JP3062204B2 - Optical amplifier - Google Patents

Optical amplifier

Info

Publication number
JP3062204B2
JP3062204B2 JP1267246A JP26724689A JP3062204B2 JP 3062204 B2 JP3062204 B2 JP 3062204B2 JP 1267246 A JP1267246 A JP 1267246A JP 26724689 A JP26724689 A JP 26724689A JP 3062204 B2 JP3062204 B2 JP 3062204B2
Authority
JP
Japan
Prior art keywords
optical fiber
light
pumping
signal light
amplification
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
JP1267246A
Other languages
Japanese (ja)
Other versions
JPH03127885A (en
Inventor
正隆 中沢
康郎 木村
紘幸 田中
俊和 御前
実 吉田
正明 森澤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Cable Industries Ltd
Nippon Telegraph and Telephone Corp
Original Assignee
Mitsubishi Cable Industries Ltd
Nippon Telegraph and Telephone Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Cable Industries Ltd, Nippon Telegraph and Telephone Corp filed Critical Mitsubishi Cable Industries Ltd
Priority to JP1267246A priority Critical patent/JP3062204B2/en
Publication of JPH03127885A publication Critical patent/JPH03127885A/en
Application granted granted Critical
Publication of JP3062204B2 publication Critical patent/JP3062204B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/09—Processes or apparatus for excitation, e.g. pumping
    • H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • H01S3/094003—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light the pumped medium being a fibre
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06754—Fibre amplifiers

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Optics & Photonics (AREA)
  • Lasers (AREA)
  • Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)

Description

【発明の詳細な説明】 ＜産業上の利用分野＞ 本発明は、信号光を誘導放出効果を利用して直接増幅
する光ファイバを備えた光増幅器に関する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical amplifier having an optical fiber for directly amplifying signal light by using a stimulated emission effect.

＜従来の技術＞ 現在実用化されている光ファイバ通信システムにおい
ては、光ファイバの損失による光信号の減衰を補償する
ために、所定距離ごとに光中継器が設置されている。従
来の光中継器では、光信号をフォトダイオード等によっ
て電気信号に変換して電子増幅器によって信号を増幅し
た後、半導体レーザ（LD）等によって光信号に変換して
光ファイバ伝送路に再び送り出すようになっている。し
かしながら、このような構成の光中継器では、光信号を
一旦電気信号に戻した後、再び光信号に変換する必要が
あるために、雑音や光ファイバとの接続損失が多く、さ
らに、装置全体が大型化するなどの難点がある。<Prior Art> In an optical fiber communication system currently in practical use, optical repeaters are installed at predetermined distances in order to compensate for attenuation of an optical signal due to loss of an optical fiber. In a conventional optical repeater, an optical signal is converted into an electric signal by a photodiode or the like, the signal is amplified by an electronic amplifier, and then converted into an optical signal by a semiconductor laser (LD) and transmitted to an optical fiber transmission line again. It has become. However, in the optical repeater having such a configuration, it is necessary to convert an optical signal into an electrical signal once and then convert it into an optical signal again. However, there is a drawback such as an increase in size.

そのため、近年は、光中継器として、誘導放出効果も
つ光ファイバを利用した光増幅器を用いることが考えら
れている。この光増幅器Ampは、第２図に示すように、
希土類元素（たとえばEr）をドープした増幅用光ファイ
バａと、この増幅用光ファイバａを励起する半導体レー
ザ等の励起光源ｂとを備えており、光ファイバを介して
伝送されてくる信号光と励起光源ｂからの励起光とを合
波器ｃで混合してこれらの光を増幅用光ファイバａに入
射する。そして、励起光によって増幅用光ファイバａに
ドープした希土類元素のイオンを高いエネルギ準位に励
起し、信号光を誘導放出によって増幅する。なお、ｄは
増幅用光ファイバａの接続部である。Therefore, in recent years, it has been considered to use an optical amplifier using an optical fiber having a stimulated emission effect as an optical repeater. This optical amplifier Amp, as shown in FIG.
An amplification optical fiber a doped with a rare earth element (for example, Er), and an excitation light source b such as a semiconductor laser for exciting the amplification optical fiber a are provided. The pumping light from the pumping light source b is mixed by the multiplexer c, and these lights enter the amplifying optical fiber a. Then, the ions of the rare earth element doped into the amplification optical fiber a are excited to a high energy level by the excitation light, and the signal light is amplified by stimulated emission. In addition, d is a connection part of the amplification optical fiber a.

この光増幅器Ampを使用すれば、光信号を直接増幅で
きるので低雑音であり、また伝送用光ファイバとの結合
も良くて接続損失も少ないばかりか、装置の小型化、低
廉化を図ることができる等の利点を有する。If this optical amplifier Amp is used, the optical signal can be directly amplified, resulting in low noise, good coupling with the transmission optical fiber and low connection loss, as well as reduction in size and cost of the device. It has such advantages as possible.

＜発明が解決しようとする課題＞ ところで、光ファイバ通信システムにおいて、一つの
光中継器から次の光中継器までの伝送距離が長い場合に
は、信号光の減衰が大きくなるので、これを補償するた
めに、予め光中継器から出力する信号光のパワーをでき
るだけ高くしておく必要がある。<Problems to be Solved by the Invention> In an optical fiber communication system, if the transmission distance from one optical repeater to the next optical repeater is long, the attenuation of the signal light increases. Therefore, it is necessary to increase the power of the signal light output from the optical repeater as high as possible.

しかしながら、第２図に示した従来の光増幅器Ampで
は、単一の励起光源ｂによって増幅用光ファイバａを励
起しているだけなので、信号光の増幅率を高めるには自
と限界がある。However, in the conventional optical amplifier Amp shown in FIG. 2, since the amplification optical fiber a is only pumped by the single pumping light source b, there is a limit in increasing the amplification factor of the signal light.

信号光の増幅率をより一層高めるには、第３図に示す
ように、複数の光増幅器Amp1、Amp2を縦列接続し、初段
の励起光源b1と増幅用光ファイバa1とで信号光を一旦増
幅した後、引き続いて、次段の励起光源b2と増幅用光フ
ァイバa2とで信号光を更に増幅することが考えられる。In order to further increase the amplification factor of the signal light, as shown in FIG. 3, a plurality of optical amplifiers Amp 1 and Amp 2 are connected in cascade, and the signal is transmitted between the first-stage pump light source b 1 and the amplification optical fiber a 1. after once amplified light, subsequently, further amplifying is considered a signal light in the next stage of the pumping light source b 2 and the amplification optical fiber a 2.

しかし、この場合は、増幅用光ファイバa1、a2が各段
ごとに必要であり、また、各光増幅器Amp1、Amp2をそれ
ぞれ縦列接続する必要があるために、装置全体が大型化
するばかりか、コストアップになるなどの不具合があ
る。However, in this case, the amplification optical fibers a 1 and a 2 are required for each stage, and the optical amplifiers Amp 1 and Amp 2 need to be connected in cascade. In addition to the above, there are problems such as increased costs.

＜課題を解決するための手段＞ 本発明は、このような事情に鑑みてなされたものであ
って、小型かつ安価であるにもかかわらず、信号光を長
距離伝送に必要なパワーまで十分に増幅できる光増幅器
を得ることを目的とする。<Means for Solving the Problems> The present invention has been made in view of such circumstances, and despite being small and inexpensive, it is sufficient to transmit the signal light to the power required for long-distance transmission. An object is to obtain an optical amplifier that can be amplified.

そのため、本発明では、励起光によりエネルギ順位を
高めて誘導放出により信号光を増幅する増幅用光ファイ
バを備えた光増幅器において、次の構成を採る。For this reason, the present invention employs the following configuration in an optical amplifier including an amplification optical fiber for increasing the energy order by pumping light and amplifying signal light by stimulated emission.

すなわち、本発明の光増幅器では、増幅用光ファイバ
の入力側に、信号光の伝送方向に沿って励起光を入力す
る順入力励起手段を、増幅用光ファイバの出力側に、信
号光の伝送方向とは逆方向に沿って励起光を入力する逆
入力励起手段をそれぞれ配置するとともに、増幅用光フ
ァイバで増幅された信号光の強度を検出して前記逆入力
励起手段の励起光をフィードバック制御するフィードバ
ック制御手段を備えている。That is, in the optical amplifier of the present invention, the input side of the amplifying optical fiber is provided with a forward input pumping means for inputting the pumping light along the transmission direction of the signal light, and the signal light is transmitted to the output side of the amplifying optical fiber. The reverse input pumping means for inputting the pumping light along the direction opposite to the direction is arranged, and the intensity of the signal light amplified by the amplification optical fiber is detected to feedback-control the pumping light of the reverse input pumping means. Feedback control means.

＜作用＞ 増幅用光ファイバの入力側に設けられた順入力励起手
段からは、信号光の伝送方向に沿って励起光が入射され
る。また、増幅用光ファイバの出力側に設けられた逆入
力励起手段からは、信号光の伝送方向とは逆方向に沿っ
て励起光が入射される。<Operation> From the forward input pumping means provided on the input side of the amplification optical fiber, pumping light is incident along the signal light transmission direction. Also, from the reverse input pumping means provided on the output side of the amplification optical fiber, pumping light is incident along the direction opposite to the signal light transmission direction.

この場合、励起光が増幅用光ファイバに対して順逆い
ずれの方向から入力されようとも、増幅用光ファイバに
及ぼすポンピング作用は変わらない。したがって、増幅
用光ファイバは、これらの励起光によってそれぞれ励起
され、これに応じて信号光は、誘導放出効果によって２
重に増幅される。また、フィードバック制御手段によっ
て増幅用光ファイバで増幅された信号光の強度を検出し
て逆入力励起手段の励起光のみをフィードバック制御す
るので、常に安定した出力が得られ、しかも、順入力励
起手段の励起光を同時にフィードバック制御する場合と
比較して、制御系を簡素化できるのみならず、雑音指数
（NF）も低く抑えることができ良好な増幅特性を得るこ
とができる。In this case, the pumping action on the amplification optical fiber does not change regardless of whether the pumping light is input to the amplification optical fiber from the forward or reverse direction. Therefore, the amplification optical fiber is pumped by each of these pumping lights, and the signal light is accordingly excited by the stimulated emission effect.
It is heavily amplified. Further, since the feedback control means detects the intensity of the signal light amplified by the amplifying optical fiber and feedback-controls only the pump light of the reverse input pump means, a stable output is always obtained, and furthermore, the forward input pump means As compared with the case where the pump lights are simultaneously feedback controlled, not only the control system can be simplified, but also the noise figure (NF) can be suppressed low, and good amplification characteristics can be obtained.

＜実施例＞ 第１図は本発明に係る光増幅器の構成図である。同図
において、１は光増幅器の全体を示し、２はたとえば1.
55μｍの波長帯の信号光を誘導放出により増幅する増幅
用光ファイバである。この増幅用光ファイバ２は、たと
えば石英系ガラスコアの周囲に屈折率がこれよりも小さ
い石英系ガラスクラッドを設けるとともに、コアまたは
コアの外周部にEr、Nd等の希土類元素をドープして構成
されている。なお、このEr、Nd等の希土類元素にさらに
Yd、Al等の他の元素を同時にドープしてもよい。Embodiment FIG. 1 is a configuration diagram of an optical amplifier according to the present invention. In the figure, 1 indicates the entire optical amplifier, and 2 indicates, for example, 1.
This is an amplification optical fiber that amplifies signal light in the 55 μm wavelength band by stimulated emission. The amplification optical fiber 2 is configured by, for example, providing a silica-based glass clad having a smaller refractive index around a silica-based glass core and doping the core or the outer periphery of the core with a rare earth element such as Er or Nd. Have been. The rare earth elements such as Er and Nd
Other elements such as Yd and Al may be simultaneously doped.

４は増幅用光ファイバ２の入力側において、信号光の
伝送方向（図中左から右に向かう方向）に沿って、たと
えば1.48μｍの波長帯の励起光を入力する順方向励起手
段であって、増幅用光ファイバ２を励起する励起光を発
生する半導体レーザ（LD）等の励起光源６と、信号光と
励起光とを混合する合波器８とから構成される。10は増
幅用光ファイバ２の両端に設けられた光ファイバ接続部
である。また、12は増幅用光ファイバ２の出力側におい
て、信号光の伝送方向とは逆方向に沿って励起光を入力
する逆入力励起手段であって、たとえば1.48μｍの波長
帯の励起光を発生する半導体レーザ（LD）等の励起光源
14と、信号光と励起光とを混合する合波器16とから構成
される。18は増幅用光ファイバ２で増幅された信号光の
みを通過させて励起光を除くフィルタ、20はフィルタ18
を通過した信号光の一部を取り出す分波器である。Reference numeral 4 denotes a forward pumping means for inputting pumping light in a wavelength band of, for example, 1.48 μm on the input side of the amplification optical fiber 2 along the signal light transmission direction (direction from left to right in the figure). A pumping light source 6 such as a semiconductor laser (LD) for generating pumping light for pumping the amplification optical fiber 2 and a multiplexer 8 for mixing signal light and pumping light. Numeral 10 denotes optical fiber connecting portions provided at both ends of the optical fiber 2 for amplification. Reference numeral 12 denotes a reverse input pumping means for inputting pumping light at the output side of the amplifying optical fiber 2 in a direction opposite to the signal light transmission direction, for example, generating pumping light in a wavelength band of 1.48 μm. Pumping light source such as semiconductor laser (LD)
14 and a multiplexer 16 for mixing the signal light and the pump light. Reference numeral 18 denotes a filter that passes only the signal light amplified by the amplification optical fiber 2 and removes the pump light, and reference numeral 20 denotes a filter.
Is a duplexer that extracts a part of the signal light that has passed through.

21は増幅用光ファイバ２で増幅された信号光の強度を
検出して逆入力励起手段12の励起光をフィードバック制
御するフィードバック制御手段であって、分波器20で取
り出された増幅後の信号光の強度を検出する光検出器2
2、この光検出器22の検出出力を基準値と比較する比較
器24、および比較器24の出力に基づいて励起光源14の励
起光の出力強度を制御する制御器26から構成されてい
る。Numeral 21 denotes feedback control means for detecting the intensity of the signal light amplified by the amplification optical fiber 2 and performing feedback control of the pump light of the reverse input pump means 12. Photodetector 2 for detecting light intensity
2, a comparator 24 for comparing the detection output of the photodetector 22 with a reference value, and a controller 26 for controlling the output intensity of the excitation light of the excitation light source 14 based on the output of the comparator 24.

なお、28は接続用の光ファイバである。 Reference numeral 28 denotes a connection optical fiber.

次に、この光増幅器１の作用を説明する。 Next, the operation of the optical amplifier 1 will be described.

入力側と出力側の各励起光源６、14で発生された、各
1.48μｍ帯の励起光は、それぞれ合波器８、16を介して
増幅用光ファイバ２に入射される。増幅用光ファイバ２
には、Er、Nd等の希土類元素がドーピングされているの
で、これらの元素のイオンが励起光によって励起され
る。この場合、励起光が増幅用光ファイバ２に対して順
逆いずれの方向から入力されようとも、増幅用光ファイ
バ２に及ぼすポンピング作用は変わらない。したがっ
て、この状態で、たとえば1.55μｍ帯の信号光が増幅用
光ファイバ２に入射すると、この信号光が増幅用光ファ
イバ２中を進行する際に誘導放出によって増幅される。
そして、増幅された信号光がフィルタ18を通過して出力
される。また、励起光はフィルタ18で遮断される。Each of the input and output pump light sources 6, 14
Excitation light in the 1.48 μm band enters the amplification optical fiber 2 via the multiplexers 8 and 16, respectively. Optical fiber for amplification 2
Is doped with rare earth elements such as Er and Nd, and the ions of these elements are excited by the excitation light. In this case, the pumping action on the amplification optical fiber 2 does not change regardless of the direction in which the pumping light is input to the amplification optical fiber 2 in either the forward or reverse direction. Therefore, in this state, for example, when a signal light in the 1.55 μm band enters the amplification optical fiber 2, the signal light is amplified by stimulated emission when traveling through the amplification optical fiber 2.
Then, the amplified signal light passes through the filter 18 and is output. Further, the excitation light is blocked by the filter 18.

増幅された信号光の一部は、分波器20から光検出器22
に導かれてその信号強度が検出される。次いで、この光
検出器22の検出出力が比較器24で基準値と比較される。
この比較出力は制御器26に与えられるので、制御器26
は、比較器24の出力に応じて励起光源14から発生される
励起光の強度を制御する。これにより、増幅用光ファイ
バ２を励起するパワーが調整されるため、フィルタ18を
通過して取り出される信号光の出力強度が常に一定に保
たれる。Part of the amplified signal light is transmitted from the demultiplexer 20 to the photodetector 22.
And the signal strength is detected. Next, the detection output of the photodetector 22 is compared with a reference value by the comparator 24.
Since this comparison output is given to the controller 26, the controller 26
Controls the intensity of the excitation light generated from the excitation light source 14 according to the output of the comparator 24. As a result, the power for exciting the amplification optical fiber 2 is adjusted, so that the output intensity of the signal light extracted through the filter 18 is always kept constant.

このように、本実施例の光増幅器１では、入力側と入
力側に設けた各励起手段４、12によって増幅用光ファイ
バ２が２重に励起されるために、高出力が得られる。し
かも、出力側の励起光源14がフィードバック制御される
ため、常に安定した出力が得られるだけでなく、順入力
励起手段４の励起光を同時にフィードバック制御する場
合と比較して、制御系を簡素化できるのみならず、雑音
指数（NF）も低く抑えることができ良好な増幅特性を得
ることができる。As described above, in the optical amplifier 1 of the present embodiment, a high output is obtained because the amplification optical fiber 2 is double-pumped by the pumping means 4 and 12 provided on the input side and the input side. In addition, since the output side pumping light source 14 is feedback-controlled, not only a stable output is always obtained, but also the control system is simplified as compared with the case where the pumping light of the forward input pumping means 4 is simultaneously feedback-controlled. Not only can the noise factor (NF) be kept low, but also good amplification characteristics can be obtained.

＜発明の効果＞ 本発明によれば、一つの増幅用光ファイバに入射され
る信号光が、入力側と出力側からそれぞれ入射される励
起光によって２重に励起されるので、小型かつ安価であ
るにもかかわらず、信号光を長距離伝送に必要な十分な
パワーまで十分に増幅することができる。また、フィー
ドバック制御手段によって増幅用光ファイバで増幅され
た信号光の強度を検出して逆入力励起手段の励起光のみ
をフィードバック制御するので、常に安定した出力が得
られ、しかも、順入力励起手段の励起光を同時にフィー
ドバック制御する場合と比較して、制御系を簡素化でき
るのみならず、雑音指数（NF）も低く抑えることができ
良好な増幅特性を得ることができる。<Effects of the Invention> According to the present invention, the signal light incident on one amplification optical fiber is double-pumped by the pump light incident on each of the input side and the output side. Nevertheless, the signal light can be sufficiently amplified to a power sufficient for long-distance transmission. Further, since the feedback control means detects the intensity of the signal light amplified by the amplifying optical fiber and feedback-controls only the pump light of the reverse input pump means, a stable output is always obtained, and furthermore, the forward input pump means As compared with the case where the pump lights are simultaneously feedback controlled, not only the control system can be simplified, but also the noise figure (NF) can be suppressed low, and good amplification characteristics can be obtained.

【図面の簡単な説明】[Brief description of the drawings]

第１図は本発明の実施例に係る光増幅器の構成図、第２
図は従来の光増幅器の構成図、第３図は従来の他の光増
幅器の構成図である。 １……光増幅器、２……増幅用光ファイバ、４……入力
側励起手段、12……出力側励起手段、６、14……励起光
源、８、16……合波器、18……フィルタ、20……分波
器、21……フィードバック制御手段、22……光検出器、
24……比較器、26……制御器。FIG. 1 is a block diagram of an optical amplifier according to an embodiment of the present invention.
FIG. 1 is a configuration diagram of a conventional optical amplifier, and FIG. 3 is a configuration diagram of another conventional optical amplifier. DESCRIPTION OF SYMBOLS 1 ... Optical amplifier, 2 ... Amplifier optical fiber, 4 ... Input side pumping means, 12 ... Output side pumping means, 6, 14 ... Pumping light source, 8, 16 ... Coupler, 18 ... Filter, 20: duplexer, 21: feedback control means, 22: photodetector,
24 ... Comparator, 26 ... Controller.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 田中 紘幸 兵庫県伊丹市池尻４丁目３番地 三菱電 線工業株式会社伊丹製作所内 (72)発明者 御前 俊和 兵庫県伊丹市池尻４丁目３番地 三菱電 線工業株式会社伊丹製作所内 (72)発明者 吉田 実 兵庫県伊丹市池尻４丁目３番地 三菱電 線工業株式会社伊丹製作所内 (72)発明者 森澤 正明 兵庫県伊丹市池尻４丁目３番地 三菱電 線工業株式会社伊丹製作所内 (56)参考文献 特開 昭59−114883（ＪＰ，Ａ) 特開 昭59−86023（ＪＰ，Ａ) 特開 昭60−157279（ＪＰ，Ａ) 特開 昭59−10046（ＪＰ，Ａ) 特開 平２−157829（ＪＰ，Ａ) 特開 平３−44981（ＪＰ，Ａ) 特開 平３−139617（ＪＰ，Ａ) 特開 平３−71116（ＪＰ，Ａ) 特開 平３−62022（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H01S 3/10 H01S 3/06 - 3/07 G02F 1/35 H04B 10/00 - 10/28 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Tanaka 4-3 Ikejiri, Itami-shi, Hyogo Mitsubishi Electric Wire Industry Co., Ltd. Itami Works (72) Inventor Toshikazu Gozen 4-3, Ikejiri, Itami-shi, Hyogo Mitsubishi Electric Inside the Itami Works of the Wire Industry Co., Ltd. (72) Minoru Yoshida 4--3 Ikejiri, Itami-shi, Hyogo Mitsubishi Electric Corporation (72) Inventor Masaaki Morisawa 4-3-3 Ikejiri, Itami-shi, Hyogo Mitsubishi Electric (56) References JP-A-59-114883 (JP, A) JP-A-59-86023 (JP, A) JP-A-60-157279 (JP, A) JP-A 59-114 10046 (JP, A) JP-A-2-157829 (JP, A) JP-A-3-44981 (JP, A) JP-A-3-139617 (JP, A) JP-A-3-71116 (JP, A) JP Hei 3-62022 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) H01S 3/10 H01S 3/06-3/07 G02F 1/35 H04B 10/00-10/28

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】励起光によりエネルギ準位を高めて誘導放
出により信号光を増幅する増幅用光ファイバを備えた光
増幅器において、 前記増幅用光ファイバの入力側に、信号光の伝送方向に
沿って励起光を入力する順入力励起手段を、増幅用光フ
ァイバの出力側に、信号光の伝送方向とは逆方向に沿っ
て励起光を入力する逆入力励起手段をそれぞれ配置する
とともに、前記増幅用光ファイバで増幅された信号光の
強度を検出して前記逆入力励起手段の励起光のみをフィ
ードバック制御するフィードバック制御手段を備えるこ
とを特徴とする光増幅器。1. An optical amplifier comprising an amplification optical fiber for increasing an energy level by pumping light and amplifying a signal light by stimulated emission, wherein an input side of the amplification optical fiber is arranged along a transmission direction of the signal light. Forward input pumping means for inputting pumping light, and reverse input pumping means for inputting pumping light along the direction opposite to the signal light transmission direction on the output side of the amplifying optical fiber; An optical amplifier comprising feedback control means for detecting the intensity of the signal light amplified by the optical fiber for use in feedback control of only the pumping light of the reverse input pumping means.
JP1267246A 1989-10-13 1989-10-13 Optical amplifier Expired - Lifetime JP3062204B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1267246A JP3062204B2 (en) 1989-10-13 1989-10-13 Optical amplifier

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1267246A JP3062204B2 (en) 1989-10-13 1989-10-13 Optical amplifier

Publications (2)

Publication Number Publication Date
JPH03127885A JPH03127885A (en) 1991-05-30
JP3062204B2 true JP3062204B2 (en) 2000-07-10

Family

ID=17442168

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1267246A Expired - Lifetime JP3062204B2 (en) 1989-10-13 1989-10-13 Optical amplifier

Country Status (1)

Country Link
JP (1) JP3062204B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07318289A (en) * 1994-05-23 1995-12-08 Nippondenso Co Ltd Heat exchanger

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5910046A (en) * 1982-07-07 1984-01-19 Fujitsu Ltd Optical repeater
US4515431A (en) * 1982-08-11 1985-05-07 The Board Of Trustees Of The Leland Stanford Junior University Fiber optic amplifier
US4546476A (en) * 1982-12-10 1985-10-08 The Board Of Trustees Of The Leland Stanford Junior University Fiber optic amplifier
US4674830A (en) * 1983-11-25 1987-06-23 The Board Of Trustees Of The Leland Stanford Junior University Fiber optic amplifier
JPH0758377B2 (en) * 1988-12-12 1995-06-21 日本電信電話株式会社 Optical fiber type optical amplifier
GB2230912B (en) * 1989-04-22 1993-10-20 Stc Plc Optical amplifier gain control
JPH0344981A (en) * 1989-07-12 1991-02-26 Shimadzu Corp Optical fiber amplifier
US4963832A (en) * 1989-08-08 1990-10-16 At&T Bell Laboratories Erbium-doped fiber amplifier coupling device
US5058974A (en) * 1989-10-06 1991-10-22 At&T Bell Laboratories Distributed amplification for lightwave transmission system

Also Published As

Publication number Publication date
JPH03127885A (en) 1991-05-30

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