JPH0850208A - Dispersion compensator - Google Patents
Dispersion compensatorInfo
- Publication number
- JPH0850208A JPH0850208A JP6205948A JP20594894A JPH0850208A JP H0850208 A JPH0850208 A JP H0850208A JP 6205948 A JP6205948 A JP 6205948A JP 20594894 A JP20594894 A JP 20594894A JP H0850208 A JPH0850208 A JP H0850208A
- Authority
- JP
- Japan
- Prior art keywords
- dispersion
- optical fiber
- compensating optical
- dispersion compensating
- polarization
- 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.)
- Pending
Links
Landscapes
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
- Optical Communication System (AREA)
- Light Guides In General And Applications Therefor (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、光ファイバや半導体レ
ーザの波長分散を補償する光ファイバ型の分散補償器に
関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber type dispersion compensator for compensating for wavelength dispersion of an optical fiber or a semiconductor laser.
【０００２】[0002]
【従来の技術】半導体レーザ等の光をパルス信号で変調
し、光ファイバに入射させ、その光ファイバを伝送路と
して用いる通信方式が実用化されている。2. Description of the Related Art A communication system in which light from a semiconductor laser or the like is modulated with a pulse signal and incident on an optical fiber, and the optical fiber is used as a transmission line has been put into practical use.
【０００３】ところで、光ファイバは、通常、石英系ガ
ラスにより形成されており、この石英系ガラスの屈折率
は、光の波長が長いほど小さくなる。そのため、光ファ
イバは、周知の光の材料分散に起因して、光ファイバを
伝搬する光波の波長が長いほど、その光の伝搬速度が速
くなり、光波の波長が短いほど、その光の伝搬速度が遅
くなる、いわゆる正の分散特性（波長分散）を有するこ
とが知られている。そして、このような分散特性を有す
る光ファイバに、一般に、中心波長に対してある程度広
がりを有する半導体レーザの光を入射させた場合は、そ
の入射光のパルス幅に比べて、光ファイバを伝搬した後
の出射光のパルス幅が広くなる。By the way, the optical fiber is usually formed of silica glass, and the refractive index of the silica glass becomes smaller as the wavelength of light becomes longer. Therefore, due to the known material dispersion of light, an optical fiber has a higher propagation speed of light as the wavelength of the light wave propagating through the optical fiber becomes faster, and a shorter wavelength of the light wave causes the propagation speed of the light as much as possible. Is known to have a so-called positive dispersion characteristic (wavelength dispersion). Then, in general, when light of a semiconductor laser having a certain degree of spread with respect to the center wavelength is incident on an optical fiber having such a dispersion characteristic, the light propagates through the optical fiber as compared with the pulse width of the incident light. The pulse width of the subsequently emitted light becomes wider.
【０００４】このため、前記出射光を光受信側で受信し
たときに、その出射光の独立したパルスを識別できるよ
うにするためには、光ファイバに入射させる入射光のパ
ルス間隔を充分に広く取る必要が生じ、そのように入射
光のパルス間隔を広くすると、高速通信を行うことが困
難となり、そのままでは、半導体レーザと光ファイバを
用いた高速、大容量の通信システムの構築が妨げられて
しまうことになる。Therefore, in order to be able to identify the independent pulses of the emitted light when the emitted light is received at the light receiving side, the pulse interval of the incident light incident on the optical fiber is sufficiently wide. Therefore, if the pulse interval of the incident light is widened, it becomes difficult to perform high-speed communication, and as it is, the construction of a high-speed, large-capacity communication system using a semiconductor laser and an optical fiber is hindered. Will end up.
【０００５】そこで、例えば、図５に示すように、半導
体レーザ１と伝搬用の伝搬用光ファイバ５との間に分散
補償器４を介設し、この分散補償器４により、伝搬用光
ファイバ５の分散特性を補償（分散補償）して伝送光路
全体の分散値をほぼ零とする通信方式（通信システム）
が提案されている。Therefore, for example, as shown in FIG. 5, a dispersion compensator 4 is provided between a semiconductor laser 1 and a propagation optical fiber 5 for propagation. Communication system (communications system) that compensates the dispersion characteristics of 5 (dispersion compensation) and makes the dispersion value of the entire transmission optical path almost zero.
Is proposed.
【０００６】分散補償器４は、光ファイバの光を伝搬す
る部分であるコアの屈折率分布を特殊な分布構造とした
光ファイバの構造分散により、光波の伝搬速度を、波長
が長いほど遅く、短いほど速くした、いわゆる負の分散
特性を有する分散補償光ファイバ３を、例えば、コイル
状に複数回巻き廻して形成した分散補償光ファイバコイ
ル６を有して構成されており、分散補償光ファイバ３の
負の分散値は、伝搬用光ファイバ５の正の分散値と等価
となっている。また、上記のように、分散補償光ファイ
バ３をコイル状に巻くことにより、分散補償光ファイバ
３の占有スペースをできるだけ小さくし、小型の分散補
償器４となるようにしている。In the dispersion compensator 4, due to the structural dispersion of the optical fiber in which the refractive index distribution of the core, which is the portion of the optical fiber that propagates light, has a special distribution structure, the propagation speed of the light wave becomes slower as the wavelength becomes longer, The dispersion compensating optical fiber 3 having a so-called negative dispersion characteristic that is made faster as the length is shorter is constituted by, for example, a dispersion compensating optical fiber coil 6 formed by winding a plurality of times in a coil shape. The negative dispersion value of 3 is equivalent to the positive dispersion value of the propagation optical fiber 5. Further, as described above, by winding the dispersion compensating optical fiber 3 in a coil shape, the space occupied by the dispersion compensating optical fiber 3 is made as small as possible, and the small dispersion compensator 4 is provided.
【０００７】図５に示したような通信システムによれ
ば、分散補償器４により伝搬用光ファイバ５の分散特性
が補償されるために、前記のように、伝搬用光ファイバ
５から出射される出射光のパルス幅が広くなることを防
止できる。According to the communication system as shown in FIG. 5, the dispersion compensator 4 compensates the dispersion characteristic of the propagation optical fiber 5, so that the light is emitted from the propagation optical fiber 5 as described above. It is possible to prevent the pulse width of the emitted light from increasing.
【０００８】[0008]
【発明が解決しようとする課題】しかしながら、上記分
散補償器４は、図３に示すように、分散補償光ファイバ
３を小径のコイル状に巻いて形成した分散補償光ファイ
バコイル６を有しており、このように、長尺の分散補償
光ファイバ３を小径のコイル状に巻いた場合、光ファイ
バ３に曲げによる応力歪が印可され、それによって分散
補償光ファイバ３の軸対称の屈折率の断面構造が崩れ、
例えば、図４に示すように、ファイバ断面（横断面）の
互いに直角をなすＸ軸とＹ軸の屈折率分布が異なるよう
に変化する複屈折という現象が生じる。このコイル巻き
による複屈折は、主にコイル巻きによる曲げにより発生
し、曲げ方向に鉛直な軸の屈折率が変化して生じる。こ
の複屈折は、部分的には僅かなものであるが、長尺の光
ファイバではその複屈折の総量は大きなものとなり、こ
のために、光ファイバを伝搬する光波のうち、Ｘ軸偏波
成分とＹ軸偏波成分との伝搬速度が異なる現象、いわゆ
る偏波分散が生じる。However, as shown in FIG. 3, the dispersion compensator 4 has a dispersion compensating optical fiber coil 6 formed by winding the dispersion compensating optical fiber 3 into a coil having a small diameter. As described above, when the long dispersion-compensating optical fiber 3 is wound into a coil having a small diameter, stress strain due to bending is applied to the optical fiber 3, thereby causing the axially symmetric refractive index of the dispersion-compensating optical fiber 3 to increase. The cross-sectional structure collapses,
For example, as shown in FIG. 4, a phenomenon called birefringence occurs in which the refractive index distributions of the X axis and the Y axis, which are perpendicular to each other in the fiber cross section (transverse cross section), change so as to be different from each other. The birefringence due to the coil winding is mainly caused by the bending due to the coil winding, and is caused by the change in the refractive index of the axis vertical to the bending direction. This birefringence is partly small, but in a long optical fiber, the total amount of the birefringence is large, so that the X-axis polarization component of the light wave propagating in the optical fiber. And a Y-axis polarization component have different propagation velocities, so-called polarization dispersion occurs.
【０００９】そして、このように、分散補償光ファイバ
コイル６に偏波分散が生じると、前記材料分散と同様
に、分散補償光ファイバ３に入射させたレーザ光のパル
ス幅を広げ、高速、大容量の通信システムの構築を妨げ
ることになり、問題であった。When polarization dispersion occurs in the dispersion compensating optical fiber coil 6 in this way, the pulse width of the laser light incident on the dispersion compensating optical fiber 3 is widened in the same manner as the material dispersion, and high speed and high speed are achieved. This is a problem because it hinders the construction of a capacity communication system.
【００１０】本発明は、上記課題を解決するためになさ
れたものであり、その目的は、偏波分散が殆ど生じるこ
とのない分散補償器を提供することにある。The present invention has been made to solve the above problems, and an object thereof is to provide a dispersion compensator in which polarization dispersion hardly occurs.
【００１１】[0011]
【課題を解決するための手段】上記目的を達成するため
に、本発明は次のように構成されている。すなわち、本
発明は、コアの屈折率分布により生じる負の分散特性を
有する分散補償光ファイバを複数回コイル巻きして形成
した分散補償光ファイバコイルを備えた分散補償器にお
いて、前記分散補償光ファイバは捻回された状態でコイ
ル巻きされていることを特徴として構成されている。In order to achieve the above object, the present invention is constructed as follows. That is, the present invention relates to a dispersion compensator including a dispersion compensating optical fiber coil formed by winding a plurality of dispersion compensating optical fibers having a negative dispersion characteristic caused by a refractive index distribution of a core in the dispersion compensating optical fiber. Is characterized by being coiled in a twisted state.
【００１２】また、前記分散補償光ファイバは同一方向
の規則的な周期の捻回が施されていること、前記分散補
償光ファイバは同一方向の不規則な周期の捻回が施され
ていること、前記分散補償光ファイバは捻回方向が交互
で規則的な周期の捻回が施されていること、前記分散補
償光ファイバは捻回方向が交互で不規則な周期の捻回が
施されていることも本発明の特徴的な構成とされてい
る。Further, the dispersion compensating optical fiber is twisted at regular intervals in the same direction, and the dispersion compensating optical fiber is twisted at irregular intervals in the same direction. The dispersion compensating optical fiber is twisted in alternating twisting directions and in a regular cycle, and the dispersion compensating optical fiber is twisted in alternating twisting directions and in an irregular cycle. That is also a characteristic configuration of the present invention.
【００１３】[0013]
【作用】上記構成の本発明において、分散補償光ファイ
バは捻回された状態でコイル巻きされているために、分
散補償光ファイバをコイル巻きするときに、その分散補
償光ファイバに曲げ応力が加わって光ファイバ断面に互
いに直角を成して生じる偏波成分軸の方向およびその偏
波成分の大きさが捻回によって分散され、分散補償光フ
ァイバの長手方向に均一に分布することとなり、それに
より、分散補償器の偏波分散はほぼ零になる。In the present invention having the above structure, since the dispersion compensating optical fiber is coiled in a twisted state, bending stress is applied to the dispersion compensating optical fiber when the dispersion compensating optical fiber is coiled. The direction of the polarization component axis and the magnitude of the polarization component generated at right angles to each other in the optical fiber cross section are dispersed by the twisting, and are evenly distributed in the longitudinal direction of the dispersion compensating optical fiber. , The polarization compensator has almost zero polarization dispersion.
【００１４】[0014]
【実施例】以下、本発明の実施例を図面に基づいて説明
する。なお、本実施例の説明において、従来例と同一名
称部分には同一符号を付しその詳細説明は省略する。図
１には、本発明に係わる分散補償器の一実施例の要部構
成が示されている。本実施例が従来例と異なる特徴的な
ことは、分散補償光ファイバ３が捻回された状態でコイ
ル巻きされて分散補償光ファイバコイル６が形成されて
いることである。Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same names as those in the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted. FIG. 1 shows the configuration of essential parts of an embodiment of a dispersion compensator according to the present invention. This embodiment is different from the conventional example in that the dispersion compensating optical fiber 3 is coiled in a twisted state to form the dispersion compensating optical fiber coil 6.
【００１５】なお、分散補償光ファイバ３は、ゲルマニ
ュームをドープしたコアの屈折率分布を特殊な分布構造
とし、その構造分散により−80psec／nm／kmの負の分散
特性を有するように構成した長さ15kmの光ファイバであ
り、この分散補償光ファイバ３を、胴径60mmφ、胴幅42
mmのアルミ製ボビンに、１回／900 mmの同一方向の規則
的な周期の捻回を施してコイル巻きして分散補償光ファ
イバコイル６が形成されている。The dispersion compensating optical fiber 3 has a long refractive index distribution of the germanium-doped core and has a special distribution structure, and has a negative dispersion characteristic of -80 psec / nm / km due to the structural dispersion. This dispersion-compensating optical fiber 3 has a diameter of 60 mm and a width of 42 mm.
A dispersion compensating optical fiber coil 6 is formed by winding a coil made of an aluminum bobbin of mm once / 900 mm at regular intervals in the same direction and winding the coil.
【００１６】本実施例は以上のように構成されており、
本実施例でも、分散補償光ファイバ３をコイル巻きする
ときに、その分散補償光ファイバ３に曲げ応力が加わっ
て複屈折が生じるが、本実施例では、分散補償光ファイ
バ３を捻回した状態でコイル巻きしているために、例え
ば、分散補償光ファイバ３を図１の線Ａ〜Ｋで切断した
ときのファイバ横断面の屈折率分布は、図２のＡ〜Ｋに
示すようになり、前記複屈折により生じる偏波成分軸の
方向（図のＸ方向、Ｙ方向）およびその偏波成分の大き
さが捻回によって分散される。そして、このことによ
り、偏波成分軸の方向およびその偏波成分の大きさが分
散補償光ファイバ３の長手方向に均一に分布することと
なり、それにより、分散補償光ファイバコイル６の偏波
分散がほぼ零になり、分散補償器４の偏波分散はほぼ零
となる。The present embodiment is configured as described above,
Also in this embodiment, when the dispersion compensating optical fiber 3 is wound by a coil, bending stress is applied to the dispersion compensating optical fiber 3 to cause birefringence, but in the present embodiment, the dispersion compensating optical fiber 3 is twisted. Since the coil is wound at, the refractive index distribution of the cross section of the fiber when the dispersion compensating optical fiber 3 is cut along the lines A to K in FIG. 1 is as shown in A to K in FIG. The directions of the polarization component axes (X direction and Y direction in the drawing) and the magnitudes of the polarization components generated by the birefringence are dispersed by twisting. As a result, the direction of the polarization component axis and the magnitude of the polarization component are evenly distributed in the longitudinal direction of the dispersion compensating optical fiber 3, which causes the polarization dispersion of the dispersion compensating optical fiber coil 6. Becomes almost zero, and the polarization dispersion of the dispersion compensator 4 becomes almost zero.
【００１７】実際に、本実施例の分散補償器４の分散補
償光ファイバコイル６の偏波特性をジョーンズマトリク
ス法で測定した結果、偏波分散値は0.13psecであり、コ
イル巻きする前の分散補償光ファイバ３の偏波分散値
（0.12psec）とほぼ等しい値となり、偏波分散値の増加
は殆どないことが確認された。なお、本実施例の分散補
償器４の波長分散は−1198psec／nmであり、従来の分散
補償器４と同等の補償効果を有していることが確認され
た。本実施例によれば、上記のように、偏波分散が殆ど
生じることのない分散補償器４を形成することが可能と
なるために、例えば、図５に示したように、半導体レー
ザ１等の光をパルス信号で変調し、伝搬用光ファイバ５
に伝送させる通信システムに本実施例の分散補償器４を
介設すれば、従来の分散補償器４のように、レーザ光の
パルス幅を分散補償器４の偏波分散により広げることは
なく、伝搬用光ファイバ５の材料分散を補償して材料分
散によるパルス幅の広がりを防ぐことが可能となり、高
速、大容量の通信システムの構築が可能となる。Actually, as a result of measuring the polarization characteristic of the dispersion compensating optical fiber coil 6 of the dispersion compensator 4 of this embodiment by the Jones matrix method, the polarization dispersion value is 0.13 psec, which is before the coil winding. It was confirmed that the value was almost equal to the polarization dispersion value (0.12 psec) of the dispersion compensating optical fiber 3, and that there was almost no increase in the polarization dispersion value. The chromatic dispersion of the dispersion compensator 4 of the present embodiment was −1198 psec / nm, and it was confirmed that the dispersion compensator 4 had a compensation effect equivalent to that of the conventional dispersion compensator 4. According to the present embodiment, as described above, it is possible to form the dispersion compensator 4 in which the polarization dispersion hardly occurs. Therefore, for example, as shown in FIG. Light is modulated with a pulse signal and propagated through an optical fiber 5
If the dispersion compensator 4 of the present embodiment is provided in the communication system for transmitting the signal, the pulse width of the laser light is not widened by the polarization dispersion of the dispersion compensator 4, unlike the conventional dispersion compensator 4. The dispersion of the pulse width due to the material dispersion can be prevented by compensating for the material dispersion of the propagation optical fiber 5, and a high speed and large capacity communication system can be constructed.
【００１８】なお、本発明は上記実施例に限定されるこ
とはなく様々な実施の対応を採り得る。例えば、上記実
施例では、分散補償光ファイバコイル６は、長さ15kmの
分散補償光ファイバ３を１回／900 ｍの同一方向の規則
的な周期を施してコイル巻きして形成したが、分散補償
光ファイバ３の捻回の回数等は特に限定されることはな
い。また、分散補償光ファイバコイル６は、上記実施例
のように、必ずしも同一方向の規則的な周期の捻回が施
された分散補償光ファイバ３により形成されるとは限ら
ず、分散補償光ファイバコイル６は、例えば、同一方向
の不規則な周期の捻回が施された分散補償光ファイバ３
により形成されていても構わない。The present invention is not limited to the above-mentioned embodiment, and various measures can be taken. For example, in the above embodiment, the dispersion compensating optical fiber coil 6 is formed by winding the dispersion compensating optical fiber 3 having a length of 15 km at a regular cycle of once per 900 m in the same direction. The number of times the compensating optical fiber 3 is twisted is not particularly limited. Further, the dispersion compensating optical fiber coil 6 is not necessarily formed by the dispersion compensating optical fiber 3 which is twisted in the same direction at a regular cycle as in the above embodiment, and the dispersion compensating optical fiber is not necessarily formed. The coil 6 is, for example, a dispersion-compensating optical fiber 3 that is twisted in an irregular direction in the same direction.
It may be formed by.
【００１９】実際に、上記実施例と同様の分散補償光フ
ァイバ３に、同一の捻回方向で、捻回率を５〜20回／10
ｍとしてランダムに変化させて不規則な周期の捻回を施
し、上記実施例と同様のボビンにコイル巻きして分散補
償光ファイバコイル６を形成し、その分散補償光ファイ
バコイル６の偏波特性をジョーンズマトリクス法で測定
した結果、偏波分散値は0.13psecであり、上記実施例と
同様の値であることが確認されている。また、このコイ
ルの波長分散は−1198psec／nmであり、上記実施例と同
様の値となり、同等の補償効果を有することも確認され
ている。Actually, in the same dispersion compensating optical fiber 3 as in the above embodiment, the twist rate is 5 to 20 times / 10 in the same twist direction.
As m, the dispersion compensation optical fiber coil 6 is formed by winding the bobbin in the same manner as in the above embodiment by twisting the dispersion compensation optical fiber coil 6 at irregular intervals and twisting the polarization compensation characteristic of the dispersion compensation optical fiber coil 6. As a result of measuring the property by the Jones matrix method, it is confirmed that the polarization dispersion value is 0.13 psec, which is the same value as that in the above-mentioned embodiment. It was also confirmed that the wavelength dispersion of this coil was -1198 psec / nm, which was the same value as in the above-mentioned example, and had the same compensation effect.
【００２０】また、分散補償光ファイバコイル６は、捻
回方向が交互で規則的な周期の捻回が施された分散補償
光ファイバ３がコイル巻きされて形成されていても構わ
ない。例えば、上記実施例に用いた分散補償光ファイバ
３と同様の分散補償光ファイバ３に、１回／900 mmの捻
回率で最初の1800mmに同一方向の捻回を施し、次の1800
mmは捻回を加えず、さらに次の1800mmは１回／900 mmの
捻回率で最初の1800mmとは反対方向の捻回を加えて上記
実施例と同様のボビンにコイル巻きし、以後、順次これ
と同一の捻回を繰り返し加えて15kmの分散補償光ファイ
バ３の全長をコイル巻きして分散補償光ファイバコイル
６を形成し、その偏波特性をジョーンズマトリクス法で
測定した結果、偏波分散値は0.13psecであった。また、
その分散補償光ファイバコイル６の波長分散は−1198ps
ec／nmであり、偏波分散および波長分散ともに上記実施
例と同様の値であることが確認された。Further, the dispersion compensating optical fiber coil 6 may be formed by winding the dispersion compensating optical fiber 3 in which the twisting directions are alternated and which is twisted in a regular cycle. For example, a dispersion-compensating optical fiber 3 similar to the dispersion-compensating optical fiber 3 used in the above embodiment is twisted in the same direction for the first 1800 mm at a twist rate of once / 900 mm, and then the next 1800 mm.
mm was not twisted, and the next 1800 mm was twisted in a direction opposite to the first 1800 mm at a twist rate of 1 turn / 900 mm, and the coil was wound on a bobbin similar to that in the above-mentioned embodiment. The same twisting was repeated in sequence to form a dispersion compensating optical fiber coil 6 by winding the entire length of the dispersion compensating optical fiber 3 of 15 km, and the polarization characteristics were measured by the Jones matrix method. The wave dispersion value was 0.13 psec. Also,
The wavelength dispersion of the dispersion compensating optical fiber coil 6 is -1198 ps.
It was ec / nm, and it was confirmed that the polarization dispersion and the wavelength dispersion were the same values as in the above-mentioned examples.
【００２１】さらに、分解補償光ファイバコイル６は、
捻回方向が交互で不規則な周期の捻回が施された分散補
償光ファイバ３により形成されていても構わない。例え
ば、上記実施例と同様の分散補償光ファイバ３に、同一
の捻回方向で捻回率が５〜20回／10ｍの範囲でランダム
に変化させた捻回を最初の1800mmに施し、次の1800mmに
は、最初の1800mmとは反対方向の捻回方向で捻回率を５
〜20回／10ｍの範囲でランダムに変化させた捻回を施し
て、上記実施例と同様のボビンにコイル巻きして分散補
償光ファイバコイル６を形成したところ、その偏波分散
値は0.13psecであり、過剰分散は−1198psec／nmであ
り、いずれも上記実施例と同様の値であり、同様の効果
を奏することが確認された。Further, the decomposition compensation optical fiber coil 6 is
It may be formed by the dispersion compensating optical fiber 3 in which the twisting directions are alternated and twisted in an irregular cycle. For example, the same dispersion-compensating optical fiber 3 as in the above embodiment is subjected to a twisting in which the twisting rate is randomly changed within the range of 5 to 20 turns / 10 m in the same twisting direction, and is applied to the first 1800 mm. For 1800 mm, the twist rate is 5 in the twist direction opposite to the first 1800 mm.
The dispersion compensating optical fiber coil 6 was formed by winding the bobbin in the same manner as in the above-mentioned embodiment by twisting it at random within a range of up to 20 turns / 10 m, and its polarization dispersion value was 0.13 psec. It was confirmed that the excessive dispersion was −1198 psec / nm, which was the same value as in the above-mentioned examples, and the same effect was obtained.
【００２２】さらに、上記実施例では、分散補償光ファ
イバ３は、−80psec／nm／kmの分散特性を有する、長さ
15kmの分散補償光ファイバとし、この分散補償光ファイ
バ３を胴径60mmφ、胴幅42mmのアルミ製ボビンにコイル
巻きして分散補償光ファイバコイル６を形成したが、分
散補償光ファイバコイル６を形成する分散補償光ファイ
バ３の分散特性や長さ等は特に限定されるものではな
く、例えば、図５のような通信システムにおける伝搬用
光ファイバ５の分散特性を補償できるように適宜設定さ
れるものである。Furthermore, in the above embodiment, the dispersion compensating optical fiber 3 has a dispersion characteristic of -80 psec / nm / km and a length of
A dispersion compensating optical fiber 6 is formed by forming a dispersion compensating optical fiber of 15 km and winding the dispersion compensating optical fiber 3 around an aluminum bobbin having a body diameter of 60 mmφ and a body width of 42 mm. The dispersion characteristics, length, etc. of the dispersion compensating optical fiber 3 are not particularly limited, and are set appropriately so as to be able to compensate for the dispersion characteristics of the propagation optical fiber 5 in the communication system as shown in FIG. 5, for example. Is.
【００２３】[0023]
【発明の効果】本発明によれば、分散補償光ファイバを
捻回した状態でコイル巻きして分散補償光ファイバコイ
ルを形成するために、このコイル巻きのときに分散補償
光ファイバに曲げ応力が加わって生じる偏波成分軸の方
向およびその偏波成分の大きさを捻回によって分散さ
せ、偏波成分軸の方向および偏波成分の大きさを分散補
償光ファイバの長手方向に均一に分布することが可能と
なり、それにより、分散補償光ファイバコイルの偏波分
散をほぼ零とすることができる。According to the present invention, in order to form a dispersion compensating optical fiber coil by winding the dispersion compensating optical fiber in a twisted state, a bending stress is applied to the dispersion compensating optical fiber during the coil winding. The direction of the added polarization component axis and the magnitude of the polarization component are dispersed by twisting, and the direction of the polarization component axis and the magnitude of the polarization component are evenly distributed in the longitudinal direction of the dispersion compensating optical fiber. Therefore, the polarization dispersion of the dispersion compensating optical fiber coil can be made almost zero.
【００２４】そのため、本発明によれば、偏波分散が殆
ど生じることのない分散補償器を形成することが可能と
なり、例えば、半導体レーザ等の光をパルス信号で変調
し、伝搬用の光ファイバに伝送させる通信システムに本
発明の分散補償器を介設すれば、従来の分散補償器のよ
うに、ある程度の波長の広がりを有するレーザ光のパル
ス幅を分散補償器の偏波分散により広げることはなく、
伝搬用の光ファイバの材料分散を補償して材料分散によ
るパルス幅の広がりを防ぐことができるために、高速、
大容量の通信システムの構築が可能となる。Therefore, according to the present invention, it is possible to form a dispersion compensator in which polarization dispersion hardly occurs. For example, a semiconductor laser or the like is modulated with a pulse signal, and an optical fiber for propagation is used. If the dispersion compensator according to the present invention is provided in a communication system for transmitting in the same way, the pulse width of the laser light having a certain wavelength spread can be widened by the polarization dispersion of the dispersion compensator as in the conventional dispersion compensator. Not,
High-speed, because it is possible to compensate the material dispersion of the optical fiber for propagation and prevent the spread of the pulse width due to the material dispersion.
It is possible to construct a large capacity communication system.
【図１】本発明に係わる分散補償器の一実施例を示す要
部構成図である。FIG. 1 is a main part configuration diagram showing an embodiment of a dispersion compensator according to the present invention.
【図２】図１の線Ａ〜Ｋで分散補償光ファイバを切断し
たときの各ファイバ横断面の屈折率分布を示す説明図で
ある。FIG. 2 is an explanatory diagram showing a refractive index distribution of each fiber cross section when the dispersion compensating optical fiber is cut along lines A to K in FIG.
【図３】従来の分散補償器の分散補償光ファイバコイル
を示す説明図である。FIG. 3 is an explanatory diagram showing a dispersion compensating optical fiber coil of a conventional dispersion compensator.
【図４】図３の分散補償光ファイバコイルのＡ−Ａ′断
面の屈折率分布を示す説明図である。FIG. 4 is an explanatory diagram showing a refractive index distribution in the AA ′ cross section of the dispersion compensating optical fiber coil of FIG. 3.
【図５】分散補償器を用いた通信システムの一例を示す
説明図である。FIG. 5 is an explanatory diagram showing an example of a communication system using a dispersion compensator.
３ 分散補償光ファイバ ４ 分散補償器 ６ 分散補償光ファイバコイル 10 コア 3 dispersion compensating optical fiber 4 dispersion compensator 6 dispersion compensating optical fiber coil 10 cores
Claims (5)
特性を有する分散補償光ファイバを複数回コイル巻きし
て形成した分散補償光ファイバコイルを備えた分散補償
器において、前記分散補償光ファイバは捻回された状態
でコイル巻きされていることを特徴とする分散補償器。1. A dispersion compensator comprising a dispersion compensating optical fiber coil formed by winding a plurality of times a dispersion compensating optical fiber having a negative dispersion characteristic caused by a refractive index distribution of a core, wherein the dispersion compensating optical fiber is A dispersion compensator characterized by being coiled in a twisted state.
な周期の捻回が施されていることを特徴とする請求項１
記載の分散補償器。2. The dispersion compensating optical fiber is twisted at regular intervals in the same direction.
The dispersion compensator described.
な周期の捻回が施されていることを特徴とする請求項１
記載の分散補償器。3. The dispersion compensating optical fiber is twisted in an irregular cycle in the same direction.
The dispersion compensator described.
規則的な周期の捻回が施されていることを特徴とする請
求項１記載の分散補償器。4. The dispersion compensator according to claim 1, wherein the dispersion compensating optical fiber is twisted in a regular cycle with alternating twisting directions.
不規則な周期の捻回が施されていることを特徴とする請
求項１記載の分散補償器。5. The dispersion compensator according to claim 1, wherein the dispersion compensating optical fiber is twisted in an irregular cycle with alternating twisting directions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6205948A JPH0850208A (en) | 1994-08-08 | 1994-08-08 | Dispersion compensator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6205948A JPH0850208A (en) | 1994-08-08 | 1994-08-08 | Dispersion compensator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0850208A true JPH0850208A (en) | 1996-02-20 |
Family
ID=16515368
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6205948A Pending JPH0850208A (en) | 1994-08-08 | 1994-08-08 | Dispersion compensator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0850208A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000014579A1 (en) * | 1998-09-09 | 2000-03-16 | Deutsche Telekom Ag | Optical junction section |
| WO2000041011A1 (en) * | 1999-01-06 | 2000-07-13 | Sumitomo Electric Industries, Ltd. | Dispersion compensating optical fiber |
| WO2000060775A1 (en) * | 1999-04-01 | 2000-10-12 | Sumitomo Electric Industries, Ltd. | Wdm optical communication system |
| JP2001021740A (en) * | 1999-07-05 | 2001-01-26 | Nippon Telegr & Teleph Corp <Ntt> | Wavelength dispersion compensating device, and manufacture thereof |
| JP2002541509A (en) * | 1999-03-31 | 2002-12-03 | ピレリー・カビ・エ・システミ・ソチエタ・ペル・アツィオーニ | Optical cable for telecommunications |
| US6546180B1 (en) | 1999-01-06 | 2003-04-08 | Sumitomo Electric Industries, Ltd. | Coiled optical assembly and fabricating method for the same |
| US6650821B1 (en) | 1999-01-06 | 2003-11-18 | Sumitomo Electric Industries, Ltd. | Optical device and a making method thereof |
| EP1366378A2 (en) * | 2001-01-31 | 2003-12-03 | OmniGuide, Inc. | Electromagnetic mode conversion in photonic crystal multimode waveguides |
| WO2009107667A1 (en) * | 2008-02-28 | 2009-09-03 | 住友電気工業株式会社 | Optical fiber |
| WO2009147881A1 (en) * | 2008-06-05 | 2009-12-10 | 住友電気工業株式会社 | Equipment for manufacturing coated optical fiber and method for manufacturing coated optical fiber |
-
1994
- 1994-08-08 JP JP6205948A patent/JPH0850208A/en active Pending
Cited By (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002524764A (en) * | 1998-09-09 | 2002-08-06 | ドイッチェ テレコム アーゲー | Optical communication link |
| WO2000014579A1 (en) * | 1998-09-09 | 2000-03-16 | Deutsche Telekom Ag | Optical junction section |
| US6813424B1 (en) | 1998-09-09 | 2004-11-02 | Deutsche Telekom Ag Bonn | Optical communications link |
| US7043131B2 (en) | 1999-01-06 | 2006-05-09 | Sumitomo Electric Industries, Ltd. | Optical device and a making method thereof |
| WO2000041011A1 (en) * | 1999-01-06 | 2000-07-13 | Sumitomo Electric Industries, Ltd. | Dispersion compensating optical fiber |
| US6546180B1 (en) | 1999-01-06 | 2003-04-08 | Sumitomo Electric Industries, Ltd. | Coiled optical assembly and fabricating method for the same |
| US6650821B1 (en) | 1999-01-06 | 2003-11-18 | Sumitomo Electric Industries, Ltd. | Optical device and a making method thereof |
| JP2002541509A (en) * | 1999-03-31 | 2002-12-03 | ピレリー・カビ・エ・システミ・ソチエタ・ペル・アツィオーニ | Optical cable for telecommunications |
| WO2000060775A1 (en) * | 1999-04-01 | 2000-10-12 | Sumitomo Electric Industries, Ltd. | Wdm optical communication system |
| US6687433B2 (en) | 1999-04-01 | 2004-02-03 | Sumitomo Electric Industries, Ltd. | WDM optical communication system |
| JP2001021740A (en) * | 1999-07-05 | 2001-01-26 | Nippon Telegr & Teleph Corp <Ntt> | Wavelength dispersion compensating device, and manufacture thereof |
| EP1366378A4 (en) * | 2001-01-31 | 2005-11-09 | Omniguide Comm Inc | Electromagnetic mode conversion in photonic crystal multimode waveguides |
| EP1366378A2 (en) * | 2001-01-31 | 2003-12-03 | OmniGuide, Inc. | Electromagnetic mode conversion in photonic crystal multimode waveguides |
| WO2009107667A1 (en) * | 2008-02-28 | 2009-09-03 | 住友電気工業株式会社 | Optical fiber |
| JP5229313B2 (en) * | 2008-02-28 | 2013-07-03 | 住友電気工業株式会社 | Optical fiber |
| US8483531B2 (en) | 2008-02-28 | 2013-07-09 | Sumitomo Electric Industries, Ltd. | Optical fiber |
| WO2009147881A1 (en) * | 2008-06-05 | 2009-12-10 | 住友電気工業株式会社 | Equipment for manufacturing coated optical fiber and method for manufacturing coated optical fiber |
| JP5229319B2 (en) * | 2008-06-05 | 2013-07-03 | 住友電気工業株式会社 | Coated optical fiber manufacturing apparatus and coated optical fiber manufacturing method |
| US8756906B2 (en) | 2008-06-05 | 2014-06-24 | Sumitomo Electric Industries, Ltd. | Coated optical fiber producing apparatus and coated optical fiber producing method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5721800A (en) | Dispersion-shifted fiber | |
| JP4101429B2 (en) | Multimode optical fiber with higher-order mode rejection | |
| EP1116968B1 (en) | Multimode optical fiber with high-order mode removing function | |
| Grüner-Nielsen et al. | Dispersion compensating fibers | |
| JP4612583B2 (en) | Optical fiber filter for suppression of amplified spontaneous emission | |
| EP0674193B1 (en) | Dispersion compensating optical fiber and optical transmission system including such fiber | |
| US9588284B2 (en) | Multi-core fiber | |
| Hayashi et al. | Low-crosstalk and low-loss multi-core fiber utilizing fiber bend | |
| JP4999063B2 (en) | Optical fiber | |
| JPS59148005A (en) | Optical fiber for propagating single mode single polarized wave | |
| US6466721B1 (en) | Dispersion compensating optical fiber and optical transmission line | |
| US7505667B2 (en) | Waveguide configuration | |
| KR20020095111A (en) | Method of winding optical fiber on reel | |
| JPH0850208A (en) | Dispersion compensator | |
| US7463807B2 (en) | Waveguide configuration | |
| JP2001318260A (en) | Polarized wave maintaining optical fiber | |
| WO2003098296A1 (en) | Dispersion shift optical fiber | |
| US20180088360A1 (en) | Polarization Maintaining Optical Fiber With Non-Symmetric Stress Applying Parts | |
| JPH10115727A (en) | Dispersion compensating optical fiber | |
| US6628873B1 (en) | Dispersion shifted fiber for wavelength division multiplex fiber optic transmission systems | |
| JP2001159721A (en) | Dispersion compensating optical fiber | |
| JP2931208B2 (en) | Dispersion compensator | |
| JP4104846B2 (en) | Optical fiber | |
| US7194171B2 (en) | Dispersion compensating optical fiber, dispersion compensating device, optical transmission line and optical transmission system | |
| JPH0926518A (en) | Dispersion compensation optical fiber module |