JPH08210944A - Optical fiber inspection device - Google Patents
Optical fiber inspection deviceInfo
- Publication number
- JPH08210944A JPH08210944A JP7015719A JP1571995A JPH08210944A JP H08210944 A JPH08210944 A JP H08210944A JP 7015719 A JP7015719 A JP 7015719A JP 1571995 A JP1571995 A JP 1571995A JP H08210944 A JPH08210944 A JP H08210944A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- signal
- mixer
- analyzer
- analyzed
- 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.)
- Granted
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- Testing Of Optical Devices Or Fibers (AREA)
Abstract
Description
【発明の詳細な説明】Detailed Description of the Invention
【０００１】[0001]
【産業上の利用分野】本発明は、光ファイバなどの検査
装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection device for optical fibers and the like.
【０００２】[0002]
【従来の技術】光ファイバ検査装置には、よく知られて
いるＯＴＤＲ（Optical Time DomainReflectmeter）の
他に、ＯＦＤＲ（Optical Frequency Domain Reflectme
ter）がある。図６にファイバ形干渉計によるＯＦＤＲ
のブロック図を示す。2. Description of the Related Art In addition to a well-known OTDR (Optical Time Domain Reflectmeter), an optical fiber inspection apparatus includes an OFDR (Optical Frequency Domain Reflectme
ter). Figure 6 OFDR with fiber interferometer
The block diagram of is shown.
【０００３】図６において、電気・光変換器（以下Ｅ／
Ｏ変換器という）３から発せられる光（例えばレーザ
光）は、分配器２を介して与えられるスイープ発振器１
の出力により駆動され、出力光の周波数が掃引されるよ
うに制御されている。この出力光は光カプラ４を経て被
測定対象の光ファイバ（以下ＤＵＴ（Device Under Tes
t ）５に入り、ＤＵＴ５中の障害点（例えば、破断面）
等で反射する。その反射光は光カプラ４を経て光・電気
変換器（Ｏ／Ｅ変換器）６に入り、電気信号に変換さ
れ、ミキサ７に入る。In FIG. 6, an electric / optical converter (hereinafter referred to as E /
The light (for example, laser light) emitted from the O converter 3 is supplied to the sweep oscillator 1 through the distributor 2.
It is driven by the output of the output light and is controlled so that the frequency of the output light is swept. The output light passes through the optical coupler 4 and is measured by an optical fiber (hereinafter referred to as DUT (Device Under Tes).
t) 5 is entered and the obstacle point in DUT 5 (eg fracture surface)
And so on. The reflected light enters the optical / electrical converter (O / E converter) 6 through the optical coupler 4, is converted into an electric signal, and enters the mixer 7.
【０００４】ミキサ７にはまた先のスイープ発振器１の
出力が分配器２を経由して入力されており、２つの入力
信号の差周波数の信号を出力する。この信号は周波数ア
ナライザ８に入力され、その差周波数が解析される。The output of the sweep oscillator 1 is also input to the mixer 7 via the distributor 2, and outputs a signal having a difference frequency between the two input signals. This signal is input to the frequency analyzer 8 and its difference frequency is analyzed.
【０００５】ここでスイープ発振器１を、単位時間（Δ
ｔ）当たりΔｆの周波数変化となるようにリニアに掃引
する。ミキサ７の２つの入力周波数差は遅れ時間差に比
例する。遅れ時間差はＤＵＴ５内の障害点までの距離に
比例することから、周波数解析を行うことにより、障害
点までの距離を知ることができ、また信号の大きさから
障害点での反射量すなわち障害点の大きさを知ることが
できる。Here, the sweep oscillator 1 is set to a unit time (Δ
The sweep is performed linearly so that the frequency changes by Δf per t). The difference between the two input frequencies of the mixer 7 is proportional to the delay time difference. Since the delay time difference is proportional to the distance to the fault point in the DUT 5, the distance to the fault point can be known by performing frequency analysis, and the amount of reflection at the fault point, that is, the fault point can be determined from the signal size. You can know the size of.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、近距離
にある障害点からの反射光による信号は、ミキサ７の出
力では低周波となり、次のような問題があった。 １／ｆノイズ等低周波成分にはノイズが多く含まれ、
強度の小さい低周波信号を解析するのは困難である。 周波数アナライザとして、一般的なスペクトラムアナ
ライザは低周波信号を解析し難い。 また、遠距離にある障害点からの反射光による信号（周
波数アナライザの被測定信号）は高周波となりすぎて測
定困難になる場合がある。However, the signal due to the reflected light from the obstacle located at a short distance has a low frequency at the output of the mixer 7 and has the following problems. Low frequency components such as 1 / f noise contain a lot of noise,
It is difficult to analyze low-frequency signals with low intensity. As a frequency analyzer, a general spectrum analyzer is difficult to analyze low frequency signals. In addition, the signal (the signal under measurement of the frequency analyzer) due to the reflected light from the obstacle point at a long distance may become too high in frequency to make measurement difficult.
【０００７】本発明の目的は、解析信号であるミキサの
出力を周波数シフトさせることにより上記問題点を解決
し、近距離または遠距離にある障害点を検出することの
できる光ファイバ検査装置を提供することにある。An object of the present invention is to provide an optical fiber inspection apparatus which can solve the above problems by frequency-shifting the output of a mixer which is an analytic signal and can detect a fault point at a short distance or a long distance. To do.
【０００８】[0008]
【課題を解決するための手段】このような目的を達成す
るために本発明では、スイープ発振器とこれにより強度
変調されるＥ／Ｏ変換器を備え、この出力光を光カプラ
を介して被測定対象に入射し被測定対象内で反射された
光をＯ／Ｅ変換器により電気信号に変換し、この電気信
号とスイープ発振器出力とをミキサでミキシングして差
周波数の信号を得、この差周波数を周波数アナライザで
解析することにより、被測定対象内の反射点までの距離
と反射量を検出するように構成された光ファイバ検査装
置において、周波数アナライザによる被解析信号の周波
数を測定可能な周波数域に周波数シフトするための手段
を備えたことを特徴とする。In order to achieve such an object, the present invention comprises a sweep oscillator and an E / O converter whose intensity is modulated by the sweep oscillator, and the output light is measured through an optical coupler. The light incident on the object and reflected within the object to be measured is converted into an electric signal by the O / E converter, and the electric signal and the output of the sweep oscillator are mixed by a mixer to obtain a signal having a difference frequency. The frequency range in which the frequency of the signal under analysis can be measured by the frequency analyzer in an optical fiber inspection device configured to detect the distance to the reflection point and the amount of reflection in the object under measurement by analyzing the Is provided with a means for frequency shifting.
【０００９】[0009]
【作用】ＤＵＴ入力端に光ファイバを接続することによ
り、被測定対象からの反射光の戻り時間を長くして、周
波数アナライザによる被解析信号の周波数を高周波側に
周波数シフトする。あるいはＯ／Ｅ変換器出力にアナロ
グデレイ素子を接続して信号を遅延し、同様に周波数ア
ナライザによる被解析信号の周波数を高周波側に周波数
シフトする。あるいはまたミキサの出力を発振器より出
力される所定の周波数の信号とミキシングして周波数の
加算を行い、同様に周波数アナライザによる被解析信号
の周波数を高周波側に周波数シフトする。周波数アナラ
イザによる被解析信号の周波数を低周波側に周波数シフ
トする場合は、スイープ発振器の出力信号をアナログデ
レイ素子により遅延してミキサに入力する。あるいは第
２のミキサを用意し、第１のミキサの出力と所定の周波
数信号を発生する発振器の出力との周波数の差の信号を
得て周波数アナライザに与える。By connecting an optical fiber to the DUT input end, the return time of the reflected light from the object to be measured is lengthened and the frequency of the signal to be analyzed by the frequency analyzer is frequency shifted to the high frequency side. Alternatively, an analog delay element is connected to the output of the O / E converter to delay the signal, and similarly the frequency of the signal to be analyzed by the frequency analyzer is frequency shifted to the high frequency side. Alternatively, the output of the mixer is mixed with a signal of a predetermined frequency output from the oscillator to add the frequencies, and similarly the frequency of the signal to be analyzed by the frequency analyzer is frequency shifted to the high frequency side. When the frequency of the signal to be analyzed by the frequency analyzer is frequency-shifted to the low frequency side, the output signal of the sweep oscillator is delayed by the analog delay element and input to the mixer. Alternatively, a second mixer is prepared, and a signal of the difference in frequency between the output of the first mixer and the output of the oscillator that generates a predetermined frequency signal is obtained and given to the frequency analyzer.
【００１０】[0010]
【実施例】以下図面を用いて本発明を詳しく説明する。
図１は本発明に係る光ファイバ検査装置の一実施例を示
す構成図である。なお、図６と同等部分には同一符号を
付してある。本発明は周波数アナライザによる被解析信
号の周波数を測定可能な周波数域に周波数シフトするた
めの手段を有することを特徴とするものである。The present invention will be described in detail below with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of an optical fiber inspection apparatus according to the present invention. The same parts as those in FIG. 6 are designated by the same reference numerals. The present invention is characterized by having means for frequency-shifting the frequency of the signal to be analyzed by the frequency analyzer to a measurable frequency range.
【００１１】図１においては、その手段が光カプラ４と
ＤＵＴ５の間に接続した光ファイバ９である。ここで、
スイープ発振器１は１ＧＨｚ／ｓｅｃの割合（掃引レー
ト）で掃引するものとする。ＤＵＴ５が屈折率ｎ＝１．
５の光ファイバである場合、ファイバ内を１ｍ光が往復
する時間ｔは、 ｔ＝２×ｎ／Ｃ≒１×１０-8（ｓｅｃ） となる。In FIG. 1, the means is an optical fiber 9 connected between the optical coupler 4 and the DUT 5. here,
The sweep oscillator 1 sweeps at a rate (sweep rate) of 1 GHz / sec. The DUT 5 has a refractive index n = 1.
In the case of 5 optical fibers, the time t for 1 m of light to make a round trip in the fiber is t = 2 × n / C≈1 × 10 −8 (sec).
【００１２】スイープ発振器１の掃引レートから、この
時間ｔにより１０Ｈｚの周波数差が生じる。したがっ
て、周波数アナライザ８で差周波数を解析することによ
り１０Ｈｚ当たり１ｍで障害点の位置を検出することが
できる。ここで、ＤＵＴ５が接続される端面からの反射
光による信号（換言すれば、周波数アナライザ８の被測
定信号）を０Ｈｚとする。ＤＵＴ５が１ｍの光ファイバ
であれば、ファイバの開放端からの反射光による信号は
１０Ｈｚとなる。Due to the sweep rate of the sweep oscillator 1, a frequency difference of 10 Hz occurs due to this time t. Therefore, by analyzing the difference frequency with the frequency analyzer 8, the position of the fault point can be detected at 1 m per 10 Hz. Here, the signal (in other words, the signal under measurement of the frequency analyzer 8) due to the reflected light from the end face to which the DUT 5 is connected is set to 0 Hz. If the DUT 5 is an optical fiber of 1 m, the signal due to the reflected light from the open end of the fiber will be 10 Hz.
【００１３】追加の光ファイバ９として例えば１０ｍの
ものを用意すると、周波数アナライザ８での被解析周波
数は１００Ｈｚ分高周波側にシフトしたものとなる。つ
まり、光ファイバ９が１０ｍで、ＤＵＴ５が１ｍの光フ
ァイバであれば、ＤＵＴ５の開放端からの反射光による
信号（周波数アナライザの被測定信号）は１１０Ｈｚと
なる。If an additional optical fiber 9 of 10 m, for example, is prepared, the analyzed frequency in the frequency analyzer 8 is shifted to the high frequency side by 100 Hz. That is, if the optical fiber 9 is 10 m and the DUT 5 is 1 m, the signal (measured signal of the frequency analyzer) due to the reflected light from the open end of the DUT 5 is 110 Hz.
【００１４】図２は本発明の他の実施例図であり、周波
数アナライザによる被解析信号の周波数を測定可能な周
波数域に周波数シフトするための手段として、Ｏ／Ｅ変
換器６とミキサ７の間に接続されたアナログデレイ素子
１０を用いた例である。アナログデレイ素子１０として
例えば１００ｎｓｅｃのものを用いると、被解析周波数
は１００Ｈｚ分高周波側にシフトする（スイープ発振器
１が１ＧＨｚ／ｓｅｃの掃引レートであるから、１００
ｎｓｅｃの遅れは１００Ｈｚとなる）。ＤＵＴ５が１ｍ
の光ファイバである場合には、光ファイバの開放端から
の反射光による信号（周波数アナライザの被測定信号）
は１１０Ｈｚとなる。FIG. 2 is a diagram showing another embodiment of the present invention. As means for frequency-shifting the frequency of the signal to be analyzed by the frequency analyzer to a measurable frequency range, an O / E converter 6 and a mixer 7 are provided. This is an example using the analog delay element 10 connected between them. If, for example, 100 nsec is used as the analog delay element 10, the analyzed frequency shifts to the high frequency side by 100 Hz (since the sweep oscillator 1 has a sweep rate of 1 GHz / sec, 100
The delay of nsec becomes 100 Hz). DUT5 is 1m
Signal of the reflected light from the open end of the optical fiber (measured signal of the frequency analyzer)
Is 110 Hz.
【００１５】図３は本発明の更に他の実施例図であり、
周波数アナライザによる被解析信号の周波数を測定可能
な周波数域に周波数シフトするための手段として、第２
のミキサ１１と発振器１２を用いた例である。ミキサ１
１を第１のミキサ７と周波数アナライザ８の間に接続
し、ミキサ１１で第１のミキサ７の出力と発振器１２の
出力をミキシングする。発振器１２の出力周波数を例え
ば１００Ｈｚとし、ミキサ１１でミキサ７の出力周波数
に加算することにより、被解析周波数を１００Ｈｚ分高
周波側にシフトすることができる。ＤＵＴ５を１ｍの光
ファイバとすると、光ファイバの開放端からの反射光に
よる信号（周波数アナライザの被測定信号）は１１０Ｈ
ｚとなる。FIG. 3 is a diagram showing another embodiment of the present invention.
As means for frequency-shifting the frequency of the analyzed signal by the frequency analyzer to a measurable frequency range,
This is an example using the mixer 11 and the oscillator 12 of. Mixer 1
1 is connected between the first mixer 7 and the frequency analyzer 8, and the mixer 11 mixes the output of the first mixer 7 and the output of the oscillator 12. By setting the output frequency of the oscillator 12 to 100 Hz and adding it to the output frequency of the mixer 7 by the mixer 11, the analyzed frequency can be shifted to the high frequency side by 100 Hz. If the DUT 5 is an optical fiber of 1 m, the signal (measured signal of the frequency analyzer) due to the reflected light from the open end of the optical fiber is 110H.
z.
【００１６】図４は周波数アナライザによる被解析信号
の周波数を測定可能な周波数域に周波数シフトするため
の手段として、アナログデレイ素子１３を用いた例であ
る。これにより周波数アナライザ８による被解析信号の
周波数を低周波側にシフトさせることができる。アナロ
グデレイ素子１３として例えば５０μｓｅｃのものを用
いると、被解析周波数は５０ＫＨｚ分低周波側にシフト
する。ＤＵＴ５を１０Ｋｍの光ファイバとすると、光フ
ァイバ開放端からの反射光による信号（周波数アナライ
ザの被測定信号）は５０ＫＨｚとなる。FIG. 4 shows an example in which the analog delay element 13 is used as a means for frequency shifting the frequency of the signal to be analyzed by the frequency analyzer to a measurable frequency range. As a result, the frequency of the signal to be analyzed by the frequency analyzer 8 can be shifted to the low frequency side. When the analog delay element 13 having, for example, 50 μsec is used, the analyzed frequency is shifted to the low frequency side by 50 KHz. When the DUT 5 is an optical fiber of 10 Km, the signal (the signal under measurement of the frequency analyzer) due to the reflected light from the open end of the optical fiber is 50 KHz.
【００１７】図５は周波数アナライザによる被解析信号
の周波数を測定可能な周波数域に周波数シフトするため
の手段として、第１のミキサ７と周波数アナライザ８の
間に第２のミキサ１４と発振器１５を設けた例である。
発振器１５として例えば５０ＫＨｚを用意し、ミキサ１
４による差周波数を利用すると、被解析周波数は５０Ｋ
Ｈｚ分低周波シフトする。ＤＵＴ５を１０Ｋｍの光ファ
イバとすると、光ファイバ開放端からの反射光による信
号（周波数アナライザの被測定信号）は５０ＫＨｚとな
る。FIG. 5 shows a second mixer 14 and an oscillator 15 between the first mixer 7 and the frequency analyzer 8 as means for frequency-shifting the frequency of the signal to be analyzed by the frequency analyzer to a measurable frequency range. This is an example provided.
For example, 50 KHz is prepared as the oscillator 15, and the mixer 1
If the difference frequency according to 4 is used, the analyzed frequency is 50K.
Low frequency shift by Hz. When the DUT 5 is an optical fiber of 10 Km, the signal (the signal under measurement of the frequency analyzer) due to the reflected light from the open end of the optical fiber is 50 KHz.
【００１８】[0018]
【発明の効果】以上説明したように本発明によれば、光
ファイバや、アナログデレイ素子、第２のミキサと発振
器を用いて、解析信号を高周波側または低周波側にシフ
トさせることができ、高周波側にシフトさせた場合は近
距離にある障害点を検出でき、低周波側にシフトさせた
場合は遠距離にある障害点を検出することができる。As described above, according to the present invention, an analytic signal can be shifted to a high frequency side or a low frequency side by using an optical fiber, an analog delay element, a second mixer and an oscillator, When shifting to the high frequency side, a fault point at a short distance can be detected, and when shifting to the low frequency side, a fault point at a long distance can be detected.
【図１】本発明に係る光ファイバ検査装置の一実施例を
示す構成図FIG. 1 is a configuration diagram showing an embodiment of an optical fiber inspection apparatus according to the present invention.
【図２】本発明の他の実施例を示す構成図FIG. 2 is a configuration diagram showing another embodiment of the present invention.
【図３】本発明の更に他の実施例を示す構成図FIG. 3 is a configuration diagram showing still another embodiment of the present invention.
【図４】本発明の更に他の実施例を示す構成図FIG. 4 is a configuration diagram showing still another embodiment of the present invention.
【図５】本発明の更に他の実施例を示す構成図FIG. 5 is a configuration diagram showing still another embodiment of the present invention.
【図６】従来の光ファイバ検査装置の一例を示す構成図
である。FIG. 6 is a configuration diagram showing an example of a conventional optical fiber inspection apparatus.
１ スイープ発振器 ２ 分配器 ３ Ｅ／Ｏ ４ 光カプラ ５ ＤＵＴ ６ Ｏ／Ｅ ７，１１ ミキサ ８ 周波数アナライザ ９ 光ファイバ １０，１３ アナログデレイ素子 １２，１５ 発振器 1 Sweep Oscillator 2 Divider 3 E / O 4 Optical Coupler 5 DUT 6 O / E 7,11 Mixer 8 Frequency Analyzer 9 Optical Fiber 10,13 Analog Delay Element 12,15 Oscillator
───────────────────────────────────────────────────── フロントページの続き (72)発明者 立川 義彦 東京都武蔵野市中町２丁目９番32号 横河 電機株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiko Tachikawa 2-3-9 Nakamachi, Musashino-shi, Tokyo Yokogawa Electric Co., Ltd.
Claims (6)
るＥ／Ｏ変換器を備え、この出力光を光カプラを介して
被測定対象に入射し被測定対象内で反射された光をＯ／
Ｅ変換器により電気信号に変換し、この電気信号とスイ
ープ発振器出力とをミキサでミキシングして差周波数の
信号を得、この差周波数を周波数アナライザで解析する
ことにより、被測定対象内の反射点までの距離と反射量
を検出するように構成された光ファイバ検査装置におい
て、 周波数アナライザによる被解析信号の周波数を測定可能
な周波数域に周波数シフトするための手段を具備したこ
とを特徴とする光ファイバ検査装置。1. A sweep oscillator and an E / O converter, the intensity of which is modulated by the sweep oscillator, are provided. The output light is made incident on an object to be measured through an optical coupler, and the light reflected in the object to be measured is O / O.
The electric signal is converted by the E converter, the electric signal and the output of the sweep oscillator are mixed by a mixer to obtain a signal of a difference frequency, and the difference frequency is analyzed by a frequency analyzer to obtain a reflection point in the object to be measured. An optical fiber inspection device configured to detect the distance to and the amount of reflection, characterized by including means for frequency-shifting the frequency of the signal under analysis by a frequency analyzer to a measurable frequency range. Fiber inspection equipment.
周波数を測定可能な周波数域に周波数シフトするための
手段が、前記光カプラと被測定対象の間に接続された光
ファイバであり、前記周波数アナライザによる被解析信
号の周波数を高周波側にシフトするように構成したこと
を特徴とする請求項１記載の光ファイバ検査装置。2. A means for frequency-shifting the frequency of a signal to be analyzed by the frequency analyzer to a measurable frequency range is an optical fiber connected between the optical coupler and the object to be measured. 2. The optical fiber inspection apparatus according to claim 1, wherein the frequency of the signal to be analyzed according to is shifted to a high frequency side.
周波数を測定可能な周波数域に周波数シフトするための
手段が、前記Ｏ／Ｅ変換器と前記ミキサの間に接続され
たアナログデレイ素子であり、前記周波数アナライザに
よる被解析信号の周波数を高周波側にシフトするように
構成したことを特徴とする請求項１記載の光ファイバ検
査装置。3. The means for frequency-shifting the frequency of the signal to be analyzed by the frequency analyzer to a measurable frequency range is an analog delay element connected between the O / E converter and the mixer, 2. The optical fiber inspection device according to claim 1, wherein the frequency of the signal to be analyzed by the frequency analyzer is shifted to a high frequency side.
周波数を測定可能な周波数域に周波数シフトするための
手段が、前記ミキサと前記周波数アナライザの間に接続
された第２のミキサとこのミキサに加える信号を発生す
る発振器から成り、前記周波数アナライザによる被解析
信号の周波数を高周波側にシフトするように構成したこ
とを特徴とする請求項１記載の光ファイバ検査装置。4. Means for frequency shifting the frequency of the signal under analysis by the frequency analyzer to a measurable frequency range is applied to the mixer and a second mixer connected between the mixer and the frequency analyzer. 2. The optical fiber inspection apparatus according to claim 1, wherein the optical fiber inspection apparatus comprises an oscillator that generates a signal, and is configured to shift the frequency of the signal to be analyzed by the frequency analyzer to the high frequency side.
周波数を測定可能な周波数域に周波数シフトするための
手段が、前記スイープ発振器の出力信号を遅延させて前
記ミキサに与えるアナログデレイ素子であり、前記周波
数アナライザによる被解析信号の周波数を低周波側にシ
フトするように構成したことを特徴とする請求項１記載
の光ファイバ検査装置。5. The means for frequency-shifting the frequency of the signal to be analyzed by the frequency analyzer to a measurable frequency range is an analog delay element for delaying the output signal of the sweep oscillator and giving it to the mixer, The optical fiber inspection apparatus according to claim 1, wherein the frequency of the signal to be analyzed by the frequency analyzer is shifted to the low frequency side.
周波数を測定可能な周波数域に周波数シフトするための
手段が、前記ミキサと前記周波数アナライザの間に接続
された第２のミキサとこのミキサに加える信号を発生す
る発振器から成り、前記第２のミキサにおいて２つの入
力の差周波数の信号を得、前記周波数アナライザによる
被解析信号の周波数を低周波側にシフトするように構成
したことを特徴とする請求項１記載の光ファイバ検査装
置。6. A second mixer connected between the mixer and the frequency analyzer and means for frequency-shifting the frequency of the signal to be analyzed by the frequency analyzer to a measurable frequency range are added to the mixer. The second mixer is configured to obtain a signal having a difference frequency between two inputs in the second mixer, and shift the frequency of the signal to be analyzed by the frequency analyzer to a low frequency side. The optical fiber inspection device according to claim 1.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01571995A JP3453745B2 (en) | 1995-02-02 | 1995-02-02 | Optical fiber inspection equipment |
| DE69632000T DE69632000T2 (en) | 1995-02-02 | 1996-01-30 | MEASURING DEVICE FOR OPTICAL FIBERS |
| DE0754939T DE754939T1 (en) | 1995-02-02 | 1996-01-30 | MEASURING DEVICE FOR OPTICAL FIBERS |
| EP96901143A EP0754939B1 (en) | 1995-02-02 | 1996-01-30 | Optical fibre detecting device |
| PCT/JP1996/000170 WO1996024038A1 (en) | 1995-02-02 | 1996-01-30 | Optical fibre detecting device |
| US08/727,377 US5844235A (en) | 1995-02-02 | 1996-01-30 | Optical frequency domain reflectometer for use as an optical fiber testing device |
| US09/039,944 US6008487A (en) | 1995-02-02 | 1998-03-16 | Optical-fiber inspection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01571995A JP3453745B2 (en) | 1995-02-02 | 1995-02-02 | Optical fiber inspection equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08210944A true JPH08210944A (en) | 1996-08-20 |
| JP3453745B2 JP3453745B2 (en) | 2003-10-06 |
Family
ID=11896577
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP01571995A Expired - Fee Related JP3453745B2 (en) | 1995-02-02 | 1995-02-02 | Optical fiber inspection equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3453745B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08219947A (en) * | 1995-02-09 | 1996-08-30 | Yokogawa Electric Corp | Inspection apparatus for optical fiber |
| JP2012501124A (en) * | 2008-08-29 | 2012-01-12 | テレフオンアクチーボラゲット エル エム エリクソン（パブル） | Fiber monitoring method in optical network |
| JP2013072872A (en) * | 2011-09-27 | 2013-04-22 | Chunghwa Telecom Co Ltd | Optical fiber network test method based on optical frequency domain reflection |
Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5347701A (en) * | 1976-10-13 | 1978-04-28 | Nippon Telegr & Teleph Corp <Ntt> | Optical sweep signal generator |
| JPS57118136A (en) * | 1981-01-14 | 1982-07-22 | Nippon Telegr & Teleph Corp <Ntt> | Fault searching method by optical fiber |
| JPH026724A (en) * | 1988-01-21 | 1990-01-10 | Hewlett Packard Co <Hp> | Method and apparatus for testing optical transmission medium |
| JPH03122538A (en) * | 1988-12-14 | 1991-05-24 | Centre Natl Rech Scient <Cnrs> | Method of analyzing guided optical element optical fiber or optical guide network by temporal reflector measurement and reflector apparatus |
| JPH03175333A (en) * | 1989-09-26 | 1991-07-30 | Yokogawa Electric Corp | Light transmission line measuring device |
| US5062703A (en) * | 1988-01-21 | 1991-11-05 | Hewlett-Packard Company | Method and apparatus for measuring the length of, or distances to discontinuities in, an optical transmission medium |
| JPH04248434A (en) * | 1991-02-04 | 1992-09-03 | Nippon Telegr & Teleph Corp <Ntt> | Remote tester of optical line |
| JPH05275782A (en) * | 1992-03-30 | 1993-10-22 | Nec Corp | Analog optical transmitter |
| JPH0653590A (en) * | 1992-07-31 | 1994-02-25 | Hitachi Ltd | Method for stabilizing optical fsk frequency displacement amount |
| JPH0666517A (en) * | 1992-06-30 | 1994-03-08 | Hewlett Packard Co <Hp> | Optical interferometer |
| JPH0674710A (en) * | 1992-05-27 | 1994-03-18 | Hewlett Packard Co <Hp> | Optical reflectometer |
| JPH075068A (en) * | 1993-06-17 | 1995-01-10 | Nippon Telegr & Teleph Corp <Ntt> | Light frequency region reflection measuring device |
| JPH07270841A (en) * | 1994-03-31 | 1995-10-20 | Ando Electric Co Ltd | Sweep optical frequency generator |
| JPH0854586A (en) * | 1994-08-10 | 1996-02-27 | Nippon Telegr & Teleph Corp <Ntt> | Light source for optical frequency sweeping |
| JPH08201225A (en) * | 1995-01-27 | 1996-08-09 | Yokogawa Electric Corp | Variable light frequency light source |
| JPH08220579A (en) * | 1995-02-10 | 1996-08-30 | Yokogawa Electric Corp | Strength modulating frequency variable light source |
| JPH08219947A (en) * | 1995-02-09 | 1996-08-30 | Yokogawa Electric Corp | Inspection apparatus for optical fiber |
-
1995
- 1995-02-02 JP JP01571995A patent/JP3453745B2/en not_active Expired - Fee Related
Patent Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5347701A (en) * | 1976-10-13 | 1978-04-28 | Nippon Telegr & Teleph Corp <Ntt> | Optical sweep signal generator |
| JPS57118136A (en) * | 1981-01-14 | 1982-07-22 | Nippon Telegr & Teleph Corp <Ntt> | Fault searching method by optical fiber |
| JPH026724A (en) * | 1988-01-21 | 1990-01-10 | Hewlett Packard Co <Hp> | Method and apparatus for testing optical transmission medium |
| US5062703A (en) * | 1988-01-21 | 1991-11-05 | Hewlett-Packard Company | Method and apparatus for measuring the length of, or distances to discontinuities in, an optical transmission medium |
| JPH03122538A (en) * | 1988-12-14 | 1991-05-24 | Centre Natl Rech Scient <Cnrs> | Method of analyzing guided optical element optical fiber or optical guide network by temporal reflector measurement and reflector apparatus |
| JPH03175333A (en) * | 1989-09-26 | 1991-07-30 | Yokogawa Electric Corp | Light transmission line measuring device |
| JPH04248434A (en) * | 1991-02-04 | 1992-09-03 | Nippon Telegr & Teleph Corp <Ntt> | Remote tester of optical line |
| JPH05275782A (en) * | 1992-03-30 | 1993-10-22 | Nec Corp | Analog optical transmitter |
| JPH0674710A (en) * | 1992-05-27 | 1994-03-18 | Hewlett Packard Co <Hp> | Optical reflectometer |
| JPH0666517A (en) * | 1992-06-30 | 1994-03-08 | Hewlett Packard Co <Hp> | Optical interferometer |
| JPH0653590A (en) * | 1992-07-31 | 1994-02-25 | Hitachi Ltd | Method for stabilizing optical fsk frequency displacement amount |
| JPH075068A (en) * | 1993-06-17 | 1995-01-10 | Nippon Telegr & Teleph Corp <Ntt> | Light frequency region reflection measuring device |
| JPH07270841A (en) * | 1994-03-31 | 1995-10-20 | Ando Electric Co Ltd | Sweep optical frequency generator |
| JPH0854586A (en) * | 1994-08-10 | 1996-02-27 | Nippon Telegr & Teleph Corp <Ntt> | Light source for optical frequency sweeping |
| JPH08201225A (en) * | 1995-01-27 | 1996-08-09 | Yokogawa Electric Corp | Variable light frequency light source |
| JPH08219947A (en) * | 1995-02-09 | 1996-08-30 | Yokogawa Electric Corp | Inspection apparatus for optical fiber |
| JPH08220579A (en) * | 1995-02-10 | 1996-08-30 | Yokogawa Electric Corp | Strength modulating frequency variable light source |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08219947A (en) * | 1995-02-09 | 1996-08-30 | Yokogawa Electric Corp | Inspection apparatus for optical fiber |
| JP2012501124A (en) * | 2008-08-29 | 2012-01-12 | テレフオンアクチーボラゲット エル エム エリクソン（パブル） | Fiber monitoring method in optical network |
| US8634713B2 (en) | 2008-08-29 | 2014-01-21 | Telefonaktiebolaget Lm Ericsson (Publ) | Fibre monitoring in optical networks |
| JP2013072872A (en) * | 2011-09-27 | 2013-04-22 | Chunghwa Telecom Co Ltd | Optical fiber network test method based on optical frequency domain reflection |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3453745B2 (en) | 2003-10-06 |
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