• 제목/요약/키워드: optical losses

검색결과 153건 처리시간 0.025초

직관형 LED램프의 구성부품별 광손실에 관한 연구 (A Study on Optical Losses for Tubular LED Lamp's Components)

  • 정희석;박창규
    • 조명전기설비학회논문지
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    • 제25권7호
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    • pp.1-8
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    • 2011
  • The high efficiency tubular LED lamp has been developed. But, it occurs optical losses in consists of LED package, module, diffuser etc.. By Measuring the tubular LED lamp's luminous flux, we compared and analyzed about the effect of optical losses for each component and actually using measured luminous intensity distribution data, illuminance distribution was simulated by Relux. Optical losses are 24[%] from LED package to luminaire and the tubular LED lamp can be replaced with fluorescent lamp. In this paper, we could provide data for optimum lighting design by analyzing the optical characteristics for developing and propagating the tubular LED lamp.

복굴절, 입력 편광상태 및 광손실이 광섬유간섭계의 visibility에 미치는 영향 (The visibility variation of the mach-zehnder optical fiber interferometerdue to birefringences, input states of polarization and optical losses)

  • 강현서;이영택;이경식
    • 전자공학회논문지A
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    • 제33A권2호
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    • pp.140-147
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    • 1996
  • The output of the mach-zehnder optical fiber interferometer varies with birefringences existing in the figer arms. New equations experessing for the visibility of the mach-zehnder interferometer were derived in terms of a number of parameters related to the birefringences, the input SOP and the optical losses. Based on the equations the visibility of the interferometer was simulated in different cases. Some maximum visibility conditons were also presented.

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개구 크기에 따른 테라헤르츠 표면 발광 반도체 레이저의 광손실에 대한 연구 (Estimation of optical losses in dielectric apertured terahertz vertical cavity lasers)

  • 유영훈
    • 한국광학회지
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    • 제14권1호
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    • pp.92-96
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    • 2003
  • 공진기 내에 유전체 개구를 채용하고, $a-So/SiO_2_2$를 브라그 거울로 이용하고, 발진 파장이 38 $\mu\textrm{m}$인 표면 발광 테라헤르츠 레이저의 브라그 거울의 반사율을 계산하여 공진기 내 개구에 의한 회절 손실을 계산하였다. 공진기 내 개구의 크기, 위치, 두께 모두 회절 광 손실에 영향을 주는 것을 알 수 있었다 개구의 크기가 발진 파장의 5배 이상이면 개구의 두께가 회절 손실에 미치는 영향이 미미하나, 개구의 크기가 발진 파장보다 작은 경우에는 개구의 두께가 회절 광 손실에 많은 영향을 주는것을 알 수 있었다. 이러한 회절 손실을 줄이고 충분한 반사율을 얻기 위해서는 레이저 개구의 두께가 3nm 경우에 개구의 크기는 적어도 1$\lambda$이상이 되어야 함을 알 수 있었다.

Concentric Core Fiber Design for Optical Fiber Communication

  • Nadeem, Iram;Choi, Dong-You
    • Journal of information and communication convergence engineering
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    • 제14권3호
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    • pp.163-170
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    • 2016
  • Because of rapid technological advancements, increased data rate support has become the key criterion for future communication medium selection. Multimode optical fibers and multicore optical fibers are well matched to high data rate throughput requirements because of their tendency to support multiple modes through one core at a time, which results in higher data rates. Using the numerical mode solver OptiFiber, we have designed a concentric core fiber by investigating certain design parameters, namely core diameter (µm), wavelength (nm), and refractive index profile, and as a result, the number of channels, material losses, bending losses, polarization mode dispersion, and the effective nonlinear refractive index have been determined. Space division multiplexing is a promising future technology that uses few-mode fibers in parallel to form a multicore fiber. The experimental tests are conducted using the standard second window wavelength of 1,550 nm and simulated results are presented.

원형으로 굽은 광도파로의 low bending loss를 위한 trench 구조설계: 원통좌표계 FD-BPM (A Trench Structure for Low Bending Loss of Bent Optical Waveguides)

  • 한영진;김창민
    • 한국광학회지
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    • 제6권4호
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    • pp.373-378
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    • 1995
  • 원통좌표계에서의 FD-BPM(finite difference-beam propagation method)을 이용하여 굽은 광도파로의 bending loss를 계산하였다. Bending loss를 최소화하기 위해 trench구조를 적용하였으며 다음의 세가지 측면에서 해석하였다. 1)trench구조가 없을때 곡률반경에 따른 bending loss, 2)폭과 위치가 일정한 trench구조가 있을때 곡률반경과 굴절율차에 따른 bending loss, 3)trench의 위치가 일정할 때 trench의 폭에 따른 bending loss를 계산하였다.

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포화흡수체 $Cr^{4+}:YAG$와 유기염료 박막의 포화특성 분석 (The saturating property of $Cr^{4+}:YAG$and dye film as the saturable absorber)

  • 최영수;전용근;김재기
    • 한국광학회지
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    • 제12권2호
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    • pp.98-102
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    • 2001
  • 포화흡수체$Cr^{4+}:YAG$와 유기염료 박막을 사용한 $1.06{\mu}m$ Nd:YAG 공진기에서 수동 큐스위칭 동작시 나타나는 포화흡수체의 포화특성을 분석하였다. 정상모드와 수동 큐스위칭 레이저의 문턱에너지 차이로 광손실을 측정하여 큐스위칭 동작에서 나타나는 포화흡수체의 포화투과도와 불포화 기저상태 밀도수를 분석하였다.

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하다마드 분광계측기의 마스크 설계 (A Design of Optimal Masks in Hadamard Transform Spectrometers)

  • 박진배
    • 대한의용생체공학회:의공학회지
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    • 제16권2호
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    • pp.239-248
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    • 1995
  • The method of increasing signal to noise ratio (SNR) in a Hadamard transform spectrometer (HTS) is multiplexing. The multiplexing is executed by a mask. Conventional masks are mechanical or electro-optical. A mechanical mask has disadvantages of jamming and misalignment. A stationary electro-optical mask has a disadvantage of information losses caused by spacers which partition mask elements. In this paper, a mixed-concept electro-optical mask (MCEOM) is developed by expanding the length of a spacer to that of lon-off mask element. An MCEOM is operated by stepping a movable mask. 2N measurements are required for N spectrum estimates. The average mean square error (AMSE) using MCEQM is equal to that using a stationary electro-optical mask without spacers for large N. The cost of manufacturing an MCEOM is lower than that of producing a conventional electro-optical mask because an MCEOM needs only (N + 1)/2 on-off mask elements whereas the con¬ventional electro-optical mask needs N on-off mask elements. There are no information losses in the spectrometers having an MCEOM.

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결정질 실리콘 태양전지의 광학적 손실 감소를 위한 표면구조 개선에 관한 연구 (Investigation of the surface structure improvement to reduce the optical losses of crystalline silicon solar cells)

  • 이은주;이수홍
    • 신재생에너지
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    • 제2권2호
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    • pp.4-8
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    • 2006
  • Reduction of optical losses in crystalline silicon solar cells by surface modification is one of the most important issues of silicon photovoltaics. Porous Si layers on the front surface of textured Si substrates have been investigated with the aim of improving the optical losses of the solar cells, because an anti-reflection coating and a surface passivation can be obtained simultaneously in one process. We have demonstrated the feasibility of a very efficient porous Si AR layer, prepared by a simple, cost effective, electrochemical etching method. Silicon p-type CZ (100) oriented wafers were textured by anisotropic etching in sodium carbonate solution. Then, the porous Si layer were formed by electrochemical etching in HF solutions. After that, the properties of porous Si in terms of morphology, structure and reflectance are summarized. The surface morphology of porous Si layers were investigated using SEM. The formation of a porous Si layer about $0.1{\mu}m$ thick on the textured silicon wafer result in an effective reflectance coefficient Reff lower than 5% in the wavelength region from 400 to 1000nm. Such a surface modification allows improving the Si solar cell characteristics.

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