• 한국광학회지
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• 제14권2호
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• pp.135-141
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• 2003

양의 열광학 계수를 갖는 실리카를 하부클래드 및 코아에 그리고 음의 열광학 계수를 갖는 폴리머를 상부클래드에 적용한 AWG(Arrayed Waveguide Grating) 파장분할 다중화 소자에 대하여 이차원 스칼라 유한차분법(Scalar Finite Difference Method; SFDM)으로 온도의존 특성을 분석한 결과, 클래드의 굴절률을 변화시키거나 실리카 코어 상부에 실리카 박막이 존재하는 구조에서 박막의 두께를 변화시켜 온도의존 특성을 조절할 수 있음을 확인하였다. 이러한 해석결과에 근거하여 폴리머 상부클래드가 적용된 AWG 소자를 제작하였으며 기존의 실리카 AWG 소자와 특성을 비교분석하였다. 폴리머 상부클래드의 도입에 의해 삽입손실 및 크로스톡은 큰 변화가 없었으나 중심파장의 온도의존성은 0.0130 nm/$^{\circ}C$에서 0.0028 nm/$^{\circ}C$ 수준으로 감소하였다.

• 한국세라믹학회지
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• 제36권3호
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• pp.231-236
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• 1999

냉각속도가 재열처리가 AFD 방법에 의해 제작된 76SiO2-14B2O3-6Na2O-4Al2O3 유리박막의 광학적 특성에 미치는 영향을 조사하였다. 유리박막의 열팽창계수는 30$0^{\circ}C$부터 전이온도 사이에서 약 5$\times$10-6/$^{\circ}C$이었으며, 전이온도는 62$0^{\circ}C$였다. 유리박막을 전이온도 이하에서 열처리할 경우 열처리 시간이 증가함에 따라 굴절률은 증가하였으며, 열처리 온도가 증가함에 따라 굴절률의 증가속도는 더 컸다. 열처리온도에 따른 유리박막의 복굴절(TE-TM)감소는 굴절률이 가장 크게 증가하는 온도인 $600^{\circ}C$에서 가장 효과적이다. 한편, 냉각속도가 증가함에 따라 유리박막의 두께는 증가하였으며, 굴절류른 감소하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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• pp.605-608
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• 2004

A $Pt/Al_xGa_{l-x}N$ Schottky type Ultra-violet photodetector was modeled and simulated using the commercial SILVACO software program. In the carrier transport, we applied field model and other analytic model to determine the electron saturation velocity and low field mobility for GaN and $Al_xGa_{l-x}N$. A C-Interpreter function was defined to described the mole-fraction for the ternary compound semiconductor such as $Al_xGa_{l-x}N$. As comparing the simulated and experimental results, we found that the simulated result for type-1 has $15.9 nA/cm^2$ of leakage current at 5V. We confirmed a good agreement of photo-current in the UV Photo-detector, while applying the absorption coefficient and reflective index of active $Al_xGa_{l-x}N$ and other layers. There had been an intensive search for the proper refractive indices of the layers.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.334.2-334.2
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• 2016

Silicon nitride (SiNx:H) films are generally used as passivation layer on solar cell and they are usually made by plasma enhanced chemical vapor deposition (PECVD). In this study, we investigated the properties of silicon nitride (SiNx:H) films made by PECVD. Effects of mixture ratio of process gases with silane (SiH4) and ammonia (NH3) on the passivation qualities of silicon nitride film are evaluated. Passivation properties of SiNx:H are focused by making antireflection properties identical with thickness and refractive index controlled. The absorption coefficient of each film was evaluated by spectrometric ellipsometery and the minority carrier lifetimes were evaluated by quasi-steady-state photo-conductance (QSSPC) measurement. The optical properties were obtained by UV-visible spectrophotometer. The interface properties were measured by capacitance-voltage (C-V) measurement and the film components were identified by Fourier transform infrared spectroscopy (FT-IR) and Rutherford backscattering spectroscopy detection (RBS) - elastic recoil detection (ERD).

• 센서학회지
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• 제13권5호
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• pp.350-355
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• 2004

A novel UV sensor was manufactured and characterized using the evanescentfield coupling between fiber-planar waveguide (PWG) coupler and prism. A spiroxazine dye was chosen as planar waveguide because its photochromic isomerization induced by UV irradiation. A novel UV sensor was proposed to measure the variation of refractive index and absorption coefficient simultaneously. The wavelength responses of these sensors by UV exposure times were measured 0.48 nm/sec, 0.757 nm/sec, and ATR output power variations were measured $-0.424{\mu}W$/sec and $-0.62{\mu}W$/sec when UV exposure power were 3 mW and 5 mW, respectively.

• Transactions on Electrical and Electronic Materials
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• 제9권4호
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• pp.163-168
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• 2008

Photonic crystal structures have been received considerable attention due to their high optical sensitivity. One of the techniques to construct their structure is the dip-pen lithography (DPN) process, which requires a nano-scale resolution and high reliability. In this paper, we propose a two dimensional photonic crystal array to improve the sensitivity of optical biosensor and DPN process to realize it. As a result of DPN patterning test, we have observed that the diffusion coefficient of the mercaptohexadecanoic acid (MHA) molecule ink in octanol is much larger than that in acetonitrile. In addition, we have designed and fabricated optical waveguides based on the mach-zehnder interferometer (MZI) for application to biosensors. The waveguides were optimized at a wavelength of 1550 nm and fabricated according to the design rule of 0.45 delta%, which is the difference of refractive index between the core and clad. The MZI optical waveguides were measured of the optical characteristics for the application of biosensor.

• Asian Journal of Atmospheric Environment
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• 제9권1호
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• pp.91-99
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• 2015

The Multi-wavelength Raman LIDAR (MRL) system was developed to enable a better understanding of the complex properties of aerosols in the atmosphere. In this study, the microphysical, optical, and radiative properties of mixed aerosols were retrieved using the discrete aerosol observation products from the MRL. The dust mixing ratio, which is the proportion of dust particles to the total mixed, was derived using the particle depolarization ratio. It was employed in the retrieval of backscattering and extinction coefficient profiles for dust and non-dust particles. The vertical profiles of aerosol optical properties were then used as input parameters in the inversion algorithm for the retrieval of microphysical parameters including the effective radius, refractive index, and the single scattering albedo (SSA). Those products were successfully applied to an analysis of radiative flux using a radiative transfer model. The relationship between the MRL derived extinction and aerosol radiative forcing (ARF) in short-wavelength was assessed over Gwangju, Korea. The results clearly demonstrate that the MRL-derived extinction profiles are a good surrogate for use in the estimation of optical, microphysical, and radiative properties of aerosols. It is considered that the analytical results shown in this study can be used to provide a better understanding of air quality and the variation of local radiative effects due to aerosols.

• 한국안광학회지
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• 제12권1호
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• pp.85-90
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• 2007

안경렌즈의 무반사 코팅물질로 사용되는 황화아연(Zinc Sulphide : ZnS)의 단일박막을 실리콘과 슬라이드 유리 기판위에 스핀코팅방법으로 증착하였다. 박막 증착 후 변입사각분광타원계(VASE : Variable Angle Spectroscopic Ellipsometer)를 사용하여 1.5~5.0 eV 광 에너지 영역에서 타원 각(ellipsometry angle) ${\Delta}$, ${\Psi}$를 측정하였다. 이 측정결과들을 Jellison Modine 분산관계식을 사용하여 최적맞춤하고, 매개변수들을 구하여 박막의 광학상수인 굴절계수 $n({\lambda})$와 소광계수 $k({\lambda})$를 결정하였다.

• 전자공학회논문지D
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• 제34D권5호
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• pp.22-31
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• 1997

We have measured the optical properties, thickness, and energy band gap of the P $b_{1-x}$/100/L $a_{x}$100/ $Ti_{1-}$0.25x/100/ $O_{3}$ (PLT(x)) thin film prepared by the sol-gel method with varying the La concentration, x, fyom 15 nto 33 mol%. We have obtained the values from the tranmission spectrum and employed the envelope method in anayzing the spectrum. We have also performed the simulation of the transmission spectrum on the PC (personal computer) to verify the accuracy of the values 15 to 33mol%, the refractive index (at .lambda.=632.8nm) increases from 2.39 to 2.44. The extinction coefficient does not depend on the la concentration but mainly on te wavelength, and has the values between 0.2 and 0.5 at the wavelength shorter than 330nm and between 0.001 and 0.008 at the wavelength longer than 700nm. The energy band gap of the PLT (x) thin film has been obtained on the assumption of the direct band-to-band transition. It decreases from 3.28 to 3.17eV as the La concentration increases from 15 to 33 mol%. The thickness of the PLT(x) thin film has been also obtained in high accuracy by the envelope method..

• E2M - 전기 전자와 첨단 소재
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• 제10권3호
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• pp.210-216
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• 1997

The th ermal and optical properties of multicomponent oxide glass optical fiber by adding heavy metal oxide Ga$_{2}$O$_{3}$(0-20wt%) were investigated. The fiber samples were made by the method of rod in tube. The optical loss of fiber was measured in 0.3-1.8.mu.m wavelength region. As Ga$_{2}$O$_{3}$ increased up to 20wt%, the transition and softening temperature of bulk glass were increased from 495.deg. C to 579.deg. C and from 548.deg. C to 641.deg. C, respectively. Whereas the thermal expansion coefficient was decreased from 102 to 79.1x10$^{-7}$ /.deg. C. The refractive index was increased from 1.621 to 1.665, and IR cut-off wavelength was enlarged from 4.64.mu.m to 6.1.mu.m. The optical loss of fiber was remarkably decreased in 1.146.mu.m-1.8.mu.m wavelength region.