• Title/Summary/Keyword: EDFA

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Gain bandwidth characteristics of erbium-doped Fiber amplifiers for long-haul transmissions (에르븀 첨가 광섬유 증폭기의 장거리 전송에 따른 이득 평탄화 특성)

  • 정희상;이동한;정윤철;안성준;조흥근
    • Korean Journal of Optics and Photonics
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    • v.9 no.3
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    • pp.181-185
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    • 1998
  • Gain characteristic of concatenated erbium-doped fiber amplifiers(EDFA) are studied with a recirculating EDFA loop. For a non-flat gain EDFA, the 3 dB gain bandwidth was reduced to 6 nm after the 20th EDFA. However, for an optimized gain flattened EDFA, in a simple configuration, the 5 dB gain bandwidth was found to be 9nm, even after the 100th EDFA, corresponding to 8000km transmission. This results suggest that the simple optimized flat gain amplifier could be a good candidate for ultra-long distance wavelength division multiplexed transmissions.

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Analysis of EDFA (Erbium Doped Fiber Amplifier) for Fiber Optic Transmission System (광전송 시스템에서의 어븀 첨가 광섬유 증폭기에 대한 분석)

  • Kim, Ik-Sang;Ryu, Whang
    • The Journal of Engineering Research
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    • v.2 no.1
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    • pp.103-111
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    • 1997
  • EDFA (Erbium Doped Fiber Amplifier) is widely used to compensate the loss in fiber optic transmission system. The characteristics of EDFA are investigated by analyzing the mechanism amplifying the optical power of an input with several factors to obtain the criteria for designing EDFA. When it is used in fiber optic transmission system, signal to noise characteristics in the receiver is deteriorated due to the spontaneous emission noise of EDFA. We investigate the operating conditions of EDFA to reduce BER (Bit Error Rate).

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Investigation of Pump Wavelength Dependence of Long-Wavelength-Band Erbium-Doped Fiber Amplifier using 1530nm-Band Pump (L 대역 EDFA 특성의 펌프 파장 의존성에 관한 연구)

  • Choi, Bo-Hun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.7
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    • pp.1249-1255
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    • 2008
  • 1530nm band has been studied as pump wavelength for long-wavelength-band erbium-doped fiber amplifier (L-band EDFA). The pump source is built using a tunable light source and cascaded conventional-band (C-band) EDFA. The L-band EDFA uses a forward pumping scheme. Within the 1530nm band, 1545nm pump demonstrates 0.45dB/mW gain coefficient, which is twice better than that of conventional 1480nm pumped EDFA. The noise figure of 1530nm pump is at worst 6.36dB, which is 0.75dB higher than that of 1480nm pumped EDFA. Such high gain coefficient indicates that the L-band EDFA consumes low power.

Gain flattening of erbium-doped fiber amplifiers by using an AOTF for long-haul WDM optical transmissions (파장분할방식 장거리 광전송을 위한 음향광학필터를 이용한 에르븀 첨가 광섬유 증폭기의 이득 평탄화)

  • 안성준;정희상;이동한
    • Korean Journal of Optics and Photonics
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    • v.9 no.6
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    • pp.413-416
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    • 1998
  • We have flattened the gain of EDFA by using a long-period FBG filter and AOTF's. The gain and optical SNR characteristics of the gain-flattened EDFA in long-haul transmission been evaluated in a recirculating EDFA loop. The gain variation was less than 4.6 dB and the optical SNR was higher than 14 dB over 20-nm wavelength range when the optical signal went through the EDFA as many as 200 times. These results indicate that this gain-flattened EDFA is applicable for ultra long-haul WDM optical transmissions over 8000 km.

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Gain improvement of double-pass two-stage EDFA by using band-rejection filter (필터에 의한 이중경로 2단 EDFA의 이득 향상)

  • 손익부;백장기;이남권;권형우;송재원
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.02a
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    • pp.142-143
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    • 2003
  • EDFA의 이득(gain)과 잡음지수(noise figure)는 매우 중요한 특성 중의 하나이다. 전송 시스템에서 필연적으로 발생하는 ASE 잡음을 제거하는 것이 중요하다. EDFA의 중간에 필터(filter)와 아이솔레이터(isolator)를 삽입하여 불필요한 ASE를 제거함으로써 이득과 잡음지수를 향상시킬 수 있으며, 기존의 단일경로(single-pass) EDFA에서 필터의 위치가 40-60% 근처에서 이득과 잡음지수 향상이 가장 크게 된다. 그러나, 거울(mirror)을 사용하여 증폭 효율을 높인 이중경로(double-pass) EDFA에서 필터에 의한 이득 향상에 관한 연구발표는 아직까지 없다. (중략)

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DYNAMIC CHARACTERISTICS OF GAIN-CLAMPED L-BAND EDFA WITH BI-DIRECTIONAL PUMPS (양방향 고정이득 L-BAND EDFA의 응답 특성)

  • IkSangKim
    • Journal of the Korean Geophysical Society
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    • v.4 no.4
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    • pp.297-311
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    • 2001
  • The gain-clamped EDFA has been developed to eliminate the output power change of WDM surving channels to occur with added or dropped channels, which degrades the performance of WDM optical network. It maintains the constant gain of surviving channels when WDM channels are added or dropped in a network amplifying node. In this paper, the bi-directionally pumped gain-clamped EDFA is implemented to compensate the change of the input power by a lasing. The results show that the lasing of a short wavelength and backward propagation is the optimal condition to minimize the transient response of surviving channels in terms of the overshoot and gain saturation due to the inhomogeneous broadening effect.

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Dynamic Characteristics of Gain-Clamped L-band EDFA with Bi-directional Pumps (양방향 펌프구조 고정이득 L-band EDFA의 과도응답 특성)

  • Kim, Ik-Sang
    • The Journal of Engineering Research
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    • v.5 no.1
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    • pp.119-133
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    • 2004
  • The gain-clamped EDFA has been developed to eliminate the output power change of WDM surviving channels to occur with added or dropped channels, which degrades the performance of EDM optical network. It maintains the constant gain of surviving channels when WDM channels are added or dropped in a network amplifying node. In this paper, the bi-directionally pumped gain-clamped EDFA is implemented to compensate the change of the input power by a lasing. The results show that the alsing of a short wavelength and backward propagation is the optimal condition to minimize the transient response of surviving channels in terms of the overshoot and gain saturation sue to the inhomogeneous broadening effect.

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Characteristics of Random Jitter in Analog Fiber-Optic Links Employing a Mach-Zehnder Modulator and an EDFA (마하-젠더 광 변조기와 EDFA를 사용한 아날로그 광통신 링크의 랜덤 지터 특성)

  • Yoon, Young-Min;Lee, Min-Young;Shin, Jong-Dug;Kim, Boo-Gyoun
    • Journal of IKEEE
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    • v.13 no.4
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    • pp.96-102
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    • 2009
  • We investigate the characteristics of RJ (random jitter) in an analog fiber-optic link employing a MZM (Mach-Zehnder modulator) and an EDFA (Erbium-doped fiber amplifier). RJ has been measured using two methods, one of which derived from the noise spectrum of a RF spectrum analyzer and the other from the histogram data of a sampling oscilloscope. If the optical power and/or the RF power input to the MZM increase, RJ decreases due to the output signal power increase. For the optical link without EDFA, the minimum RJ is about 1 ps at an RF power of 10 dBm and an optical power of 8 dBm measured using the noise spectrum method. For the optical link with an EDFA, RJ decreases toward a jitter floor as the EDFA gain increases. If the gain increases further, it has been observed that RJ increases from the minimum. If the EDFA gain is fixed, RJ is smaller for the case of larger optical input power. As the EDFA gain increases, RJ reduction rate becomes greater for the case of lower optical input power.

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Efficient pulse amplification in a two-stage EDEA with a bandpass filter (2단 광섬유 증폭기를 이용한 효율적인 고출력 펄스 증폭)

  • Kim, Byung-Jun;Lee, Han-Hyub;Choi, Hyun-Beom;Lee, Dong-Han;Kim, Dae-Yun;Kwon, Il-Bum
    • Korean Journal of Optics and Photonics
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    • v.14 no.2
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    • pp.146-149
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    • 2003
  • Nanosecond pulses are efficiently amplified by a two-stage EDFA. The EDFA employs an optical bandpass filter between stages to remove the amplified spontaneous emission of the first EDFA that strongly saturates the gain of the second EDFA. The peak power of the amplified output pulse is 83 W when that of the input pulse of 10 ㎱width and 100 $mutextrm{s}$ period is 1 ㎽.

Packet Error Rate Characteristics of an Optical Packet Switching Node with an Optical Packet Address Processor Using an EDFA Preamplifier (광 패킷 어드레스 처리기에 EDFA 전치 증폭기를 사용한 광 패킷 교환 노드의 패킷 오율 특성)

  • 윤찬호;백승환;신종덕
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.7
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    • pp.1777-1784
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    • 1998
  • The packet error rates of an optical packet switching node with an optical address processor using an EDFA in order to detect M-ary correlation pulses at a fiber-optical delay line matched filter output have been evaluated. Effects of A PIN diode NEP, the gain and noise figure of the EDFA, and the bandwidth of an optical filter on the packet error rate of the switching node have been compared. There is negligible error rate change depending upon the variation of the PIN diode NEP and the EDFA gain. If the bandwidth of the optical filter is below 10 times of the data rate, there is no appreciable effect on the error rate. If the noise figure of the EDFA increases, however, the power penalty increases as much as the noise figure increment at all the bit rates and for address code sets considered in this work.

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