JPH0389644A - Transmission method for wavelength multiplex optical signal - Google Patents
Transmission method for wavelength multiplex optical signalInfo
- Publication number
- JPH0389644A JPH0389644A JP1226940A JP22694089A JPH0389644A JP H0389644 A JPH0389644 A JP H0389644A JP 1226940 A JP1226940 A JP 1226940A JP 22694089 A JP22694089 A JP 22694089A JP H0389644 A JPH0389644 A JP H0389644A
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- 230000003287 optical effect Effects 0.000 title claims abstract description 69
- 230000005540 biological transmission Effects 0.000 title claims abstract description 30
- 238000000034 method Methods 0.000 title claims description 16
- 230000008054 signal transmission Effects 0.000 claims description 14
- 238000004891 communication Methods 0.000 claims description 7
- 230000001427 coherent effect Effects 0.000 claims description 6
- 238000001514 detection method Methods 0.000 claims description 5
- 239000000835 fiber Substances 0.000 abstract description 22
- 239000013307 optical fiber Substances 0.000 abstract description 11
- 229910052691 Erbium Inorganic materials 0.000 abstract description 2
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 abstract description 2
- 238000000926 separation method Methods 0.000 description 7
- 230000003321 amplification Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 238000003199 nucleic acid amplification method Methods 0.000 description 6
- 239000004065 semiconductor Substances 0.000 description 5
- 230000035945 sensitivity Effects 0.000 description 5
- 230000001419 dependent effect Effects 0.000 description 3
- 230000002457 bidirectional effect Effects 0.000 description 2
- 238000005773 Enders reaction Methods 0.000 description 1
- 238000001069 Raman spectroscopy Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
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Abstract
Description
【発明の詳細な説明】
(産業上の利用分野)
本発明は波長多重信号伝送方法に関し、特に光増幅器を
用いる波長多重信号伝送方法に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a wavelength multiplexed signal transmission method, and more particularly to a wavelength multiplexed signal transmission method using an optical amplifier.
(従来の技術)
波長多重信号伝送は伝送容量を拡大するために有効な手
段のひとつと考えられている。この波長多重信号伝送で
は送受信部で光の合分波を行なうからそこで合分波損失
を生じる。この合分波損失および伝送路損失を補償する
手段としては光増幅器の利用が有効である。(Prior Art) Wavelength multiplexing signal transmission is considered to be one of the effective means for expanding transmission capacity. In this wavelength multiplexed signal transmission, since light is multiplexed and demultiplexed in the transmitting and receiving section, multiplexing and demultiplexing loss occurs there. The use of an optical amplifier is effective as a means to compensate for this multiplexing/demultiplexing loss and transmission line loss.
ここで光増幅器としては、半導体光増幅器、ファイバラ
ンマ増幅器、希土類ドープファイバ増幅器等があるが特
にエルビウム(Er)ドープファイバ増幅器は光ファイ
バとの低損失結合が可能、無偏光依存、半導体レーザ励
起が可能等の特徴を有しており注目されている(たとえ
ば野山3により1989年電子情報通信学会春季全国大
会で発表された論文(c−622)rl、49μm半導
体レーザ励起エルビウムドープファイバの光増幅特性」
)。Examples of optical amplifiers here include semiconductor optical amplifiers, fiber rammer amplifiers, and rare earth-doped fiber amplifiers, but erbium (Er)-doped fiber amplifiers in particular are capable of low-loss coupling with optical fibers, are non-polarized light dependent, and can be pumped by semiconductor lasers. (For example, a paper (c-622) rl presented at the 1989 Spring National Conference of the Institute of Electronics, Information and Communication Engineers by Noyama 3, Optical amplification characteristics of a 49 μm semiconductor laser-pumped erbium-doped fiber. ”
).
(発明が解決しようとする課題)
Erドープファイバ増幅器を用いる場合、その利得の波
長依存性が問題となる。第2図はErドープファイバ増
幅器の典型的な利得特性を示した図である。(Problems to be Solved by the Invention) When using an Er-doped fiber amplifier, the wavelength dependence of its gain becomes a problem. FIG. 2 is a diagram showing typical gain characteristics of an Er-doped fiber amplifier.
第2図から明らかなようにErドープファイバ増幅器で
は波長1,53μmから1.56μmの広波長帯域にわ
たって20dB以上の利得が得られるがその利得の大き
さには大きな波長依存性がある。従って、上記の波長帯
で波長多重信号伝送を行なおうとする場合には波長によ
って得られる利得が異なり各波長によって得られる許容
伝送路損失が異なってしまうという欠点があった。As is clear from FIG. 2, the Er-doped fiber amplifier can obtain a gain of 20 dB or more over a wide wavelength band of 1.53 μm to 1.56 μm, but the gain has a large wavelength dependence. Therefore, when attempting to perform wavelength multiplexed signal transmission in the above-mentioned wavelength band, there is a drawback that the gain obtained differs depending on the wavelength, and the allowable transmission line loss obtained differs depending on the wavelength.
そこで本発明の目的は、波長によって利得が異なる光増
幅器を用いて波長多重伝送を行なう場合でも各波長にお
ける許容伝送路損失を等しく光増幅器の増幅帯域を有効
に利用できる波長多重光信号増幅伝送方法を提供するこ
とにある。Therefore, an object of the present invention is to provide a wavelength multiplexing optical signal amplification transmission method that can effectively utilize the amplification band of the optical amplifier by equalizing the allowable transmission line loss at each wavelength even when performing wavelength division multiplexing transmission using optical amplifiers with different gains depending on the wavelength. Our goal is to provide the following.
(課題を解決するための手段)
本発明による波長多重光信号増幅伝送方法の第1の態様
では、波長多重された複数の信号光を光増幅器でブース
タ増幅または中継増幅して伝送する波長多重信号伝送方
法において、光増幅器の利得帯域特性に基づいて各波長
帯の利得に比例して各信号光の信号帯域を設定して伝送
することにより、各信号光に割り当てられる許容伝送路
損失を等しくして伝送している。(Means for Solving the Problems) In a first aspect of the wavelength-multiplexed optical signal amplification and transmission method according to the present invention, a wavelength-multiplexed signal is transmitted after booster amplifying or repeating amplification of a plurality of wavelength-multiplexed signal lights using an optical amplifier. In the transmission method, the allowable transmission line loss assigned to each signal light is equalized by setting the signal band of each signal light in proportion to the gain of each wavelength band based on the gain band characteristics of the optical amplifier. is being transmitted.
また、第2のR様では波長多重された複数の信号光を光
増幅器でブースタ増幅または中継増幅して伝送する波長
多重信号伝送方法において、光増幅器の利得帯域特性に
基づいて各波長帯の利得に比例して波長多重分離のため
の損失を割り当てることにより、各信号光に割り当てら
れる許容伝送路損失を等しくして伝送している。In addition, in the second R, in a wavelength multiplexed signal transmission method in which multiple wavelength-multiplexed signal lights are booster-amplified or relay-amplified and transmitted using an optical amplifier, the gain of each wavelength band is determined based on the gain band characteristics of the optical amplifier. By allocating the loss for wavelength multiplexing and demultiplexing in proportion to , the allowable transmission line loss allocated to each signal light is made equal and transmitted.
更に第3の態様では波長多重された複数の信号光を光増
幅器でブースタ増幅または中継増幅して伝送する波長多
重信号伝送方法において、光増幅器の利得帯域特性に基
づいて利得の大きな波長帯の信号光は直接検波系で伝送
し、利得の小さな波長帯の信号光はコヒーレント通信系
で伝送することにより、波長多重された各信号先割り当
てられる許容伝送路損失を等しくして伝送している。Furthermore, in a third aspect, in a wavelength multiplexed signal transmission method in which a plurality of wavelength-multiplexed signal lights are booster-amplified or relay-amplified and transmitted using an optical amplifier, a signal in a wavelength band with a large gain is determined based on the gain band characteristics of the optical amplifier. Light is transmitted using a direct detection system, and signal light in a wavelength band with small gain is transmitted using a coherent communication system, thereby making the allowable transmission path loss assigned to each wavelength-multiplexed signal equal to each other.
〈作用)
通常の光通信システムで実現される受信感度は信号速度
が10倍になると感度は10倍〜12倍程度悪くなる。<Function> When the signal speed increases by 10 times, the reception sensitivity realized in a normal optical communication system deteriorates by about 10 to 12 times.
従って、たとえば光増幅器を用いる波長多重光信号伝送
システムの2波長間で光増幅器の利得が10dB異なる
場合、利得の低いほうの波長の信号速度を利得が高いほ
うの波長の約1710にしておけばこのシステムにおい
て両波長で実現される許容伝送路損失をほぼ等しくする
ことができる。Therefore, for example, if the gain of the optical amplifier differs by 10 dB between two wavelengths in a wavelength division multiplexing optical signal transmission system using an optical amplifier, the signal speed of the wavelength with lower gain should be set to about 1710 of that of the wavelength with higher gain. In this system, the allowable transmission path losses achieved at both wavelengths can be made approximately equal.
また、両波長間で同じ伝送速度の信号を伝送する場合で
も信号光の合分波を行なうときの合分波損失が両波長間
で異なるようにすれば両波長の許容伝送路損失を等しく
することが可能である。たとえば、送信側で合波器とし
て分岐比が10:lの光フアイバカプラを用いれば両波
長間で光増幅器利得が10dB異なっていても、両波長
でほぼ等しい許容伝送路損失を実現できる。In addition, even when transmitting signals with the same transmission speed between both wavelengths, if the multiplexing and demultiplexing loss when performing multiplexing and demultiplexing of signal light is made different between both wavelengths, the allowable transmission path loss for both wavelengths can be made equal. Is possible. For example, if an optical fiber coupler with a branching ratio of 10:l is used as a multiplexer on the transmitting side, even if the optical amplifier gains differ by 10 dB between the two wavelengths, approximately the same allowable transmission line loss can be achieved for both wavelengths.
さらにここでコヒーレント光通信の利用を考える。コヒ
ーレント光通信は通常の直接検波系に比べその光受信感
度が10dB以上改善されることが知られている。従っ
て、たとえば光増幅器の利得が10dB異なっている場
合には利得の大きな波長帯を直接検波系で、利得の小さ
な波長帯をコヒーレント系で利用することによって両波
長帯でほCX等しく許容伝送路損失を実現することが可
能になる。Furthermore, consider the use of coherent optical communication. It is known that coherent optical communication improves optical reception sensitivity by more than 10 dB compared to a normal direct detection system. Therefore, for example, if the gains of optical amplifiers differ by 10 dB, by using the wavelength band with large gain in the direct detection system and the wavelength band with small gain in the coherent system, the allowable transmission line loss will be equal in CX in both wavelength bands. becomes possible.
(実施例)
第1図は本発明の第1の実施例を説明するためのブロッ
ク図である。(Embodiment) FIG. 1 is a block diagram for explaining a first embodiment of the present invention.
本実施例では波長1.536μmの第1の光源1と波長
1.552μmの第2の光源2を用いて波長多重伝送を
行なっている。In this embodiment, wavelength multiplex transmission is performed using a first light source 1 with a wavelength of 1.536 μm and a second light source 2 with a wavelength of 1.552 μm.
第1と第2の光源1.2には分布帰還型の半導体レーザ
を用いており第1の光源1は第1の信号源3によりI
G b / sで、第2の光源2は第2の信号源4によ
り100 M b / sでそれぞれ変調されている。Distributed feedback semiconductor lasers are used for the first and second light sources 1.2, and the first light source 1 is
G b /s, and the second light sources 2 are each modulated by the second signal sources 4 at 100 M b /s.
第1と第2の光源1.2からの出力は光合波器5で合波
された後、長尺の第1の光フアイバ増幅器7により増幅
される。このErドープファイバ増幅器7は波長1.4
9μmの第3の光源8により励起されており、波長1.
536μmでは30dB、1.552μmでは20dB
の利得が得られている。The outputs from the first and second light sources 1.2 are combined by an optical multiplexer 5 and then amplified by a long first optical fiber amplifier 7. This Er-doped fiber amplifier 7 has a wavelength of 1.4
It is excited by a third light source 8 with a wavelength of 9 μm and a wavelength of 1.
30dB at 536μm, 20dB at 1.552μm
gains have been obtained.
E’rドープファイバ増幅器7で増幅された信号光は長
尺の第2の光ファイバ9を伝搬した後、波長分離フィル
タ10により波長1.536μmと波長1.552μm
が分離された後、それぞれ第1、第2の光受信器11.
12で受信される。各受信信号は第1、第2の復調回路
13.14により復調され、信号の再生が行われる。After the signal light amplified by the E'r-doped fiber amplifier 7 propagates through the long second optical fiber 9, it is separated by the wavelength separation filter 10 into a wavelength of 1.536 μm and a wavelength of 1.552 μm.
After being separated, the first and second optical receivers 11.
It is received at 12. Each received signal is demodulated by first and second demodulation circuits 13 and 14, and the signal is reproduced.
ここで波長1.536μm、IGb/sの信号光に対す
る光受信感度は一38dBmであり波長1.552μm
、100Mb/sの信号光の光受信感度は一48dBM
であった。Here, the optical reception sensitivity for a signal light of IGb/s with a wavelength of 1.536 μm is -38 dBm and a wavelength of 1.552 μm.
, the optical reception sensitivity of 100 Mb/s signal light is -48 dBM.
Met.
本実施例では光合波器5で合波された後の波長1.53
6μmおよび1.552μmの両信号光の強度は、とも
にOdBmであり1100kの第1の光ファイバ6を伝
搬した後、Erドープファイバ増幅器7の入力レベルは
ともに一25dBmとなっている。ここで2つの信号光
はそれぞれ波長に応じた利得(30dB、20dB)を
受けたのちふたたび150kmの第2の光ファイバ9を
伝搬してそれぞれ第1、第2の光受信器11゜12で受
信される。In this embodiment, the wavelength after being combined by the optical multiplexer 5 is 1.53.
The intensities of the 6 μm and 1.552 μm signal lights are both OdBm, and after propagating through the 1100k first optical fiber 6, the input level of the Er-doped fiber amplifier 7 is -25 dBm. Here, the two signal lights each receive a gain (30 dB, 20 dB) according to their wavelength, and then propagate again through the 150 km second optical fiber 9 and are received by the first and second optical receivers 11 and 12, respectively. be done.
Erドープファイバ増幅器7の出力から第1と第2の光
受信器11.12までの損失マージンは波長1.536
μm、1.552μmともに43dBであり、第2の光
ファイバ9の損失37dB、波長分離フィルタ10の損
失1dBを考慮しても両波長とも5dBのマージンをも
って信号を受信することができた。The loss margin from the output of the Er-doped fiber amplifier 7 to the first and second optical receivers 11.12 is 1.536 wavelength.
μm and 1.552 μm were both 43 dB, and even considering the loss of 37 dB of the second optical fiber 9 and the loss of 1 dB of the wavelength separation filter 10, it was possible to receive the signal with a margin of 5 dB for both wavelengths.
本実施例では、2つの波長を同方向に伝送する場合を述
べたが同様のことは双方向伝送にあてはめることができ
る。双方向伝送では下り回線に大容量が要求され上り回
線は比較的低容量で良い場合が多い、従って、下り回線
に波長1.536μmを上り回線に波長1.552μm
をあてはめることでErドープファイバ増幅器7の増幅
帯域を有効に利用することが可能になる。In this embodiment, the case where two wavelengths are transmitted in the same direction has been described, but the same thing can be applied to bidirectional transmission. In bidirectional transmission, a large capacity is required for the downlink, while a relatively low capacity is often sufficient for the uplink. Therefore, the wavelength of 1.536 μm is used for the downlink, and the wavelength of 1.552 μm is used for the uplink.
By applying , it becomes possible to effectively utilize the amplification band of the Er-doped fiber amplifier 7.
また、本実施例で1.552μm帯にコヒーレント光通
信システムを導入することにより両波長ともIGb/S
の信号を伝送するようにすることも可能である。たとえ
ばIGb/s CPFSK光ヘテロゲイン検波システ
ムでは一46dBmの光受信感度の実現が可能である。In addition, by introducing a coherent optical communication system in the 1.552 μm band in this embodiment, both wavelengths can be used as IGb/S.
It is also possible to transmit the following signals. For example, an IGb/s CPFSK optical heterogain detection system can achieve an optical receiving sensitivity of -46 dBm.
このシステムを波長1.552μm帯に導入すればこの
波長帯でもI G b / sで1.536μm帯と同
距離の伝送が可能となる。If this system is introduced in the 1.552 μm wavelength band, it will be possible to transmit IG b/s over the same distance as in the 1.536 μm band in this wavelength band.
第3図は本発明の第2の実施例を説明するためのブロッ
ク図である。FIG. 3 is a block diagram for explaining a second embodiment of the present invention.
本実施例においても光増幅器としてはErドープファイ
バ増幅器7を用いている0本実施例では波長1.536
μm帯で400 M b / sの第1の信号光群20
の16波を第1の光多重素子22により10GHz間隔
で多重し、また波長1.552μm帯で同じ< 400
M b / sの第2の信号光群21の8波を第2の
光多重素子23により10GHz間隔で多重し、これら
をさらに光合波器5で合波している。In this embodiment as well, the Er-doped fiber amplifier 7 is used as the optical amplifier. In this embodiment, the wavelength is 1.536.
400 Mb/s first signal light group 20 in μm band
The first optical multiplexing element 22 multiplexes the 16 waves of
The eight waves of the second signal light group 21 of Mb/s are multiplexed at 10 GHz intervals by the second optical multiplexing element 23, and these are further multiplexed by the optical multiplexer 5.
ここでErドープファイバ増幅器7の入力レベルは、光
多重時の損失の差により1.536μmでは一15dB
m、1552μmでは一11dBmであった。Erドー
プファイバ増幅器7では波長1.536μm帯では帯域
内平均30dB、1.552μm帯では帯域内平均22
dBの利得が得られた。−増幅された信号光群は光ファ
イバ9を伝搬した後、波長分離フィルタ10で波長1.
536μm帯と1.552μm帯に分離される。それぞ
れの波長帯の信号光群はそれぞれマツハツエンダ−干渉
計により構成される第1、第2の光周波数分離素子24
.25で各波長の信号に分離され第1.第2の光受信器
群26.27で受信される。Here, the input level of the Er-doped fiber amplifier 7 is -15 dB at 1.536 μm due to the difference in loss during optical multiplexing.
m, it was -11 dBm at 1552 μm. In the Er-doped fiber amplifier 7, the average within the band is 30 dB in the wavelength band of 1.536 μm, and the average within the band is 22 dB in the wavelength band of 1.552 μm.
A gain of dB was obtained. - After the amplified signal light group propagates through the optical fiber 9, it passes through the wavelength separation filter 10 at wavelength 1.
It is separated into a 536 μm band and a 1.552 μm band. Signal light groups in each wavelength band are transmitted through first and second optical frequency separation elements 24 each formed by a Matsuhatsu Ender interferometer.
.. 25, the signal is separated into signals of each wavelength. It is received by the second optical receiver group 26 and 27.
本実施例において波長1゜536μm帯は1.552μ
m帯に比べErドープファイバ増幅器7で8dB大きな
利得が得られているが波長多重数が多いため光多重素子
22、光周波数分離素子24で1.552μm帯に比べ
て8dB大きな損失を受けている。このため、システム
の全体でのマージンは両波長帯で等しくなっている。従
って、本実施例によりBrドープファイバ増幅器7の帯
域を有効に利用した波長多重伝送が可能になる。In this example, the wavelength 1°536 μm band is 1.552 μm.
Compared to the m band, an 8 dB larger gain is obtained in the Er-doped fiber amplifier 7, but due to the large number of wavelengths multiplexed, the optical multiplexing element 22 and the optical frequency separation element 24 suffer an 8 dB larger loss compared to the 1.552 μm band. . Therefore, the overall margin of the system is equal in both wavelength bands. Therefore, this embodiment enables wavelength division multiplexing transmission by effectively utilizing the band of the Br-doped fiber amplifier 7.
本発明には以上の実施例の他にも様々な変形例が考えら
れる。たとえば実施例ではErドープファイバ増幅器7
を利用した場合について記載したが、光増幅器としては
利得に波長依存性のある他の光増幅器たとえばラマン増
幅器等にも利用することができる。In addition to the above-described embodiments, various modifications of the present invention can be considered. For example, in the embodiment, the Er-doped fiber amplifier 7
Although the case where the optical amplifier is used has been described, the optical amplifier can also be used in other optical amplifiers whose gain is wavelength dependent, such as a Raman amplifier.
また、半導体増幅器の場合でもゲインピーク波長とその
波長と大きくずれた波長で波長多重を行なう場合には両
波長間に利得差が生じるので本発明を適用することがで
きる。Further, even in the case of a semiconductor amplifier, when wavelength multiplexing is performed using a gain peak wavelength and a wavelength that is significantly different from that wavelength, a gain difference occurs between the two wavelengths, so the present invention can be applied.
また、本発明の3つの方法を組み合わせて、すなわち各
チャンネル間の信号速度、合分波損失受信方式を組み合
わせてシステムにおける各波長多重信号に対する許容伝
送路損失を等しくするようにしてもよい。Further, the three methods of the present invention may be combined, that is, the signal speed between each channel and the multiplexing/demultiplexing loss reception method may be combined to equalize the allowable transmission line loss for each wavelength multiplexed signal in the system.
(発明の効果)
以上に詳しく述べたように本発明を用いれば、利得に波
長依存性がある光増幅器を用いる場合でもその利得帯域
の全てを有効に使って波長多重送信システムを構成する
ことができる。(Effects of the Invention) As described in detail above, by using the present invention, even when using an optical amplifier whose gain is wavelength dependent, it is possible to configure a wavelength division multiplexing transmission system by effectively using the entire gain band. can.
第1図は本発明の第1の実施例を説明するためのブロッ
ク図J第2図はErドープファイバ増幅器の利得特性を
示した図、第3図は本発明の第2の実施例を説明するた
めのブロック図である。
1.2・・・光源、5・・・光合波器、6,9・・・光
ファイバ、7・・・Erドープファイバ増幅器、1o・
・・波長分離フィルタ、11.12・・・光受信器、2
0゜21・・・信号光群、22.23・・・光多重素子
、24゜25・・・光周波数分離素子、26.27・・
・光受信器群。Fig. 1 is a block diagram for explaining the first embodiment of the present invention. Fig. 2 is a diagram showing the gain characteristics of an Er-doped fiber amplifier. Fig. 3 is a block diagram for explaining the second embodiment of the present invention. FIG. 1.2... Light source, 5... Optical multiplexer, 6, 9... Optical fiber, 7... Er-doped fiber amplifier, 1o.
... Wavelength separation filter, 11.12 ... Optical receiver, 2
0°21... Signal light group, 22.23... Optical multiplexing element, 24°25... Optical frequency separation element, 26.27...
・Optical receiver group.
Claims (3)
タ増幅または中継増幅して伝送する波長多重信号伝送方
法において、前記光増幅器の利得帯域特性に基づいて各
波長帯の利得にほぼ比例して前記各信号光の信号帯域を
設定して伝送することにより、前記各信号光に割り当て
られる許容伝送路損失の等しい伝送を行なうことを特徴
とする波長多重光信号伝送方法。(1) In a wavelength multiplexed signal transmission method in which a plurality of wavelength-multiplexed signal lights are booster-amplified or relay-amplified and transmitted using an optical amplifier, the gain of each wavelength band is approximately proportional to the gain based on the gain band characteristics of the optical amplifier. A wavelength multiplexing optical signal transmission method, characterized in that by setting and transmitting a signal band of each of the signal lights, transmission is performed with equal allowable transmission line loss assigned to each of the signal lights.
タ増幅または中継増幅して伝送する波長多重信号伝送方
法において、前記光増幅器の利得帯域特性に基づいて各
波長帯の利得にほぼ比例して波長多重分離のための損失
を割り当てることにより、前記各信号光に割り当てられ
る許容伝送路損失の等しい伝送を行なうことを特徴とす
る波長多重光信号伝送方法。(2) In a wavelength multiplexed signal transmission method in which a plurality of wavelength-multiplexed signal lights are booster-amplified or relay-amplified and transmitted using an optical amplifier, the gain of each wavelength band is approximately proportional to the gain based on the gain band characteristics of the optical amplifier. 1. A wavelength multiplexing optical signal transmission method, characterized in that by allocating losses for wavelength multiplexing and demultiplexing to each signal light, transmission is performed with equal allowable transmission line losses assigned to each of the signal lights.
タ増幅または中継増幅して伝送する波長多重信号伝送方
法において、前記光増幅器の利得帯域特性に基づいて利
得の大きな波長帯の信号光は直接検波系で伝送し、利得
の小さな波長帯の信号光はコヒーレント通信系で伝送す
ることにより、波長多重された各信号光に割り当てられ
る許容伝送路損失の等しい伝送を行なうことを特徴とす
る波長多重光信号伝送方法。(3) In a wavelength multiplexed signal transmission method in which a plurality of wavelength-multiplexed signal lights are booster-amplified or relay-amplified and transmitted using an optical amplifier, the signal light in a wavelength band with a large gain is determined based on the gain band characteristics of the optical amplifier. A wavelength characterized in that by transmitting signal light in a direct detection system and transmitting signal light in a wavelength band with small gain through a coherent communication system, transmission with equal allowable transmission path loss assigned to each wavelength-multiplexed signal light is performed. Multiplex optical signal transmission method.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1226940A JPH0389644A (en) | 1989-08-31 | 1989-08-31 | Transmission method for wavelength multiplex optical signal |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1226940A JPH0389644A (en) | 1989-08-31 | 1989-08-31 | Transmission method for wavelength multiplex optical signal |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0389644A true JPH0389644A (en) | 1991-04-15 |
Family
ID=16852995
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1226940A Pending JPH0389644A (en) | 1989-08-31 | 1989-08-31 | Transmission method for wavelength multiplex optical signal |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0389644A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03129330A (en) * | 1989-10-14 | 1991-06-03 | Mitsubishi Cable Ind Ltd | Optical communication system |
JPH05122159A (en) * | 1991-05-13 | 1993-05-18 | Internatl Business Mach Corp <Ibm> | Method of improving ratio of signal to noise of transmission signal and optical interconnection system |
US5436760A (en) * | 1993-07-14 | 1995-07-25 | Nec Corporation | Optical fiber amplifier with gain equalizing circuit |
US5745283A (en) * | 1995-08-23 | 1998-04-28 | Fujitsu Limited | Method and apparatus for controlling optical amplifier used for optically amplifying wavelength-division multiplexed signal |
US5808785A (en) * | 1993-12-27 | 1998-09-15 | Nec Corporation | Optical fiber amplifier and optical transmission system using the same |
-
1989
- 1989-08-31 JP JP1226940A patent/JPH0389644A/en active Pending
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03129330A (en) * | 1989-10-14 | 1991-06-03 | Mitsubishi Cable Ind Ltd | Optical communication system |
JPH05122159A (en) * | 1991-05-13 | 1993-05-18 | Internatl Business Mach Corp <Ibm> | Method of improving ratio of signal to noise of transmission signal and optical interconnection system |
US5436760A (en) * | 1993-07-14 | 1995-07-25 | Nec Corporation | Optical fiber amplifier with gain equalizing circuit |
US5808785A (en) * | 1993-12-27 | 1998-09-15 | Nec Corporation | Optical fiber amplifier and optical transmission system using the same |
US5745283A (en) * | 1995-08-23 | 1998-04-28 | Fujitsu Limited | Method and apparatus for controlling optical amplifier used for optically amplifying wavelength-division multiplexed signal |
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