• Title/Summary/Keyword: Maximum Reflectance

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Design of Integrated-Mirror Etalons for Surface-Emitting Lasers and Photonic Switching (광스위칭과 표면 발진 레이저를 위한 집적 거울 Etalon의 설계)

  • 정종술;윤태훈;김재창
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.3
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    • pp.41-46
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    • 1992
  • In this paper we report how to design integrated-mirror etalons for surface-emitting lasers and photonic switching without time-consuming numerical calculation. It consists of the following two-step process (step 1) find the minimum reflectance to achieve the maximum allowable linewidth. (step 2) find the number of the quarter-wave layers in each mirror to realize the reflectance given by step 1. The condition for maximum transmission in an integrated- mirror etalon is also derived. Under this condition we can achieve the required linewidth with the minimum number of quarterwave layers.

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Reflectance spectrum properties of DBR and microcavity porous silicon (Distributed Bragg Reflector, Microcavity 구조를 갖는 다공질규소의 반사율 스펙트럼)

  • Kim, Young-You;Kim, Han-Jung
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.6
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    • pp.293-297
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    • 2009
  • In this paper, we made three kinds of porous silicon samples (single layer, distributed Bragg reflector, and microcavity) by electrochemical etching p-type silicon substrate. And then, we investigated their reflectance spectrum properties. We found that the number of fringe patterns and the maximum reflectivity of porous silicon multilayer increased compared with a porous silicon sinlge layer. In addition, we can observe that the DBR (distributed Bragg reflector) porous silicon has a full-width at half-maximum about 33 nm which is narrower than the porous silicon single layer and porous silicon microcavity.

Characteristics of a Bimetal-Layer Chip of a Surface Plasmon Resonance Sensor in the Intensity Interrogation for Tumor Marker Detection

  • Kim, Hyungjin;Kim, Chang-duk;Sohn, Young-Soo
    • Journal of Sensor Science and Technology
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    • v.25 no.4
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    • pp.243-246
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    • 2016
  • The characteristics of a bimetallic surface plasmon resonance (SPR) chip were investigated to detect a tumor biomarker, carcinoembryonic antigen (CEA). The linewidth and the tangential slope of the reflectance curve of the bimetallic SPR chip was compared with those of the reflectance curve of a conventional gold (Au) SPR chip. The changes in reflectance in response to the variation in CEA in the critical concentration range were analyzed at an angle where the tangential slope of the reflectance curve was maximum. From linear regression analysis, the sensitivity of the bimetallic SPR chip with respect to the CEA in critical concentration was obtained.

Analysis of Spectral Reflectance Characteristics for Sand and Silt Turbid Water (모래와 실트의 탁수에 대한 분광특성 분석)

  • Shin, Hyoung-Sub;Lee, Kyu-Ho;Park, Jong-Hwa
    • Journal of The Korean Society of Agricultural Engineers
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    • v.51 no.3
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    • pp.37-43
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    • 2009
  • The objective of this study was to investigate the basic relationships between spectral reflectance and varying concentrations of sediment in surface waters. An experimental method for determining suspended sediment concentration (SSC) in the water by use of a spectroradiometer above the water surface, in visible and near-infrared (NIR) wavelengths, is applied. The main advantage of the method is the direct comparison of spectral reflectance and the SSC, but it requires an accurate knowledge of the water body and sediment. Therefore numerous spectroradiometric measurements are carried out in situ measurements, for SSC, ranging from zero to 100 percentage and two types of sediment applied in the water tank. The results indicate that the suspended sediment causes increasing spectral reflectance response in waters. We observed that spectral reflectance increases with SSC, first at the lower wavelengths (430-480 nm), then in the middle wavelengths (570-700 nm), and finally, in the NIR domain (800-820 nm); a characteristic maximum reflectance appears at 400-670 nm. Relationships between the wavelength, integral value, and the SSC were evaluated on the basis of the regression analysis. The regression curve for the relation between the wavelength, integral value, and the SSC were determined ($R^2$>0.98). Finally, the specular wavelength can be estimated to recognize the sediment and to improve SC estimation accuracy in the water.

Analysis of the Correlation between Compaction Characteristics and Spectral Information of Reactive Materials for Absorption of Oil Contaminant (유류 오염물 흡수가 가능한 반응재료의 다짐 특성-분광정보 상관관계 분석)

  • Gigwon Hong
    • Journal of the Society of Disaster Information
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    • v.19 no.4
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    • pp.950-957
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    • 2023
  • Purpose: The response technology is needed to prevent the spill of highly toxic oil contaminants in advance. Therefore, this paper described the results of an experimental study to predict the engineering properties of the developed reactive material. Method: Compaction tests and spectral information acquisition experiments were conducted on the reactive materials, and the results were evaluated. In addition, the correlation between spectral information and maximum dry unit weight was analyzed to evaluate the possibility of predicting the engineering properties for reactive materials. Result: The compaction test results showed that the maximum dry unit weight was in the range of approximately 9kN/m3 to 10kN/m3. The spectral information confirmed that the maximum reflectance decreased as the polynorbornene decreased. Conclusion: It was confirmed that the maximum dry unit weight of the reactive material for absorbing oil contaminants can be predicted using the maximum reflectance according to the component ratio of the reactive material.

Relationship between maceral composition and some parameters indicating the degree of coalification (석탄화도의 지표와 석탄조직성분과의 관계)

  • 박홍수
    • Economic and Environmental Geology
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    • v.32 no.1
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    • pp.83-91
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    • 1999
  • Coal properties are controlled by the following two factors : One is the maceral components and the other is the degree of coalification. In other words, even if coals in question indicate the same degree of coalification, their chemical and physical properties considerably vary one another when their maceral components are different. It is well known that virtrinite reflectance is the best single criterion for the degree of coalification covering the whole range of coal rank. Some authors have recently insisted that sporinite fluorescence is more leliable coal rank parameter than vitrinite reflectance in case of low rank coals. In this paper, to examine the relince of sporinite fluorescence as coal rank parameter, fluidity analysis of coals is newly performed and the data are analyzed in comparision with those of virinite reflectance, sporinite fluorescence and maceral components. The results of this study are as follows; 1) Vitrinite reflectance becomes low when degradinite content is high within one columnar samples, and vice versa. 2) variation of vitrinite reflectance depend on degradinite content and on difference of roiginal plant. 3) In dealing with the Japanese paleogene coals, sporinite fluorescence is more reliable parameter indicating the degree of coalification than vitrinite reflectance. 4) Maximum fluidity increases exponetially in proportion to the increases of degradinite content.

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Comparison of Performance of Models to Predict Hardness of Tomato using Spectroscopic Data of Reflectance and Transmittance (토마토 반사광과 투과광 스펙트럼 분석에 의한 경도 예측 성능 비교)

  • Kim, Young-Tae;Suh, Sang-Ryong
    • Journal of Biosystems Engineering
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    • v.33 no.1
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    • pp.63-68
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    • 2008
  • This study was carried out to find a useful method to predict hardness of tomato using optical spectrum data. Optical spectrum of reflectance and transmittance data were collected processed by 9 kind of preprocessing methods-normalizations of mean, maximum and range, SNV (standard normal variate), MSC (multiplicative scatter correction), the first derivative and second derivative of Savitzky-Golay and Norris-Gap. With the preprocessed and non-processed original spectrum data, prediction models of hardness of tomato were developed using analytical tools of PLS (partial least squares) and MLR (multiple linear regression) and tested for their validation. The test of validation resulted that the analytical tools of PLS and MLR output similar performances while the transmittance spectra showed much better result than the reflectance spectra.

A Study on the Output Power of Shingled Mini Module Depending on Reflectance of Backsheets (Backsheet 반사율에 따른 Shingled Mini Module 출력변화에 대한 연구)

  • Cho, Seong Hyeon;Moon, Ji Yeon;Son, Hyoung Jin;Jun, Da Yeong;Kim, Sung Hyun
    • Current Photovoltaic Research
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    • v.8 no.4
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    • pp.129-133
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    • 2020
  • It is very important to optimize the reflectance of incident light in solar modules for improving output power and reducing loss of cell-to-module (CTM). It is assumed that a higher reflectance backsheet may improve optical efficiency. However how much output power is related to optical properties by reflectance property of backsheets have not been revealed clearly yet. A total of 3 types of industrial backsheets with 3 type of industrial encapsulants (EVA or POE) were analyzed as fabricated mini modules used shingled cells. According to the type of backsheets, the difference between the highest and lowest average reflectance in the range of 400 nm to 1200 nm was found to be 13.08% by UV-visible spectroscopy. Also, when using the same encapsulant, the maximum gap value of the output power increase was measured by about 3.755 mW% (166.02 mW). The correlation between reflectance and output power was experimentally found by measuring the output property of the fabricated shingled mini modules.

Numerical Investigation on Surface Plasmon Resonance Sensor Design with High Sensitivity Using Single and Bimetallic Film Structures (고감도 단금속 및 쌍금속 표면 플라즈몬 공명 센서 설계를 위한 수치해석 연구)

  • Gwon, Hyuk-Rok;Lee, Seong-Hyuk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.4
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    • pp.795-800
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    • 2009
  • Surface plasmon resonance (SPR) has been widely used for biological and chemical sensing applications. The present study investigates numerically the optical characteristics for the single Au film and bimetallic Ag/Au film SPR configurations by using the multiple beam interference matrix (MBIM) method. We use the prism coupling method, especially Kretschmann configuration for excitation of surface plasmon wave (SPW). The estimated results of reflectance, phase shift and magnetic field intensity enhancement factor are provided for finding out the optimum configuration with high sensitivity for SPR measurement. As a result, the optimum thicknesses are found to be 52 nm for a single Au film and 5 nm to 36 nm for bimetallic Ag-Au film. From the comparison of full width half maximum (FWHM) values for reflectance, phase shift, and enhancement of magnetic field intensity, it is concluded that the highest sensitivity can be obtained when using the phase shift for SPR sensor.

The Classification and Age Determination of Ballpoint Pen Inks in Questioned Documents

  • Kim, Nam Yee;Park, Sung Woo;Doble, Philip;Roux, Claude
    • Analytical Science and Technology
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    • v.17 no.3
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    • pp.271-277
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    • 2004
  • The aim of this study was to investigate questioned documents written with blue or black ballpoint pen on paper by nondestructive technique. In this work, 21 blue and 22 black ballpoint pen inks which were purchased on different brands were analyzed by using Microspectrophotometry (MSP). The reflectance spectra were obtained from these ink samples and their shapes and the wavelength of the maximum intensity were compared. In the blue and black ballpoint pen inks, the discriminating powers (DP) were 0.85 and 0.61, respectively. The changes of the reflectance intensity at their wavelength of maximum intensity and their shapes appeared according to the exposure time to sunshine in a laboratory, especially in the blue ballpoint pen inks. Therefore it is possible to distinguish ink entries on the same paper with the relative age in case of questioned letters written with blue ballpoint pen.