• Title/Summary/Keyword: Optical communications

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대만의 광산업 시장 동향

  • Jeong, U-Geum
    • Photonics industry news
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    • s.34
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    • pp.12-17
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    • 2006
  • 대만은 광산업 분야를 OE(Optoelectronics Components, FPD(Flat Panel Display), Optical Storage, Optical Lens Components & Laser Applications, OFC(Optical Fiber Communications, Optical Input & Output Devices 등 6개 대분류로 나누고 있으며 수년간 중점적으로 육성해 온 분야는 OE 및 FPD와 관련이 큰 LED 분야이다.

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Image processing technique for Optical Camera Communication (OCC에서의 이미지 처리 기술)

  • Nguyen, Trang;Le, Nam-Tuan;Jang, Yeong Min
    • Journal of Satellite, Information and Communications
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    • v.9 no.3
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    • pp.47-52
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    • 2014
  • This paper introduces the Optical Camera Communications (OCC) using image processing technique. The architecture and operation of OCC system are given. To enhance data rate which is limited by sampling operation of commercial 30fps camera, multi colors transmission technique is employed, leading to the importance of color image processing technique. Multi color encoding and image processing based decoding will be proposed in the paper.

Enhancement of free spectral range in the resonance peaks in a long period fiber grating by controlling clad mode material dispersion (광섬유 클래딩 모드의 분산 특성 조절에 의한 장주기 격자 내에서의 공명 피크의 free spectral range 향상)

  • Jeong, Hoon;Oh, K.
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.02a
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    • pp.72-73
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    • 2000
  • Optical fiber gratings have been intensively studied for applications in optical fiber communications and sensor systems due to their all-fiber configuration, low insertion loss, low cost, and high flexibility. Especially, cladding mode coupling fiber devices such as long period gratings (LPG) and acousto-optic tunable filters (AOTF) have been developed as a gain equalization filter in erbium doped fiber amplifier (EDFA) for wavelength division multiplexing (WDM) systems$^{(1-2)}$ . (omitted)

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Effect of Pump Wavelength on Gain Spectra for Single-pumped Fiber Optical Parametric Amplifiers

  • Fan, Weiwei;Watekar, Pramod R.;Han, Won-Taek
    • Proceedings of the Optical Society of Korea Conference
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    • 2009.10a
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    • pp.343-344
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    • 2009
  • Pump wavelength dependence of the gain spectra was investigated by simulating the model of single-pumped fiber optical parametric amplifiers (FOPAs). Conditions for the single-pumped FOPAs having broad bandwidths with relatively large gains were optimized and the gain bandwidth was found to be as large as 146.4 nm when signal power and pump power were 316 nW and 7 W, respectively.

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Generation of Coherent Sub-Terahertz Carrier with Phase Stabilization for Wireless Communications

  • Yoshimizu, Yasuyuki;Hisatake, Shintaro;Kuwano, Shigeru;Terada, Jun;Yoshimoto, Naoto;Nagatsuma, Tadao
    • Journal of Communications and Networks
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    • v.15 no.6
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    • pp.569-575
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    • 2013
  • In this paper, we present a photonic approach for generating highly stable coherent sub-terahertz (THz) signals for wireless communications. As proof-of-concept we transmit data at 100 GHz carrier frequency using on-off keying modulation and heterodyne detection. The sub-THz carrier signals are generated by photo-mixing two optical carrier signals at different frequencies, extracted from an optical frequency comb. We introduce a novel system to stabilize the phase of the optical carrier signals. Error-free transmission is successfully achieved up to a bit rate of 8.5 Gbit/s at 100 GHz.

Efficient Power-Saving 10-Gb/s ONU Using Uplink Usage-Dependent Sleep Mode Control Algorithm in WDM-PON

  • Lee, Han Hyub;Kim, Kwangok;Lee, Jonghyun;Lee, Sangsoo
    • ETRI Journal
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    • v.35 no.2
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    • pp.253-258
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    • 2013
  • We propose and demonstrate an efficient power-saving optical network unit (ONU) based on upstream traffic monitoring for 10-Gb/s wavelength division multiplexed passive optical networks (WDM-PONs). The power-saving mode controller uses a ${\mu}$-processor and traffic monitoring modules followed by the proposed power-saving processes to operate the sleep mode ONU. The power consumption of the ONU is effectively reduced from 19.3 W to 6.4 W when no traffic from the users is detected. In addition, we design a power-saving mechanism based on a cyclic sleep mode operation to allow a connectivity check between the optical line terminal and ONU. Our calculation results show that the WDM-PON ONU reduces the power consumption by around 60% using the proposed mechanism.

Experiments of Free-Space Optical Communication for Optical Ground Station (광통신 지상국 구축을 위한 자유공간 광통신 실험)

  • Taewoo Kim;Wonseok Kang;Sang Hoon Oh;Yong-sun Park;Jung-Hoon Kim
    • Journal of Space Technology and Applications
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    • v.4 no.1
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    • pp.74-85
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    • 2024
  • As the limitations of conventional radio communications between satellites and the ground become apparent, various experiments are being conducted around the world to overcome them with space laser communication. In this study, we address the development of our own optical communications terminal (OCT) and optical ground station (OGS) and the experiments of free-space optical communication (FSOC) using them. Using a 30 mm-diameter OCT and a 250 mm-diameter portable OGS telescope, as well as commercial 10 Gbps SFP+ modules and media converters, we successfully transmitted and received 4K high-definition multimedia interface (HDMI) signals through 1,550 nm optical laser beam. The transmission and reception distances of the experiment were 3, 9, and 20 km, respectively, and the received signal strength at each distance was +6.1, -2.8, and -10.9 dBm, respectively. It was demonstrated that the 4K HDMI video lasted for over 10 minutes.

New Type of White-light LED Lighting for Illumination and Optical Wireless Communication under Obstacles

  • Choi, Su-il
    • Journal of the Optical Society of Korea
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    • v.16 no.3
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    • pp.203-209
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    • 2012
  • Visible light communications (VLC) use modern solid-state light-emitting diodes (LEDs) to broadcast information. Emerging white-light LEDs allow the combination of lighting and optical wireless communication in one optical source. In this paper, a new LED lighting design using one-chip-type white LEDs is proposed for efficient illumination and optical wireless communications under the existence of several obstacles. Lighting and communication performance are analyzed to show the effectiveness of the proposed LED lighting. Specifically, the signal-to-noise ratio considering intersymbol interference and the bit-error rate of variable pulse position modulation (VPPM) with dimming control are considered.

Optical Wireless Remote Control Using Indoor LED Lightings (LED 실내조명을 이용한 광무선 원격제어)

  • Sohn, Kyung-Rak;Sohn, Chang-Woo
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.8
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    • pp.1111-1116
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    • 2012
  • At present, indoor optical wireless communications using LED lightings has been widely studied. The combination of this technology to the low voltage powerline grid installed in each home makes an efficient method for fulfilling the premise of broadband access for home networking. In this paper, white LEDs were used for both illumination and remote-control, so that information can be broadcast within a room for control the optical wireless systems. We implemented a model car to evaluate the performance of optical wireless remote-control. The requirement for levels of illumination suitable for communication were investigated and applied to design the test-bed. In spite of limitation of line-of-sight communications, it will open up new applications to the optical wireless remote control system in an electromagnetic interference region.