• 제목/요약/키워드: Refractive index change

검색결과 187건 처리시간 0.024초

U-Shaped의 POF probe를 이용한 굴절률 변화 측정 Refractive Index Monitoring Using U-shaped POF probe

  • 김승필;김기수;김동민
    • 한국광학회:학술대회논문집
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    • 한국광학회 2009년도 동계학술발표회 논문집
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    • pp.291-292
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    • 2009
  • Refractive index monitoring using U-shaped POF (Plastic optical fiber) in the sugar solution and salt solution were performed. The various bending losses of U-shaped POF due to the environmental refractive index changes of the measurand solution. The loss increases according to the amounts of solute in the solution which causes the refractive index change in the solution.

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CR-39 렌즈 착색시간에 따른 굴절률(n) 변화 (The Refractive Index Change for Tinted Time of CR-39 Lens)

  • 김용근
    • 한국안광학회지
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    • 제5권2호
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    • pp.151-155
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    • 2000
  • 칼라 렌즈 제작시 착색 시간에 따른 분광반사율을 측정하여 렌즈표면의 굴절률을 계산하였다. 착색 시간이 길수록 반사율과 굴절률은 커진다. 렌즈 표면에 착색물질이 포화상태가 될 때까지 굴절률은 시간에 따라 증가하였다. 시간에 따른 blue color 렌즈의 굴절률 변화 곡선은 Boltzmann 성장곡선을 따르며, 이때 $n_{min}$은 1.482. $n_{max}$는 1.497. $t_c=11.53$ 그리고 $d_0$ 등의 2.287 등의 parameter 값을 얻었다.

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Field-induced refractive index variations in GaAs/AlGaAs multiple quantum well waveguide modulator

  • Cho, Wook-Rae;Park, Seung-Han;Kim, Ung;Park, Kyung-Hyun
    • Journal of the Optical Society of Korea
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    • 제1권1호
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    • pp.48-51
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    • 1997
  • A quantum well electroabsorption waveguide modulator utilizing a field-induced refractive index change was designed and fabricated. The on/off ratios of the device were investigated as a function of wavelength over the spectral range of 850 nm to 910 nm for the various reverse biases. The field-induced refractive index variations associated with quantum-confined Stark effect was theoretically obtained based on the measured on/off ratios. The resulting maximum refractive index change(${\DELTA}n) of ~7.5 {\times} 10^{-4}$ at -8 V was estimated.

투과형 홀로그램과 반사형 홀로그램에서의 Bragg detuning 현상에 대한 연구 (Study for the Bragg Detuning Effects on the Transmission Holograms and the Reflection Holograms)

  • 권윤영;김근율;박주연
    • 정보저장시스템학회논문집
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    • 제2권3호
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    • pp.189-195
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    • 2006
  • Bragg detuning effect if, one of the serious problems if the photopolymer is used for the recording material of holography memories. And the critical reasons of that are known as the bulk refractive index change and shrinkage of recording material. However, the trials for analyzing the effect are mainly on the K-sphere and biased on the transmission hologram. So, we approached Bragg detuning effect numerically and applied the method to the transmission holograms and the reflection holograms all together. We simulated it with MATLAB. As a result, the bulk refractive index change causes+Bragg detuning effect on the transmission holograms and the reflection holograms. But the shrinkage leads to+Bragg detuning effect on the transmission hologram and-Bragg detuning effect on the reflective hologram. Compared to experimental result, the bulk refractive index change(${\fallingdotseq}4{\times}10^{-4}$) and the ratio of shrinkage to the thickness of the material(${\fallingdotseq}1.67{\times}10^{-3}$) could be matched with Bragg detuning effect on the transmission hologram and the reflection hologram.

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$SiO_2$ 첨가에 따른 알루미네이트 유리의 굴절률 분산 특성 (Refractive Index Dispersion of Aluminate Glasses on the Addition of $SiO_2$)

  • 원종원;정용선;오근호
    • 한국세라믹학회지
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    • 제34권7호
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    • pp.693-698
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    • 1997
  • The refractive index and dispersion in the (100-x)(0.6CaO.0.4Al2O3).xSiO2(x=0~30) glasses were investigated. As the amount of SiO2 increased, the refractive index decreased. The change of refractive index was attributed to the change of the molar refraction rather than the molar volume. When the amount of SiO2 was smaller than 20 mol%, the average electronic transition energy gaps(E0) and the electronic oscillator strengths(Ed) were about 10.9($\pm$0.1) nd 18($\pm$0.5)eV, respectively. However E0 and Ed of the glass (CAS30) with 30 mol% SiO2 increased to 12.63 and 19.89eV, respectively. The similar results was observed in the variation of Abbe Number. Abbe number of the glass in the range of 0~20 mol% SiO2 was about 46 and that of CAS30 increased to 60. The zero-material dispersion wavelength({{{{ lambda }}0) of pure calcium aluminate glass was 1.8 ${\mu}{\textrm}{m}$. As the amount of SiO2 increased, the zero-material dispersion wavelength shifted to a shorter wavelength. {{{{ lambda }}0 of CAS30 was 1.5 ${\mu}{\textrm}{m}$, that is currently using for the optical telecommunication system.

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$Gd_{2}(MoO_{4})_{3}$ 단결정의 강탄성구역과 굴절률특성 (Ferroelastic Domain and Refractive Property of $Gd_{2}(MoO_{4})_{3}$ Single Crystal)

  • 손중윤;이찬구;이수대;김재형
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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    • pp.98-102
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    • 2002
  • We investigated domains and conoscope under the polarizing microscope and the index of refraction on the c-plate GMO which has the ferroelectric and ferroelastic phase at room temperature. To observed the change of refractive index in connection with domain, we developed an apparatus to obtain the refractive index by measuring the Brewster's angle. The resolution of the minimum rotation angle of this apparatus is $0.001^{\circ}$. To obtain the refractive index map on the sample, the moving distance of XY stage loaded sample holder is 60 mm and the minimum moving distance is 0.002 mm. Also, To obtain the indicatrix for single crystal, vertical turntable with sample holder and XY stage was loading on horizontal turntable. The minimum resolution angle of this vertical turntable is $0.001^{\circ}$. We measured the refractive index of transparent materials such as ferroelectrics. In the case of $Gd_{2}(MoO_{4})_{3}$, the Brewster angle is $62.11^{\circ}$ and then, the refractive index is 1.8895 by using He-Ne Laser. Also the refractive distribution of c-plate GMO was obtained with $400{\mu}m{\times}120{\mu}m$.

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스퍼터링 방법으로 증착된 실리콘 과잉 실리카 박막의 굴절률 분산 (Refractive Index Dispersion of Sputter-Deposited Silicon-Rich Silica Thin Films)

  • 진병규;최용규
    • 한국세라믹학회지
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    • 제46권1호
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    • pp.10-15
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    • 2009
  • We have fabricated silicon-rich silica thin films via RF magnetron sputtering using a SiO target. Thickness evolution and microstructure change of such $SiO_x$ (1$SiO_x$ thin films turned out to be mainly responsible for the increase of refractive index.

FBG를 이용한 고온 측정 센서의 온도특성 (Thermal characteristics of high-temperature measurement sensor using fiber Bragg grating)

  • 손용환;한상국
    • 센서학회지
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    • 제17권4호
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    • pp.261-266
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    • 2008
  • In this paper, we present thermal characteristics of high-temperature measurement sensor using fiber Bragg grating(FBG), including peak reflectivity, FWHM bandwidth and various normalized refractive index change along temperature variation. The temperature stability of FBG temperature sensor can be changed by varying the refractive index change and grating length. The proposed FBG temperature sensor can measure up to about $600^{\circ}C$ and 1000 hours of heating time.

Cure real monitering sensor for UV curable thin epoxy film based on side-polished single mode fiber

  • Kim, Kwang-Taek;HwangBo, Sueng;Kang, Yong-Chul
    • 센서학회지
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    • 제16권4호
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    • pp.254-258
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    • 2007
  • A novel cure sensor based on the side-polished single mode fiber has been proposed and demonstrated. Two different UV curable epoxies were used to verify the feasibility of the side-polished single mode fiber as a high sensitivity cure sensor. The volume change of the epoxy by UV curing results in a corresponding change of the refractive index. The sensor can be used to monitor the curing process, the refractive index variation and the volume change of epoxy in real time during the UV curing process. In addition, small birefringence of the epoxy film can be detected using the sensor.

Generation of Graded Index Profile of Poly(methyl methacrylate) by a Photochemical Reaction

  • Yun, Hyun-Chu;Im, Sang-Hyuk;Suh, Duck-Jong;Park, O-Ok;Kwon, Moo-Hyun
    • Macromolecular Research
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    • 제11권4호
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    • pp.236-240
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    • 2003
  • Fabrication of a graded index profile was possible via photochemical reaction of cinnamoyl groups with 350 nm wavelength UV light to form crosslinked structures. Such structural change may induce the change in the refractive index. In order to generate graded index profile in the PMMA polymer optical fiber (POF) with cinnamoyl groups by photochemistry, a methyl methacrylate monomer containing a cinnamoyl functional group in the side chain were prepared. This monomer was then copolymerized with methyl methacrylate with various compositions not only to utilize advantages of poly(methyl methacrylate) but also to overcome the drawbacks of the cinnamate homopolymer. Changes of refractive indices were investigated with various contents of cinnamoyl group and varying irradiation time. Large change in the refractive index (${\Delta}{\approx}0.01$) and its proper profile shape ($g{\approx}2.2$) can be obtained by changing irradiation time.