• Title/Summary/Keyword: 광필터

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Acousto-Optic Wavelength-Tunable Bandpass Filter (음향광학 파장가변 대역투과 필터)

  • 이명수;황인각;김병윤
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.08a
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    • pp.146-147
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    • 2000
  • 광 대역투과 필터$^{(1)(2)}$ 는 WDM 광통신 시스템에서의 채널 선별에 사용되거나 좁은 선폭의 광원을 제작하는 데 사용된다. 또한 광원의 파장을 분석하는 광스펙트럼 분석기나 광섬유 센서 시스템에서 신호처리용 파장 필터 등으로도 널리 쓰이고 있는 중요한 광소자 중에 하나이다. 본 연구에서는 코어 모드감쇠기와 음향광학 가변 필터$^{(3)}$ 를 사용하여 새로운 전광섬유 형태의 광 대역투과 필터를 구현하였다. 본 광 대역투과 필터는 필터의 중심 파장 및 필터의 투과율을 전기적으로 쉽고 빠르게 제어할 수 있다는 장점을 가지고 있다. (중략)

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Fiber to planar waveguide type tunable comb filter using thermo-optic effect (열광학 효과를 이용한 광섬유 -평면도파로 결합형 파장 가변 빗살필터)

  • 김정훈;권광희;김광택;송재원
    • Proceedings of the Optical Society of Korea Conference
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    • 2002.07a
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    • pp.192-193
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    • 2002
  • 지금까지 측면이 코어 가까이 연마된 잔일모드 광섬유와 평면 도파로 사이의 광결합을 이용한 소자들이 많이 연구되고 있다. 이를 이용한 소자들로는 광필터, 광변조기, 광스위치, 굴절계, 편광기 등이 있으며 최근에는 파장분할다중화(WDM)에서 인접채널간의 채널분리를 위한 소자로서 빗살필터의 연구 또한 활발히 이루어지고 있다. 이에 본 논문에서는 측면이 코어 가까이 연마된 단일모드 광섬유와 평면도파로 사이의 광결합을 이용한 빗살필터를 제작하였으며 열광학 효과를 이용하여 파장 가변 빗살 필터를 구현해 보았다. (중략)

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A Study on Transmission Performance for Optical Duobinary Transmitters at 40Gbps (40Gbps에서 광 듀오바이너리 송신기의 전송 특성에 관한 연구)

  • Lee, Dong-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.3
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    • pp.43-49
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    • 2014
  • This paper presents a theoretical study of transmission performance for an optical duobinary transmitter employed a Mach-Zehnder modulator and a electrical low pass filter at 40Gbps optical communication links. It depends on the bandwidth of the low pass filter in the transmitter, the optical filter and the filter in the receiver. Also, each filter affected to the various parts of the optical power spectrum. By optimizing the bandwidth of each filter, we could control the side robes and the ripples and improve the dispersion tolerance of the transmission system.

Dispersion Tolerance for Optical Duobinary Transmitters based on a Mach-Zehnder Modulator and an Optical Filter (마크-젠더 변조기와 광 필터를 사용한 광 듀오바이너리 송신기의 분산 내성에 관한 연구)

  • Lee, Dong-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.4
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    • pp.141-145
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    • 2011
  • We theoretically investigated dispersion tolerance of an optical duobinary transmitter employed a Mach-Zehnder modulator and an optical filter. Compared to the optical transmitter based on a Mach-Zehnder modulator and an optical delay interferometer by optimizing the applied voltage for improving the dispersion tolerance, the demonstrated duobinary transmitter provides improved receiver sensitivity and higher dispersion tolerance while maintaining narrow spectral bandwidth.

광통신용 광학 박막의 최신 기술 동향

  • 황보창권
    • The Optical Journal
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    • v.13 no.1 s.71
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    • pp.60-72
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    • 2001
  • 광통신 기술의 발달에 따라 광학 박막을 이용한 광학 소자가 많이 사용되고 있으며, 다양하고 정교한 광학소자로서 광학박막이 계속 많이 사용될 것으로 기대되고 있다. 광통신 광학박막, 파장 다중 분할 필터(WDM), 이득 평탄 필터, 파장 가변 패브리-페로 필터, 증착 방법을 소개한다.

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Optical wavelet filter for Rotation and Scale-Invariant Pattern Recognition of images with Noise (잡음영상의 크기와 회전불변 패턴인식을 위한 광 웨이블릿 필터)

  • 이승희
    • Journal of Korea Society of Industrial Information Systems
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    • v.9 no.2
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    • pp.81-88
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    • 2004
  • For scale and rotation invariant pattern recognition of images with noise, an optical wavelet CHF-fSDF filter is proposed. Wavelet CHF-fSDF filter is synthesized by each single CHF extracted from scale-changed and wavelet transformed images for a referene image as training images. The proposed optical wavelet CHF-fSDF filter is the type of the matched filter so that it can use the structure of 4f optical correlation system. The results of computer simulation show that the proposed filter has the rotation and scale-invariant correlation output and it is useful in the noisy input.

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Optical Wavelet POfSDF-FSJTC for Scale Invariant Pattern Recognition with Noise (잡음을 갖는 물체의 크기불변인식을 위한 광 웨이브렛 POfSDF-FSJTC)

  • Park Se-Joon;Kim Jong-Yun
    • The Journal of the Korea Contents Association
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    • v.4 no.4
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    • pp.205-213
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    • 2004
  • In this paper, we proposed a wavelet phase-only filter modulation synthetic discriminant function joint transform correlator(WPOfSDF-JTC) for scale invariant pattern recognition, and an improved algorithm to reduce the filter synthesis time. Computer simulation showed that the proposed filter has better SNR than CWMF if input image has random noise and the improved synthesis algorithm can reduce the iteration time. We used frequency selective JTC to solve the problem of the optical alignment and eliminate the autocorrelation and crosscorrelation between each input image.

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The characteristics and optimal modeling of input source for optical device using thin film filter in optical telecommunication network (광통신용 박막필터형 광소자 분석을 위한 최적화 모델링과 특성분석)

  • 김명진;이승걸
    • Korean Journal of Optics and Photonics
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    • v.14 no.3
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    • pp.306-311
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    • 2003
  • In this paper, we modeled the incident beam in order to analyze and evaluate the optical thin film device for wavelength division multiplexing in optical telecommunication network. As applied ray tracing method to the optical path, we were compared the accuracy of coupling efficiency simulated by two modeling methods. In the results of sinulation, ceil modeling method was preferred to annual modeling method in micro-optic device because of accuracy for coupling efficiency and Gaussian intensity distribution. In the results of optimal simulation for optical device using thin film filter, the distance (d1) between optical fiber and GRIN lens, the distance (d2) between GRIN lens and thin film filter and the coupling efficiency were 0.24 mm, 0.25 mm and -0.11 ㏈ respectively. As d2 was displaced at 0.25 mm and d1 was varied in order to evaluate the optimal value, d1 and maximum coupling efficiency were 0.24 mm and -0.35㏈, respectively. Then the results of experiment were corresponded to that of optimal simulation by cell modeling and it was possible to analyze the performance for optical device using thin film filter by the simulation.

Experimental Outdoor Visible Light Data Communication Systems with Optical Filter (광필터를 이용한 실험적 실외 가시광 통신 시스템)

  • Kim, Yong-Hyeon;Chung, Yeon-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.8
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    • pp.1840-1846
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    • 2014
  • An experimental outdoor optical wireless data communication system with an optical filter in the presence of sunlight or artificial light is presented. For the efficient blocking of light noise outdoors, we employ an optical filter made of microlouver film on the top of the photo diode. This filter is designed to block any light noise incident from an angle higher than $30^{\circ}$ on the assumption that light noise does not face the photo diode horizontally. Outdoor experiments daytime with the optical filtering have been conducted. The experimental results demonstrate that the optical filter effectively blocks nearly all light noise incident from the specified angle or higher and more than 90% of the transmitted data packets are successfully received. The proposed outdoor visible light data communication can thus facilitate a practical free space outdoor optical wireless data transmission.