• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.105-108
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• 2002

We report on the polarization-insensitive design and fabrication of an arrayed waveguide gratings (AWG's) using sol-gel derived silica glass films formed on fused silica substrates to provide cheap and stable tools for better design. An arrayed-waveguide grating multiplexer with raised structure is fabricated in order to effect polarization sensitivity. Since polarization is usually not known after propagation in an optical fiber. passive WDM components such as monolithic wavelength demultiplexer have to be polarization insensitive. Here, we observed that polarization have effect on crosstalk of output spectrum in arrayed-waveguide grating

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.78-79
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• 2000

재구성이 가능한 광 크로스-커넥트(optical cross connect)는 전광 네트워크를 구성하기 위한 핵심소자 중의 하나이다. 일반적인 구조의 파장분배기는 공간분할 스위치(space division switch)를 두 쌍의 파장 다중화기(multiplexer)와 역다중화기(demultiplexer)의 가운데에 삽입하여 구현된다$^{(1)}$ . 최근에, 광섬유 브래그 격자와 광스위치 쌍을 직렬 연결하여 재구성이 가능한 광 크로스-커넥트가 제안되었다$^{(2)}$ . 그러나, 이 구조는 광신호에 따라 광섬유 브래그 격자에 반사되면서 겪는 광스위치에 의한 삽입손실이 다르다는 문제점이 있다. 이러한 문제를 해결하기 위하여 본 논문에서는 한 쌍의 파장 다중화기/역다중화기와 파장가변 광섬유 브래그 격자를 이용한 새로운 구조의 광 크로스-커넥트를 제안하고자 한다. 또한, 제안된 구조는 일반적인 구조의 파장분배기에 비해 파장 다중화기/역다중화기의 개수를 반으로 줄일 수 있는 장점이 있다. (중략)

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.8B
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• pp.1048-1056
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• 2001

파장분할 다중 광전송 시스템으로의 적용을 위한 홀로그래픽 다채널 역다중화기를 제안하고, 소자 특성에 대한 이론적 예측 및 실험결과를 제시하였다. LiNbO3:Fe 결정에 다중 홀로그래픽 부피 격자채널을 기록하기 위해 각도 다중 기록 및 노출시간 계획을 적용하였으며, 노출시간 계획에 recycling 기법을 적용해 각 채널의 균일도를 향상시켰다. 본 논문에서 제안한 방식을 실험적으로 입증하기 위해 1590nm 파장영역에서 0.8nm 채널 간격을 갖는 8채널 역다중화기를 설계하고 해석하였으며, 실험결과 각 채널은 0.8∼0.92%의 회절효율, 0.38∼0.45nm의 3dB 통과대역, 0.7∼0.89nm의 채널간격 및 -26.98dB 이상의 채널 누화 억제 특성을 관찰하였다.

• Korean Journal of Optics and Photonics
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• v.8 no.6
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• pp.506-509
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• 1997

A novel narrowband wavelength bandpass filter with a large side-lobe suppression was proposed in vertical coupler structure using coupling variation in propagation direction. Combination of a half sinusoidal distributed and a slow coupling schmes was used for narrow bandwidth and small side-lobes. Simulation showed 1.5 nm passband at 1.5507 $\mu\textrm{m}$ and the side-lobes were suppressed more than 20 dB which is two times larger than that of a constant coupling filter. A monolithic two-channel wavelength demultiplexer was proposed and theoretically investigated.

• Journal of IKEEE
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• v.14 no.4
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• pp.283-290
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• 2010

This study is on the design of 10Gbps CMOS receiver circuits for fiber-optic communication. The receiver is made up of a photodiode, a transimpedance amplifier, a limiting amplifier, an equalizer, a clock and data recovery loop circuit, and a demultiplexer or demux with some auxiliary circuits including I/O circuits. Various wideband or high-speed circuit techniques are harnessed to realize a feasible, effective, and reliable receiver for a SONET fiber-optic standard, OC-192.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.158-159
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• 2000

본 논문에서는 BK7 유리 기판에 Ag$^{+}$-$Na^{+}$ 이온교환법을 이용하여 1.31/1.55$mu extrm{m}$ 방향성 광결합기형 역다중화기를 제작하여 특성을 평가하였다. BK7에 이온교환법을 이용하여 도파로를 제작할 경우 0.2dB/cm 이하의 전파손실을 유지할 수 있으며 또한 도파로의 굴절율 분포가 단일모드 광섬유와 매우 유사하여 광섬유와 광소자 사이의 접합면에서 발생하는 접합손실을 줄일 수 있다 또한 BK7을 이용하면 도파로를 제작하였을 때 복굴절 현상이나 편광 의존성이 적어서 수동 소자 제작에 유용하다는 장점이 있다$^{(1 3)}$ . (중략)

• Journal of Broadcast Engineering
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• v.22 no.6
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• pp.755-764
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• 2017

In this paper, we design transmitter and receiver structures for a $2{\times}2$ multiple-input multiple-output (MIMO) in ATSC 3.0 systems and analyze the performance of the $2{\times}2$ MIMO system. In the ATSC 3.0 MIMO systems, spatial diversity and multiplexing gains can be obtained using the spatial demultiplexer and precoder. In this paper, we present the structures of the transmitter and receiver for ATSC 3.0 MIMO systems. Also, we present performance results of the $2{\times}2$ MIMO system through computer simulations.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.6
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• pp.599-605
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• 2003

A dual-mode asymmetric canonical filter is widely used in an input demultiplexer for satellite transponder. This paper deals with a simple synthesis method fur an asymmetric canonical filter. The coupling matrix of an asymmetric canonical filter is obtained by applying plane rotation technique to the coupling matrix of a symmetric canonical filter. This paper gives a list of pivots and rotation angles to obtain the coupling matrix of asymmetric canonical structure filters. The coupling matrix of 8th and 10th order asymmetric canonical filter is obtained by this proposed method. It is shown that the frequency response of asymmetric canonical filter is identical to that of symmetric canonical filter.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.5
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• pp.27-36
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• 2004

In this paper, we propose the ethernet Inter-Processor Communication (IPC) network architecture and 10gigabit ethernet frame multiplex/demultiplexer architecture for the edge switch system based on Linux that has 10 Gigabit Ethernet (10Gigabit Ethernet) port with 72Gbps capacities. we discuss the ethernet IPC with ethernet switch and we propose design and implementation of ethernet Inter-Processor Communication (IPC) network architecture and multiple gigabit ethernet frame rnultiplexing/demultiplexing scheme to handle 10gigabit ethernet frame instead of using 10gigabit network processor. And then ethernet Inter-Processor Communication (IPC) network architecture and 10gigabit ethernet frame MUX/DMUX architecture is designed verified and implemented.

• Journal of the Optical Society of Korea
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• v.13 no.3
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• pp.354-360
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• 2009

We investigate theoretically the tolerance of 40 Gbps phase-modulated (PM) duobinary signals using a vestigial sideband (VSB) filter on impairments which occurred in dense wavelength-division multiplexing (DWDM) systems, compared to the conventional duobinary signals. Our simulation results show that PM duobinary signals can't have the gain on the spectral efficiency achieved by utilizing the VSB filtering technique. In order to increase the spectral efficiency, they indispensably require to be transmitted at the optimum bandwidth of multiplexer (MUX) and demultiplexer (DEMUX) since they are susceptible to inter-channel crosstalk. It is also shown that the PM duobinary modulation format has a large tolerance on self-phase modulation (SPM) and cross-phase modulation (XPM) under the condition which MUX and DEMUX have been tuned at an optimum bandwidth; it has 1.2 dB power penalty at the fiber launching power (FLP) of 15 dBm and the channel spacing of 50 GHz.