• Journal of the Optical Society of Korea
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• 제16권1호
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• pp.1-5
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• 2012

This paper describes a 150-Mb/s monolithic optical receiver for plastic optical fiber link using a standard CMOS technology. The receiver integrates a photodiode using an N-well/P-substrate junction, a pre amplifier, a post amplifier, and an output driver. The size, PN-junction type, and the number of metal fingers of the photodiode are optimized to meet the link requirements. The N-well/P-substrate photodiode has a 200-${\mu}m$ by 200-${\mu}m$ optical window, 0.1-A/W responsivity, 7.6-pF junction capacitance and 113-MHz bandwidth. The monolithic receiver can successfully convert 150-Mb/s optical signal into digital data through up to 30-m plastic optical fiber link with -10.4 dBm of optical sensitivity. The receiver occupies 0.56-$mm^2$ area including electrostatic discharge protection diodes and bonding pads. To reduce unnecessary power consumption when the light is not over threshold or not modulating, a simple light detector and a signal detector are introduced. In active mode, the receiver core consumes 5.8-mA DC currents at 150-Mb/s data rate from a single 3.3 V supply, while consumes only $120{\mu}W$ in the sleep mode.

• ETRI Journal
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• 제9권2호
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• pp.24-35
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• 1987

A Design and Fabrication of 565 Mbit/s Optical Fiber Transmission Link We calculated the transfer functions of optical channel components and formulated the optimum transfer function of optical receiver for optical transmission to show a design rule of fiber optical link for digital transmission. And we evaluated various causes of sensitivity degradation to determine the receiver specification. Also we fabricated and demonstrated a 565Mbit/s single mode fiber optic link, 27km, to show the practicality of designed fiber optic link. The output power of the transmitter was above -3dBm, and the sensitivity of the optical receiver was -37.8dBm which is the same value we expected. Also the dynamic range was more than 25dB.

• 대한전자공학회논문지SD
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• 제41권1호
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• pp.47-52
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• 2004

본 논문에서는 FTTH에 적용하기 적합한 넓은 입력 다이나믹 레인지와 낮은 비트 에러율을 갖는 CMOS 광수신기의 설계를 제안한다. 트랜스임피던스 전치증폭기의 PMOS 피드백 저항을 자신의 출력 신호의 크기에 따라 제어하여 100Mbps까지 60dB의 입력 다이나믹 레인지를 얻었다. 듀티 에러를 최소화시키기 위해 전류 거울 형태의 자동 바이어스 조절 회로를 설계하였다. 2-폴리, 3-메탈, 0.6um CMOS 공정 파라미터를 사용하여 회로 시뮬레이션을 수행하였다. 설계된 수신기는 5V의 전원을 사용할 때 100Mbps에서 130mW 이하의 전력 소비를 보였다.

• Ocean Systems Engineering
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• 제8권1호
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• pp.33-39
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• 2018

The paper presents a numerical underwater channel model developed in MATLAB for estimating the optical link budget between a light emitting diode (LED) based optical transmitter and a photo diode (PD) receiver when operated in the harbor, coastal and deep waters locations in the Bay of Bengal. The water samples are collected at different locations in the Bay of Bengal using a water sampler during an offshore research cruise. The optical attenuation, the main inherent parameter determining the range of the optical communication link is identified for the different waters using an underwater irradiance measurement system in the laboratory. The identified parameters are applied to the numerical model and found that a 10 W LED and a photo diode based system can provide the optical budget required for a horizontal underwater communication range of about 0.5, 14 and 35 m in the harbor, coastal and deep waters locations respectively. By increasing the transmitter power to 50 W, the operating range of the communication link could be increased up to 53 m in deep water locations in the Bay of Bengal.

• 한국정보통신학회논문지
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• 제16권10호
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• pp.2293-2302
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• 2012

단일 모드 광섬유의 그룹 속도 분산과 자기 위상 변조에 의해 왜곡된 파장 분할 다중 신호의 효율적인 보상을 위한 새로운 광전송 링크 기술을 제안하였다. 제안된 전송 링크는 WDM 송신이나 수신단 근처에 광 위상 공액기(OPC; optical phase conjugator)가 위치하고 각 중계 구간의 SMF 길이와 RDPS(residual dispersion per span)가 인위적으로 분포하는 구조이다. 시스템 성능을 개선하여 유효 입사 전력 범위와 유효 전체 잉여 분산 (NRD; net residual dispersion)을 늘릴 수 있는 최적의 링크 구조는 OPC가 WDM 수신단에 가깝게 위치하고 후치 보상(postcompensation)에 의해 NRD를 결정하고 중계 구간이 증가할수록 SMF 길이와 RDPS를 점진적으로 감소시키는 링크라는 것을 확인하였다.

• 한국통신학회논문지
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• 제33권12A호
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• pp.1251-1260
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• 2008

Diffuse wireless optical communication offers more robust optical links in terms of coverage and shadowing than line-of-sight links. However, traditional diffuse wireless infrared (IR) transceiver systems are more susceptible to multi-path distortion and great power decrease, which results in limiting high-speed performance. Multi-beam is an effective technique to compensate for multi-path distortion in a wireless infrared environment. The goal of this paper is to analyze the transmission characteristics by replacing traditional diffuse system (TDS) which contains single wide angle transmitter and single element receiver by system consisting of three-beam transmitter and non-imaging receiver (TNS) attached with compound parabolic concentrator (CPC). In the simulation, we use the recursive model developed by Barry and Kahn and build the scenario based on 10 different cases which have been listed in Table 1. Moreover, we also check the reliability of the TNS diffuse link channel by BER test on the basis of different receiver positions and room sizes. The simulation results not only show the basic transmission characteristics of TNS diffuse link, but also are references to design more efficient and reliable indoor infrared transmission systems.

• 전자공학회논문지A
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• 제30A권4호
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• pp.28-39
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• 1993

In the international BISDN used satellite, the laser that has large BW has to be used as a carrier for transmitting a lot of visual, vocal, and data information. Interoptical satellite communication has now developed in theoretical and practical aspects. But the optical communication, between satellite and earth station, is hindered by atmospheric absorption, scattering, and turbulence. In this paper, it was supposed that 1Gbps information was transmitted by binary FSK and 50mW AlGaAs semiconductor laser was used as a optical source in the satellite communication link between geosynchronous orbit satellite and earth station. We analyzed the BER and the entire diameter of the noncoherently combined optical heterodyne receiver as el evation angle, and determined the number of the optical heterodyne rece ivers, which is necessary for the BER of the receiver to be less than 10$^{-9}$ by computer simulation under the clear weather condition. It is shown that the BER and the number of the optical heterodyne receivers decrease as the elevation angle increases. In the region used the same number of the optical heterodyne receivers, it is shown that the entire diameter of the receiver increases but the BER decreases as the elevation angle increases.

• ETRI Journal
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• 제35권2호
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• pp.245-252
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• 2013

In this work, we study the physical layer solutions for 10-gigabit-capable passive optical networks (PONs), particularly for an optical link terminal (OLT) including a 10-Gbit/s electroabsorption modulated laser (EML) and a 2.5-Gbit/s burst mode receiver (BM-Rx) in a novel bidirectional optical subassembly (BOSA). As unique features, a bidirectional mini-flat package and a 9-pin TO package are developed for a 10-gigabit-capable PON OLT BOSA composed of a 1,577-nm EML and a 1,270-nm avalanche photodiode BM-Rx, including a single-chip burst mode integrated circuit that is integrated with a transimpedance and limiting amplifier. In the developed prototype, the 10-Gbit/s transmitter and 2.5-Gbit/s receiver characteristics are evaluated and compared with the physical media dependent (PMD) specifications in ITU-T G.987.2 for XG-PON1. By conducting the 10-Gbit/s downstream and 2.5-Gbit/s upstream transmission experiments, we verify that the developed 10-gigabitcapable PON PMD prototype can operate for extended network coverage of up to a 40-km fiber reach.

• 한국광학회지
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• 제29권2호
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• pp.77-84
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• 2018

본 연구에서 서울, 부산, 대전의 5년치 날씨 정보를 활용하여 우리나라 옥외 무선 광통신 시스템의 링크 가용성을 이론적으로 분석하였다. 이를 위하여 기상 상태와 시계(visibility)를 이용하여 대기의 흡수와 산란이 유발하는 광전력 감쇠를 계산하였다. 또한 날씨 정보를 활용하여 신틸레이션에 의한 수신 광전력 변화를 예측하였다. 대기의 흡수 및 산란에 의한 광전력 손실과 신틸레이션에 의한 광전력 변화가 서로 무관하다는 가정 하에 수신 광전력과 수신 감도를 비교하여 링크 가용성을 도출하였다. 분석결과 10 dBm 송신기 출력과 7 cm 수광 직경을 가진 수신기를 사용한 3.5 km 시스템의 링크 가용성은 대전에서 95% 이상으로 예측되었다. 부산과 서울의 경우 대전보다 열악한 시계로 인하여 낮은 링크 가용성을 보였다.

• International Journal of Internet, Broadcasting and Communication
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• 제14권3호
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• pp.63-68
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• 2022

Two wavelength reconfigurable optical nodes are designed. One for 20km or shorter link length, and the other for up to 60km link length. While the first one requires no dispersion compensation, the latter needs dispersion compensation fiber included in the node, which requires additional optical amplifier to compensate the insertion loss of DCF. We calculate all the optical path losses in both cases using the typical value of optical components in the market to see the feasibility of the designed optical node. The minimum received power in the node is calculated to be -21.5dBm without DCF and -12.5dBm with DCF, respectively. These received powers are above the receiver sensitivity both for OC-48 and OC-192 according to the previous work.