300 ㎚ for the ZnO thickness of 30 ㎚. Then, the ZnO nano-grating patterns were fabricated by using laser interference lithography. The measured resonance angle of nano-grating patterns was around 49 degrees. Here, an enhanced evanescent field is obtained due to the surface plasmon on the edge of the bandgap when the ZnO grating structures are used to excite the surface palsmon.
전반사 미러와 방향성 결합기를 이용한 직사각형 링 레이저
김두근(Doo Gun Kim),최영완(Young-Wan Choi) 대한전자공학회 2008 電子工學會論文誌-SD (Semiconductor and devices) Vol.45 No.8
본 연구에서는 InP 물질의 능동과 수동 광도파로를 포함하는 신개념의 직사각형 링 레이저를 제작하여 그 특성을 측정하고 분석하였다. 직사각형 링 레이저의 구성은 작은 광 손실을 갖는 네 개의 전반사 미러와 세 개의 수동 광도파로로 구성된 방향성 결합기로 되어 있다. 제작된 두 개의 서로 다른 직사각형 링 공진기의 능동 영역의 길이는 250과 350 ㎛이고, 전체 공진기 길이는 각각 580과 780 ㎛이다. 측정된 링 레이저의 문턱 전류는 상온에서 연속 전류를 인가했을 때 38 ㎃를 얻을 수 있었다. 이때 20 ㏈ 이상의 인접모드 억압비를 갖는 단일 모드 발진 특성을 확인하였다. We have investigated the properties of the novel rectangular ring lasers containing active and passive regions in a InP material system. The rectangular ring laser consists of four low loss total internal reflection mirrors and a directional coupler made out of passive three waveguides. Two different lasers having active lengths of 250 and 350 ㎛ and total cavity lengths of 580 and 780 ㎛ are fabricated, respectively. For both devices lasing thresholds of 38 ㎃ is obtained at room temperature and under continuous wave operation. Lasing is predominantly single mode with the side mode suppression ratio better than 20 ㏈.
다중모드 결합기의 입출력 광도파로 사이에 광결합이 없는 삼각형 링 공진기
김두근(Doo-Gun Kim),김효진(Hyo-Jin Kim),김선훈(Seon-Hoon Kim),기현철(Hyun-Chul Ki),김회종(Hwe-Jong Kim),오금윤(Geum-Yoon Oh),최영완(Young-Wan Choi) 대한전기학회 2010 전기학회논문지 P Vol.59 No.1
We have investigated the properties of the novel triangular ring resonator with the total internal reflection mirrors and the semiconductor optical amplifier for photonic integrated circuits (PIC). A novel triangular resonators containing active and passive sections are fabricated and characterized with various multimode interference (MMI) lengths. The optimum MMI length and width turn out to be 108 and 9 μm, respectively. A free spectral range of approximately 228 GHz is observed near 1558 nm along with an on-off ratio of 9 dB. The proposed triangular resonator has a good advantage to remove the direct coupling between the two access waveguides of the MMI coupler. Hence, such resonators can be directly integrated with other devices making compact and highly functional PIC possible.
김두근(Doo Gun Kim),최운경(Woon-Kyung Choi),최영완(Young-Wan Choi),이종창(Jong Chang Yi) 대한전자공학회 2007 電子工學會論文誌-SD (Semiconductor and devices) Vol.44 No.11
본 연구에서는 광집적회로를 구성하기 위해서 InP 기판위에 아주 작은 다중모드 간섭기를 결합기로 사용하고, 직사각형 링 공진기 내부는 전반사 거울로 구성된 필터를 제작하여 그 특성을 측정 분석하였다. 최적의 다중모드 간섭기의 길이와 폭은 110 ㎛와 9 ㎛로 하여 빛이 광 도파로를 따라 진행할 때 링으로 결합되는 파워를 높였다. 링 공진기 내부의 광도파로와 전반사 거울에서의 손실을 보상하기 위해서 링 공진기 내부에 길이가 120 ㎛인 반도체 광 증폭기를 집적하였다. 측정된 공진기의 FSR는 대략 2 ㎚ (244 ㎓)이고 소광비는 13 ㏈이다. 또한 곡선 피팅에 의해서 파워 결합력은 대략 42%를 얻을 수 있었다. 이러한 조건에서 임계 결합을 얻기 위해서는 2.4 ㏈의 공진기 내부 손실이 요구된다. We characterized the properties of the fabricated filter with the total internal reflection mirror (TIR) in the rectangular ring resonator and very small multimode interference (MMI) couplers on an InP material platform for photonic integrated circuits. Coupling power in and out of a resonator is increased by using an optimum MMI length of 110 ㎛ and a width of 9 ㎛, respectively. The semiconductor optical amplifier with the length of 120 ㎛ is integrated in the resonator to compensate the loss of the internal waveguide and the TIR mirror. A free spectral range of approximately 2 ㎚ (244 ㎓) is observed with an on-off ratio of 13 ㏈. The curve fitting also yields the power coupled per pass as 42%. To reach critical coupling at this coupling level would require a round trip loss of about 2.4 ㏈.
이불화제논 기상 식각에 의한 실리콘 기판의 표면 텍스쳐링 특성
김선훈(Seon Hoon Kim),기현철(Hyun Chul Ki),김두근(Doo Gun Kim),나용범(Yong Beom Na),김남호(Nam Ho Kim),김회종(Hwe Jong Kim) 대한전기학회 2010 전기학회논문지 Vol.59 No.4
We investigated the haze and the surface roughness of textured Si substrates etched by XeF₂ etching system with the etching parameters of XeF₂ pressure, etching time, and etching cycle, Here, the haze was obtained as a function of wavelength from the measured reflectance, The haze of textured Si substrates was strongly affected by the etching parameter of etching cycle. The surface coughness of textured Si substrates was calculated with the haze and the scalar scattering theory at the wavel ngth of BDD ㎚. Then, the surface coughness was compared with that measured by atomic force microscope, The surface coughness5 obtained by two methods was changed with the similar tendency in terms of XeF₂ etching conditions.
유기 발광소자의 효율 향상을 위한 광학박막 및 마이크로렌즈 설계
기현철,김두근,김선훈,김상기,박아름,구할본,Ki, Hyun-Chul,Kim, Doo-Gun,Kim, Seon-Hoon,Kim, Sang-Gi,Park, A-Reum,Gu, Hal-Bon 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.10
We have proposed an optical thin film and micro lens to improve the luminance of organic light emitting device. The first method, optical thin film was calculated refractive index of dielectric layer material that was modulated refractive index of organic material, ITO (indium tin oxide)and glass. The second method, microlens was applied with lenses on the organic device. Optical thin films were designed with Macleod Simulator and Micro Lenses were calculated by FDTD (finite-difference time-domain) solution. The structure of thin film was designed in organic material/ITO/dielectric layer/glass. The lenses size, height and distance were 5 ${\mu}m$, 1 ${\mu}m$, 1 ${\mu}m$, respectively. The material of micro lenses used silicon dioxide. Result, The highest luminance of OLED which applied with microlens was 11,185 $cd/m^2$, when approval voltage was 14.5 V, applied thin film was 5,857 $cd/m^2$. The device efficiency applying microlens increased 3 times than the device which does not apply microlens.
하부 거울층을 이용한 AIGaAs/GaAs 완전 공핍 광 싸이리스터 특성 분석
최운경,김두근,최영완,Choi Woon-Kyiug,Kim Doo-Gun,Choi Young-Wan 대한전자공학회 2005 電子工學會論文誌-SD (Semiconductor and devices) Vol.42 No.1
본 연구에서는 광논리 및 광접속에 응용할 수 있는 GaAs/AIGaAs 구조의 완전 공핍 광 싸이리스터(depleted optical thyristor, DOT)에 1/4 파장 거울층 (quarter wavelength reflector stacks, QWRS)을 제작하여 특성을 측정 분석하였다. 바닥면에 위치한 QWRS는 광 방출 효율뿐만 아니라 흡수 효율을 증가시킨다. 바닥면에 QWRS를 넣은 것과 그렇지 않은 두가지의 DOT를 제작하여 비선형 S-자 형의 전류-전압 특성, 광 방출 효율 및 흡수 효율을 측정, 분석하였다. 하부 거울층을 삽입한 DOT와 기존의 DOT의 스위칭 변화는 각각 1.82 V와 1.52 V로 흡수효율에서 20 % 증가함을 보인다. 뿐만 아니라, 하부 거울층을 이용한 DOT는 기존의 소자에 비하여 발광 효율 면에서 최고 46 % 향상된 결과를 나타낸다. 스위칭 특성을 분석하기 위하여 순방향 전압에서 비선형 s-자형의 전류-전압 특성을, 역방향 전압에서 완전 공핍 전압을 모의실험을 통하여 알아보았다. 모의실험 방법으로 유한 차분 방법 (finite difference method, FDM)을 이용하여 최적화된 DOT 각 층의 두께와 도핑 농도를 구하였다. We fabricate and analyze fully depleted optical thyristors (DOTs) using quarter wavelength reflector stacks (QWRS). QWRS are employed as bottom mirrors to enhance the emission efficiency as well as the optical sensitivity. In order to analyze their switching characteristics, S-shape nonlinear current-voltage curves are simulated and the reverse full-depletion voltages (Vneg's) of DOTs are obtained as function of semiconductor parameters by using a finite difference method (FDM). The fabricated DOTs show sufficient nonlinear s-shape I-V characteristics and switching voltage changes of these devices with and without bottom mirrors show 1.82 V and 1.52 V, respectively. Compared to a conventional DOT, this device with the bottom mirrors shows about 20% and 46% enhancement in switching voltage change and spontaneous emission efficiency, respectively.