JPS617436A - Method for measuring connection loss of optical fiber - Google Patents
Method for measuring connection loss of optical fiberInfo
- Publication number
- JPS617436A JPS617436A JP12640084A JP12640084A JPS617436A JP S617436 A JPS617436 A JP S617436A JP 12640084 A JP12640084 A JP 12640084A JP 12640084 A JP12640084 A JP 12640084A JP S617436 A JPS617436 A JP S617436A
- Authority
- JP
- Japan
- Prior art keywords
- light
- optical fiber
- connection
- loss
- optical fibers
- 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
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
- G01M11/30—Testing of optical devices, constituted by fibre optics or optical waveguides
- G01M11/35—Testing of optical devices, constituted by fibre optics or optical waveguides in which light is transversely coupled into or out of the fibre or waveguide, e.g. using integrating spheres
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Optical Devices Or Fibers (AREA)
- Light Guides In General And Applications Therefor (AREA)
Abstract
Description
【発明の詳細な説明】
(発明の技術分野)
本発明は光ファイバ接続工程中の接続損失測定を接続点
だけで行う方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a method for measuring splice loss during an optical fiber splicing process only at splicing points.
(従来の技術)
従来は第1図に示すように1接続する2本の光ファイバ
1−1.1−2のうち一方1−1の接続点から離れた端
から光源1−3により光を入射し、接続点で受光器1−
4により受光レベルを測定した後〔第1図(a)〕、光
ファイバ1−1 、1−2間を仮接続点1−5で仮接続
し、もう一方の光ファイバ1−2の接続点1−5から離
れた端で受光器1−4により受光レベルを測定し〔第1
図(b)〕、接続点1−5から光進行方向に1m程度離
れた位置を切断し、その位置で受光器1−4により受光
レベルを測定することにより〔第1図(c)〕、後方の
光ファイバの伝送損失を計測したのち再び光ファイバ1
−1.1−2間を接続し、後方の光ファイバ1−2の端
での受光レベルを受光器1−4により測定することによ
り〔第1図(d)〕、接続損失を測定していた。このた
め、接続点以外に接続する光ファイバの両端に光源と受
光器が必要であシ、現場作業においては遠く離れたこれ
ら3箇所に作業者が分散し、作業効率が悪いほか互いに
密な連絡をとりながら測定を行なうという複雑なもので
あった。また、作業場所が3箇所に別れるため、作業者
と測定器具を多く必要としコストが高くなるという欠点
があった。さらに、通常光源は電話局等の場所に固定す
ることが多いので、直列に多数本の光ファイバを接続す
る際には、光源から近い順に順番に接続しなければなら
ず、作業効率が非常に悪いという欠点があった。(Prior art) Conventionally, as shown in Fig. 1, a light source 1-3 emits light from the end of one of the two optical fibers 1-1, 1-2 connected together, which is remote from the connection point of one 1-1. The light enters the receiver 1- at the connection point.
After measuring the received light level by step 4 [Fig. 1(a)], temporarily connect optical fibers 1-1 and 1-2 at temporary connection point 1-5, and connect the other optical fiber 1-2 to the connection point. The received light level is measured by the light receiver 1-4 at the end far from the first
(b)], by cutting at a position approximately 1 m away from the connection point 1-5 in the direction of light propagation, and measuring the received light level with the light receiver 1-4 at that position [Fig. 1 (c)]. After measuring the transmission loss of the rear optical fiber, connect optical fiber 1 again.
-1.1-2, and measure the light reception level at the end of the rear optical fiber 1-2 with the receiver 1-4 [Fig. 1(d)] to measure the splice loss. Ta. For this reason, a light source and a receiver are required at both ends of the optical fiber to be connected in addition to the connection point, and during field work, workers are dispersed to these three far apart locations, resulting in poor work efficiency and poor communication between each other. It was a complicated process, requiring measurements to be taken while taking measurements. Furthermore, since the work place is divided into three locations, there is a drawback that many workers and measuring instruments are required, which increases the cost. Furthermore, since light sources are usually fixed at locations such as telephone offices, when connecting multiple optical fibers in series, they must be connected in order from the light source, which greatly reduces work efficiency. There was a downside to it being bad.
(発明の目的)
本発明は、これらの欠点を解決するだめ、接続点に光を
照射して光ファイバ中に光を注入し接続点の近くで光フ
ァイバ中を伝播してきた光を曲げ放射させその光を受光
することにより、接続点のみで接続損失を高精度にかつ
簡便に測定することのできる光ファイバ接続損失測定方
法を提供するものである。(Objective of the Invention) In order to solve these drawbacks, the present invention irradiates the connection point with light, injects the light into the optical fiber, and bends and radiates the light that has propagated through the optical fiber near the connection point. An object of the present invention is to provide an optical fiber splice loss measuring method that can easily and highly accurately measure splice loss only at splicing points by receiving the light.
(発明の原理)
以下本発明の詳細な説明する8
本発明の基本的な原理は、光ファイバ接続点における光
ファイバの構造上の変形に起因する光の散乱を利用する
ことにある。第2図は光ファイバ2−1の接続部の拡大
断面概念図である。接続点2−5においてコア2−2の
軸ずれや変形等が発生すると、コア2−2中を伝播する
光2−3は接続点2−5で散乱を受け、一部が漏洩光2
−4としてコア2−2の外へ漏洩する。この漏洩光2−
4は、この接続点2−5における接続損失である。卓ら
に、この漏洩光2−4の一部は光ファイバ2−1のクラ
ッド部から外へ漏れ、従って、損失を有する接続点では
、伝播光2−3の一部を損失に対応して光ファイバ2−
2の外で観測することができる。本発明は、この現象の
逆の過程を原理としている。(Principle of the Invention) The present invention will be described in detail below.8 The basic principle of the present invention is to utilize the scattering of light caused by the structural deformation of the optical fiber at the optical fiber connection point. FIG. 2 is an enlarged conceptual cross-sectional view of the connecting portion of the optical fiber 2-1. When an axis shift or deformation of the core 2-2 occurs at the connection point 2-5, the light 2-3 propagating through the core 2-2 is scattered at the connection point 2-5, and a part of it becomes the leakage light 2.
-4 leaks out of the core 2-2. This leaked light 2-
4 is the connection loss at this connection point 2-5. Obviously, a part of this leaked light 2-4 leaks out from the cladding part of the optical fiber 2-1, and therefore, at a connection point having a loss, a part of the propagating light 2-3 is transferred to compensate for the loss. Optical fiber 2-
It can be observed outside of 2. The present invention is based on the reverse process of this phenomenon.
第3図は、光ファイバ2−2の接続部2−5に周囲から
光を照射した状態を示す概念図である。損失を有する接
続点3−5に光コア・イバ3−1の外部から光3−4を
照射すると、ちょうどコア3−2内の伝播光3−3が光
ファイバ3−1の外部へ漏洩する逆の過程をたどって、
外部からの照射光3−4の一部が伝播光3−3としてコ
ア内を伝わることになる。この伝播光3−3の強度は、
外部からの照射光3−4の強度が一定であれば、接続損
失吟対応した値となり、損失が高ければ強く、また低け
れば弱い。このようにして、接続損失に応じた光強度を
持つ伝播光3−3を接続点3−5で発生させることがで
き、この伝播光3−3の強度を接続部3−5の近くで光
ファイバを破壊することなく測定すれば、接続損失を接
続場所だけで測定することができる。伝播光強度の測定
は光ファイバ2−1 、3−1を曲げることにより、曲
げ部から光ファイバの外へ放出される光を受光して行う
。FIG. 3 is a conceptual diagram showing a state in which the connecting portion 2-5 of the optical fiber 2-2 is irradiated with light from the surroundings. When the light 3-4 is irradiated from the outside of the optical core fiber 3-1 to the connection point 3-5 having a loss, the propagating light 3-3 inside the core 3-2 just leaks to the outside of the optical fiber 3-1. Following the reverse process,
A part of the irradiated light 3-4 from the outside is transmitted through the core as propagated light 3-3. The intensity of this propagating light 3-3 is
If the intensity of the irradiated light 3-4 from the outside is constant, the value corresponds to the connection loss, and the higher the loss, the stronger it is, and the lower the loss, the weaker. In this way, the propagating light 3-3 having an optical intensity corresponding to the connection loss can be generated at the connection point 3-5, and the intensity of this propagating light 3-3 can be changed to a light source near the connection part 3-5. By measuring without destroying the fiber, splice loss can be measured only at the splice location. The propagation light intensity is measured by bending the optical fibers 2-1 and 3-1 and receiving the light emitted from the bent portion to the outside of the optical fiber.
(発明の構成及び作用) 次に測定方法について述べる。(Structure and operation of the invention) Next, the measurement method will be described.
第4図は本発明の測定方法を説明するだめの概念図であ
シ、4−1 、4−2は光ファイバ、4−3は接続点、
4−4は受光器、4−5は第−曲げ部、4−6は第二曲
げ部、4−7は第−曲げ部で放出される光、4−8は第
二曲げ部で放出さ庇る光、4−9は照明器、4−10は
接続点に照射される光を表わす。FIG. 4 is a conceptual diagram for explaining the measurement method of the present invention, 4-1 and 4-2 are optical fibers, 4-3 is a connection point,
4-4 is the light receiver, 4-5 is the first bending part, 4-6 is the second bending part, 4-7 is the light emitted at the first bending part, and 4-8 is the light emitted at the second bending part. 4-9 represents the illuminator, and 4-10 represents the light irradiated to the connection point.
接続損失をθ1j定するには、まず、接続前に光ファイ
バ4−1と4−2の端面を十分熱した状態で照明器4−
9により光を光ファイバ4−1 、4−2の端部に照射
し、第二曲げ部4−6で放出される光4−8を受光器4
−4で受光する。十分熱した状態とは、光ファイバつき
合わせ状態における第二曲は部4−6での受光値が第5
図に示すようにほぼ一定となる端面間隔に設定した状態
を意味する。第5図に示す例では、端面間隔が0.5w
ux以上の領域である。この状態における受光値を測定
系の基準値とする。To determine the splice loss θ1j, first heat the end faces of the optical fibers 4-1 and 4-2 sufficiently before connecting the illuminator 4-1.
9 irradiates the end portions of the optical fibers 4-1 and 4-2 with light, and the light 4-8 emitted from the second bending portion 4-6 is transmitted to the receiver 4.
Receives light at -4. The sufficiently heated state means that in the second track when the optical fibers are connected, the light reception value at section 4-6 is the fifth.
As shown in the figure, this refers to a state in which the end face spacing is set to be approximately constant. In the example shown in Figure 5, the end face spacing is 0.5w.
This is an area greater than or equal to ux. The light reception value in this state is used as the reference value of the measurement system.
次に、接続した後に再度照明器4−9により接続部4−
3に光を照射して、第二曲げ部4−6で受光する。この
とき、上記基準値を測定したときと同じ条件で測定する
必要がちシ、第−曲げ部4−5と第二曲げ部4−6は測
定中固定した状態を保ち、照明器4−9.受光器4−4
も固定しておく。前述した原理に従い、接続部4−3に
光を照射すると、光ファイバ4−1.4−2のコア内に
接続損失に対応した光4−10が入射する。ただし、測
定に必要な伝播モード光だけではなく、同時にクラッド
モードの光も光ファイバ4−1.4−2内に発生し、し
かも、クラッドモード光は通常光ファイバ4−1.4−
2内を数十のから数mは伝播する。そのだめ、接続点4
−3の近くで光ファイバ4−1 、4−2内を伝播する
光の強度を測定しても正しく接続損失を測定することは
できない。このクラッドモードを除去り。Next, after the connection, the illuminator 4-9 is used again to connect the connection part 4-
3 is irradiated with light, and the light is received by the second bent portion 4-6. At this time, it is necessary to measure under the same conditions as when measuring the reference value, and the first bent part 4-5 and the second bent part 4-6 are kept fixed during the measurement, and the illuminator 4-9. Receiver 4-4
Also keep it fixed. According to the above-described principle, when light is irradiated onto the connection portion 4-3, light 4-10 corresponding to the connection loss is incident into the core of the optical fiber 4-1.4-2. However, in addition to the propagation mode light necessary for measurement, cladding mode light is also generated within the optical fiber 4-1.4-2.
It propagates within 2 for tens of meters to several meters. No, connection point 4
Even if the intensity of the light propagating within the optical fibers 4-1 and 4-2 is measured near the optical fibers 4-3 and 4-2, it is not possible to accurately measure the splice loss. Remove this cladding mode.
接続損失に対応している伝播モードの光のみを測定する
ために、第−曲げ部4−5が用意される。In order to measure only the light in the propagation mode corresponding to the connection loss, the -th bending section 4-5 is prepared.
第6図には、第−曲げ部4−5における光ファイバ4−
2の曲げ直径と伝播モード光の透過率、および、照明器
4−9(ここではクセノン放電管を使用)で光ファイバ
中に発生させたクラッドモード光の透過率の測定値を示
しである。光ファイバ4−2の曲げは、半円状に一回曲
げたものでおる。本図かられかるように、曲は直径を5
Mにすると、クラッドモード光の透過率は伝播モード光
の1/14となる。伝播モード光強度も約1/3に減少
するが、クラッドモード光は約1/40に減少し、はぼ
完全に除去することができる。FIG. 6 shows the optical fiber 4-5 at the bending portion 4-5.
2 shows the measured values of the bending diameter of No. 2, the transmittance of the propagation mode light, and the transmittance of the cladding mode light generated in the optical fiber by the illuminator 4-9 (here, a xenon discharge tube is used). The optical fiber 4-2 is bent once into a semicircular shape. As you can see from this diagram, the diameter of the song is 5
When M, the transmittance of cladding mode light is 1/14 of that of propagation mode light. Although the propagation mode light intensity is also reduced to about 1/3, the cladding mode light is reduced to about 1/40 and can be almost completely eliminated.
このようにして、第−曲げ部4−5でクラッドモードが
除去された後、第二曲は部4−6で曲げ放射により伝播
モード光が放出される。この光を受光器4−4により受
光する。In this way, after the cladding mode is removed at the first bending section 4-5, propagation mode light is emitted by bending radiation at the second bending section 4-6. This light is received by the light receiver 4-4.
以上のようにして、同一の測定系で接続前に基準値を求
め、接続後に再度、接続損失に対応する受光値を求める
。この接続後に測定した値を基準値で正規化することK
よシ、第−曲げ部4−5.第二曲げ部4−6の状態、照
明器4−9や受光器4−4の配置状態、さらに光ファイ
バ心線の被覆の色や構造にも影響されることのない、損
失と一対一に対応した値を得ることができる。あらかじ
めこの正規化された値と接続損失の関係を求めておき、
その関係をもとに接続損失を求めることが可能である。As described above, the reference value is determined before connection using the same measurement system, and the light reception value corresponding to the connection loss is determined again after connection. After this connection, normalize the measured value with the reference value.
Okay, first bending part 4-5. One-on-one with loss, unaffected by the state of the second bending part 4-6, the arrangement of the illuminator 4-9 and receiver 4-4, and the color and structure of the optical fiber coating. You can get the corresponding value. Find the relationship between this normalized value and the connection loss in advance, and
It is possible to determine the connection loss based on that relationship.
第7図に測定例を示す。従来のパワーモニタ法による測
定で求めた接続損失に対して、本方法により求めた正規
化された値を示す。照明器4−9にクセノン放電管、受
光器4−4に光電増幅管を用い、第−曲は部4−5.第
二曲は部4−6ともに曲は直径は5順において測定した
結果である。本図かられかるように、0.5dB以下の
低損失接続に対して±0.05dB程度の高い損失測定
精度が得られる。Figure 7 shows an example of measurement. The normalized value obtained using this method is shown for the connection loss obtained by measurement using the conventional power monitoring method. A xenon discharge tube is used as the illuminator 4-9, and a photoamplifier tube is used as the receiver 4-4. The second track is the result of measuring the diameters in 5 order for both sections 4-6. As can be seen from this figure, a high loss measurement accuracy of about ±0.05 dB can be obtained for a low loss connection of 0.5 dB or less.
以上の例では、照明器4−9にクセノン放電管を使用し
た例のみを説明しだが、写真撮影等に用いられるストロ
ボ発光球やパルスレーザ−を使用することができる。受
光器4−4には光電増幅管以外にAPDを用いることが
可能である。まだ、以上の例では、第−曲げ部4−5.
第二曲げ部4−6の曲げ直径を5Nに設定した例のみを
説明したが、曲けによる光ファイバへの機械的損傷が心
配される。In the above example, only an example in which a xenon discharge tube is used as the illuminator 4-9 has been described, but a strobe light emitting bulb or a pulse laser used for photography etc. can also be used. It is possible to use an APD in addition to a photoamplifier tube for the light receiver 4-4. In the above example, the third bending portion 4-5.
Although only an example in which the bending diameter of the second bending portion 4-6 is set to 5N has been described, there is a concern that mechanical damage to the optical fiber due to bending may occur.
これをさけるには、曲げ径を大きくして曲げを数箇所設
ければよい。このようにすれば、光ファイバに損傷を与
えることなく、前記の如きクラッドモードの除去や伝播
モードの曲げ放射を実現できることは明らかである。To avoid this, the bending diameter may be increased and bends may be provided at several locations. It is clear that by doing this, it is possible to eliminate the cladding mode as described above and bend the propagation mode to emit radiation without damaging the optical fiber.
(発明の効果)
以上説明したように、本発明は、接続点に光を照射し接
続点の近くに曲げ部を2箇所用意し、接続点に近い第−
曲げ部で測定に不要な光を除去し、第二曲げ部で損失に
対応した光を放出させ、その光を受光する方法であるた
め、接続点の近傍のみで接続損失を高精度にかつ高速に
測定することができる利点がある。(Effects of the Invention) As explained above, the present invention irradiates the connection point with light, prepares two bent portions near the connection point, and
This method removes unnecessary light for measurement at the bending part, emits light corresponding to the loss at the second bending part, and receives that light, so it is possible to measure connection loss with high accuracy and high speed only in the vicinity of the connection point. There are benefits that can be measured.
また、仮接続も不要であシ、接続点以外の場所に作業者
測定器等を必要としないので、測定に要するコストを大
幅に下げることができる。さらに、本方法によれば、損
失測定装置と光ファイバの接続装置の一体化が極めて容
易であるという利点を有する。In addition, there is no need for temporary connections, and there is no need for a worker's measuring device or the like at a location other than the connection point, so the cost required for measurement can be significantly reduced. Furthermore, this method has the advantage that it is extremely easy to integrate the loss measuring device and the optical fiber connecting device.
第1図は従来の接続損失測定方法を説明するための配置
図、第2図は光ファイバ接続部から伝播光が漏洩する状
態を示す縦断面略図、第3図は本発明の基本的原理を示
す縦断面図、第4図は本発明の実施例を示す配置図、第
5図は接続前の測定において端面間隔と受光量の関係を
示す特性図、第6図は第−曲げ部における曲げ直径と定
常モード光の透過率およびクラッドモード光の透過率の
関係の測定結果を示す特性図、第7図は本発明による測
定値(規格値)と従来の透過光モニタ法によシ測定した
接続損失値との対応を示す特性図である。
1−1・・・接続点前方の光ファイバ、1−2・・・接
続点後”0光7″6パ・ ”−3°゛°光ゞ・ ”−“
°°受 (。)光器、1−5・・・仮接続点、1−6
・・・接続点、2−1・・・光7アイバ、2−2・・・
コア、2−3・・・伝播2−5・・・接続点、
゛
3−1・・・光ファイバ、 3−2・・・コア、3−3
・・・伝播4−3・・・接続点、4−4・・・受光器、
4−5・・・第−曲げ部、 4−6・・・第二曲げ部、
4−7・・・第−曲げ (d)部で放射される光、4
−8・・・第二曲げ部で放射される光、4−9・・・照
明器、4−10・・・接続部に照射される光。Fig. 1 is a layout diagram for explaining the conventional splice loss measurement method, Fig. 2 is a schematic vertical cross-sectional view showing the state in which propagating light leaks from the optical fiber connection, and Fig. 3 is a diagram illustrating the basic principle of the present invention. 4 is a layout diagram showing an embodiment of the present invention, FIG. 5 is a characteristic diagram showing the relationship between the end face spacing and the amount of light received during measurement before connection, and FIG. A characteristic diagram showing the measurement results of the relationship between the diameter and the transmittance of steady mode light and the transmittance of cladding mode light. Figure 7 shows the measured values (standard values) according to the present invention and those measured by the conventional transmitted light monitoring method. FIG. 3 is a characteristic diagram showing correspondence with connection loss values. 1-1...Optical fiber in front of the connection point, 1-2...After the connection point "0 light 7"6p."-3°゛°light."-"
°°Reception (.) Optical device, 1-5...Temporary connection point, 1-6
...Connection point, 2-1...Hikari 7 eyeball, 2-2...
Core, 2-3... Propagation 2-5... Connection point,
゛3-1...Optical fiber, 3-2...Core, 3-3
... Propagation 4-3... Connection point, 4-4... Light receiver,
4-5...First bending part, 4-6...Second bending part,
4-7...Light emitted at the -th bend (d) part, 4
-8...Light emitted at the second bending part, 4-9...Illuminator, 4-10...Light irradiated to the connection part.
Claims (1)
曲げ部を2個所設け、そのうち接続点から遠い方の曲げ
部に受光器を配置し、接続作業点に照明器を固定して配
置し、接続前の光ファイバ端部に前記照明器で光を照射
し、前記受光器で受光した光量と前記一対の光ファイバ
の相互接続後に再度前記照明器で該相互接続の接続部に
光を照射して前記受光器で受光した光量とを比較するこ
とにより、前記一対の光ファイバの接続損失を測定する
光ファイバ接続損失測定方法。One of the pair of optical fibers to be connected is provided with two bent portions, a light receiver is placed at the bent portion farther from the connection point, and an illuminator is fixedly placed at the connection work point, The illuminator irradiates the end of the optical fiber before connection with light, and after the amount of light received by the light receiver and the pair of optical fibers are interconnected, the illuminator irradiates the connection part of the interconnection with light again. An optical fiber splice loss measuring method for measuring splice loss of the pair of optical fibers by comparing the amount of light received by the light receiver.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP12640084A JPS617436A (en) | 1984-06-21 | 1984-06-21 | Method for measuring connection loss of optical fiber |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP12640084A JPS617436A (en) | 1984-06-21 | 1984-06-21 | Method for measuring connection loss of optical fiber |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS617436A true JPS617436A (en) | 1986-01-14 |
Family
ID=14934213
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP12640084A Pending JPS617436A (en) | 1984-06-21 | 1984-06-21 | Method for measuring connection loss of optical fiber |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS617436A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007303863A (en) * | 2006-05-09 | 2007-11-22 | Nippon Telegr & Teleph Corp <Ntt> | Connection loss determination method in optical fiber connection point |
-
1984
- 1984-06-21 JP JP12640084A patent/JPS617436A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007303863A (en) * | 2006-05-09 | 2007-11-22 | Nippon Telegr & Teleph Corp <Ntt> | Connection loss determination method in optical fiber connection point |
JP4702846B2 (en) * | 2006-05-09 | 2011-06-15 | 日本電信電話株式会社 | Connection loss judgment method at optical fiber connection point |
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