JPH0354292B2 - - Google Patents
Info
- Publication number
- JPH0354292B2 JPH0354292B2 JP24527883A JP24527883A JPH0354292B2 JP H0354292 B2 JPH0354292 B2 JP H0354292B2 JP 24527883 A JP24527883 A JP 24527883A JP 24527883 A JP24527883 A JP 24527883A JP H0354292 B2 JPH0354292 B2 JP H0354292B2
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- wavelength
- optical signal
- optical
- measurement
- 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
Links
- 239000013307 optical fiber Substances 0.000 claims description 38
- 230000003287 optical effect Effects 0.000 claims description 33
- 238000005259 measurement Methods 0.000 claims description 22
- 239000006185 dispersion Substances 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 12
- 230000010363 phase shift Effects 0.000 claims description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 230000001902 propagating effect Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
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
- G01M11/33—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter being disposed at one fibre or waveguide end-face, and a light receiver at the other end-face
- G01M11/333—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter being disposed at one fibre or waveguide end-face, and a light receiver at the other end-face using modulated input signals
-
- 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
- G01M11/33—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter being disposed at one fibre or waveguide end-face, and a light receiver at the other end-face
- G01M11/335—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter being disposed at one fibre or waveguide end-face, and a light receiver at the other end-face using two or more input wavelengths
Description
【発明の詳細な説明】
本発明は位相シフト法による光フアイバの分散
特性測定方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the dispersion characteristics of an optical fiber using a phase shift method.
ある長さを持つ光フアイバの一端にスペクトル
の広がりをもつた光をパルス化した光パルスを入
射させると、もう一方の端面から出射する光は、
入射した光のパルスの時間幅より広がつた光のパ
ルスになる。これは光フアイバの分散に起因する
もので、この分散特性により光フアイバの伝送帯
域がほぼ決定される。従つて、光フアイバを用い
た光通信では、使用波長帯域における光フアイバ
の分散特性を高精度に測定する方式が重要となつ
てくる。 When an optical pulse of light with a broadened spectrum is input into one end of an optical fiber of a certain length, the light emitted from the other end is
The light pulse becomes wider than the time width of the incident light pulse. This is due to the dispersion of the optical fiber, and the transmission band of the optical fiber is approximately determined by this dispersion characteristic. Therefore, in optical communications using optical fibers, it is important to have a method for measuring the dispersion characteristics of optical fibers with high accuracy in the wavelength band used.
第１図は、従来の位相シフト法による分散特性
測定装置であり、同図を用いて従来の分散特性測
定方法並びに装置について説明する。第１図にお
いて、可変波長光源２は変調信号発生器１により
発生される正弦波等で振幅変調され、その被変調
光は波長計３で正確な波長を測定するとともに、
光分岐器４を介して二つの被変調光に分岐され
る。この被変調光の一方は、被測定光フアイバ５
を伝搬した後、光電変換器６に入り、他方は直接
に光電変換器７に入つて、それぞれの光信号が電
気信号に変換された各々の電気信号に含まれる変
調信号の位相差が位相比較器８で検出される。
尚、可変波長光源２としては数個の波長の異なる
半導体レーザのアレイから光スイツチ等により、
順次所要波長の光を選択抽出して得るか、あるい
は広範囲な発光波長分布を有する発光ダイオード
の出射光を分光器等で選択抽出して得ている。 FIG. 1 shows a conventional dispersion characteristic measuring device using a phase shift method, and the conventional dispersion characteristic measuring method and device will be explained using this figure. In FIG. 1, a variable wavelength light source 2 is amplitude-modulated by a sine wave or the like generated by a modulation signal generator 1, and the wavelength of the modulated light is measured by a wavelength meter 3, and
The light is split into two modulated lights via the optical splitter 4. One of the modulated lights is connected to the optical fiber 5 to be measured.
After propagating, the optical signal enters a photoelectric converter 6, and the other directly enters a photoelectric converter 7, where each optical signal is converted into an electrical signal.The phase difference between the modulated signals contained in each electrical signal is determined by phase comparison. Detected by device 8.
In addition, as the variable wavelength light source 2, an array of several semiconductor lasers with different wavelengths is used, using an optical switch or the like.
It is obtained by sequentially selectively extracting light of required wavelengths, or by selectively extracting light emitted from a light emitting diode having a wide emission wavelength distribution using a spectrometer or the like.
今、変調信号周波数を（Hz）、検出位相差を
Δθ度とすると、ある波長λk（nm）の光が被測定
光フアイバ５を伝搬するのに要する時間Δtk（ｐ
−sec）は、
Δtk＝１／×Δθ／360×1012（ｐ−sec） …(1)
となる。さらに、被測定光フアイバ５の長さをＬ
（Km）とすると、単位長さ当りの群遅延時間は、
τk＝Δtk／Ｌ（ｐ−sec／Km） …(2)
となる。従つて、各波長に対するΔθを測定し、
(1)式及び(2)式からτkを計算して、第２図ａに示す
ような所望の波長帯域における群遅延特性を得
て、更にdτk／dλを計算することにより、第２図
ｂの如く分散特性が求められる。しかしながら、
上記の従来の測定方法では、温度変化による光フ
アイバの伸びに対する対策が何ら施されていない
ため、次に述べるように極めて大きな誤差を含ん
だものとなる。 Now, if the modulation signal frequency is (Hz) and the detection phase difference is Δθ degrees, then the time required for light with a certain wavelength λ k (nm) to propagate through the optical fiber 5 under test Δt k (p
−sec) becomes Δt k =1/×Δθ/360×10 12 (p−sec) (1). Furthermore, the length of the optical fiber 5 to be measured is L
(Km), the group delay time per unit length is τ k =Δt k /L (p-sec/Km) (2). Therefore, measure Δθ for each wavelength,
By calculating τ k from equations (1) and (2) to obtain the group delay characteristic in the desired wavelength band as shown in Figure 2a, and further calculating dτ k /dλ, the second The dispersion characteristics are determined as shown in Figure b. however,
The conventional measurement method described above does not take any measures against the elongation of the optical fiber due to temperature changes, and therefore contains extremely large errors as described below.
第３図は変調信号周波数が800MHzで5Kmの単
一モード光フアイバを通した場合の温度変化によ
る検出位相差の変化を測定した実験結果である。
同図から明らかなように、１〔℃〕の温度変化に
対する位相変化Δθは約190度であるので、光フア
イバの周囲温度が１〔℃〕変化した場合の単位長
さ当りの群遅延時間の変化Δτ0は(1)、(2)式から次
のように求まる。 Figure 3 shows the experimental results of measuring the change in detected phase difference due to temperature change when the modulation signal frequency is 800 MHz and is passed through a 5 km single mode optical fiber.
As is clear from the figure, the phase change Δθ for a temperature change of 1 [°C] is approximately 190 degrees, so the group delay time per unit length when the ambient temperature of the optical fiber changes by 1 [°C] is approximately 190 degrees. The change Δτ 0 is determined from equations (1) and (2) as follows.
Δτ0＝Δtk／Ｌ＝Δθ／ｆ×360×1012／Ｌ
＝190／８×108×360×1012／５≒130〔ｐ−sec／Km〕
すなわち、群遅延時間の変化Δτ0（130〔ｐ−
sec／Km〕）は、光フアイバの伸びによる測定誤
差である。通常、1.3μｍ帯における群遅延特性の
精度が約１〔ｐ−sec／Km〕以内に要求されてい
ることから考えると、従来の測定方法では高精度
の測定が不可能であることがわかる。また、光フ
アイバの伸びは外部温度変化ΔTにほぼ比例する
ことから群遅延時間の誤差Δτは約Δτ0×ΔT〔ｐ−
sec／Km〕となり、温度変化が大きければさら
に大きな誤差を含むこととなる欠点がある。 Δτ 0 =Δt k /L=Δθ/f×360×10 12 /L
=190/8× 108 ×360× 1012 /5≒130[p-sec/Km] In other words, the change in group delay time Δτ 0 (130[p-sec/Km]
sec/Km]) is the measurement error due to the elongation of the optical fiber. Considering that the accuracy of group delay characteristics in the 1.3 μm band is normally required to be within about 1 [p-sec/Km], it is clear that high-precision measurement is not possible using conventional measurement methods. Furthermore, since the elongation of the optical fiber is approximately proportional to the external temperature change ΔT, the error Δτ in the group delay time is approximately Δτ 0 ×ΔT [p-
sec/Km], and has the disadvantage that it contains even larger errors if the temperature change is large.
本発明は、上述した従来技術の欠点を解決する
ためになされたもので、温度変化に伴つて生じる
光フアイバの伸びによる測定誤差を大幅に軽減
し、高精度の測定を可能とする光フアイバの分散
特性測定方法を提供することを目的とするもので
ある。 The present invention was made in order to solve the above-mentioned drawbacks of the prior art, and it is an optical fiber that significantly reduces measurement errors caused by the elongation of the optical fiber caused by temperature changes and enables high-precision measurement. The purpose of this invention is to provide a method for measuring dispersion characteristics.
以下本発明を詳細に説明する。 The present invention will be explained in detail below.
本発明による光フアイバの分散特性測定方法の
原理について説明する。本発明は、波長λcなる基
準光信号VRと任意の波長λk（ｋ＝１，２，…ｍ）
なる測定光信号Vnをそれぞれ正弦波で変調し、
被測定媒体である長さＬ〔Km〕なる光フアイバ
に同時に通光して、受信側では基準光信号VRと
測定光信号Vnにより伝達された変調波（正弦波）
を取り出し、その相対的な位相差Δθkを検出し測
定するものである。すなわち、基準光信号VRの
波長λcを固定し、測定光信号Vnの波長λkを所望
の波長λk（ｋ＝１，２，…ｍ）に変えて基準光信
号VRとの相対的な位相差Δθk（ｋ＝１，２，…ｍ）
を各々測定して、前記(1)、(2)式から相対的な遅延
特性Δτkを計算し、dτk／dλを求めれば所望の分
散特性が得られる。 The principle of the method for measuring dispersion characteristics of an optical fiber according to the present invention will be explained. The present invention uses a reference optical signal V R of wavelength λ c and an arbitrary wavelength λ k (k=1, 2,...m).
Each measurement optical signal V n is modulated with a sine wave,
The light is simultaneously transmitted through an optical fiber having a length of L [Km], which is the medium to be measured, and on the receiving side, a modulated wave (sine wave) transmitted by the reference optical signal V R and the measurement optical signal V n is transmitted.
is extracted and its relative phase difference Δθ k is detected and measured. That is, the wavelength λ c of the reference optical signal V R is fixed, the wavelength λ k of the measurement optical signal V n is changed to a desired wavelength λ k (k=1, 2,...m), and the wavelength λ c of the reference optical signal V R is changed to a desired wavelength λ k (k=1, 2,...m). Relative phase difference Δθ k (k=1, 2,...m)
The desired dispersion characteristics can be obtained by measuring the respective values, calculating the relative delay characteristics Δτ k from equations (1) and (2), and finding dτ k /dλ.
本発明の特徴は、波長λcが固定の基準光信号
VRと波長が可変の測定光信号Vnとを同一の被測
定媒体である光フアイバを同時に通光させること
によつて、光フアイバの伸びによる測定誤差を大
幅に改善したものである。 The feature of the present invention is that a reference optical signal with a fixed wavelength λ c
By simultaneously transmitting V R and the measurement optical signal V n of variable wavelength through the same optical fiber, which is the medium to be measured, measurement errors caused by the elongation of the optical fiber are greatly improved.
次に、従来技術と比較しどの程度、光フアイバ
の伸びによる測定誤差が改善されるかを説明す
る。例えば、変調波周波数を800〔ＭHz〕、光フ
アイバの長さＬを５〔Km〕、１〔℃〕当りの位相
変化Δθを約190度（第３図の実験結果より）とす
れば、温度変化１〔℃〕当りの光フアイバの伸び
係数Ｗは
Ｗ＝１／×Δθ／360×ｃ／ｎ×１／Ｌ
＝１／800×106×190／360×３×108／1.5
×１／５×103≒2.6×10-5（ｐ−sec／Km）…(3)
となる。ここで、ｃは真空中での光速（３×
108m／ｓ）、ｎは光フアイバの群屈折率（ｎ≒
1.5）である。 Next, it will be explained how much the measurement error due to the elongation of the optical fiber is improved compared to the conventional technology. For example, if the modulating wave frequency is 800 [MHz], the length L of the optical fiber is 5 [Km], and the phase change Δθ per 1 [℃] is approximately 190 degrees (according to the experimental results shown in Figure 3), then the temperature The elongation coefficient W of the optical fiber per change 1 [℃] is W = 1/×Δθ/360×c/n×1/L =1/800×10 6 ×190/360×3×10 8 /1.5
×1/5×10 3 ≒2.6×10 -5 (p-sec/Km)…(3). Here, c is the speed of light in vacuum (3×
10 8 m/s), n is the group refractive index of the optical fiber (n≒
1.5).
また、基準光信号VRの波長λcを1.5〔μｍ〕、測
定光信号Vnの波長λkを1.3〔μｍ〕とすれば、単
一モード光フアイバを伝搬する場合の基準光信号
VRと測定光信号Vnとの群遅延時間差Δτzは、Δτz
１×103〔ｐ−sec／Km〕である。従つて、温
度変化ΔTがあつた場合における光フアイバの伸
びΔL〔Km〕（ここでΔL＝Ｗ＝ΔT×Ｌ）での群
遅延時間差ΔτLは
ΔτL＝Δτz×ΔL …(4)
となる。 Furthermore, if the wavelength λ c of the reference optical signal V R is 1.5 [μm] and the wavelength λ k of the measurement optical signal V n is 1.3 [μm], then the reference optical signal when propagating through a single mode optical fiber
The group delay time difference Δτ z between V R and the measurement optical signal V n is Δτ z
It is 1×10 3 [p-sec/Km]. Therefore, when there is a temperature change ΔT, the group delay time difference Δτ L at the optical fiber elongation ΔL [Km] (where ΔL=W=ΔT×L) is Δτ L = Δτ z ×ΔL …(4) Become.
よつて、単位長さ当りの群遅延時間差ΔτLpは
ΔτLp＝Δτz×ΔL×１／Ｌ
＝１×103×2.6×10-5×ΔT＝2.6×10-2×
ΔT 〔ｐ−sec／Km〕…(5)
となる。 Therefore, the group delay time difference Δτ Lp per unit length is Δτ Lp = Δτ z ×ΔL×1/L = 1×10 3 ×2.6×10 -5 ×ΔT=2.6×10 -2 ×
ΔT [p-sec/Km]...(5)
すなわち、従来技術では温度変化１〔℃〕当り
の群遅延時間誤差Δτ0は約130〔ｐ−sec／Km〕で
あるのに対し、本発明では2.6×10-2〔ｐ−sec／
Km〕となり、約４桁（104）の誤差が改善され
る。 That is, in the conventional technology, the group delay time error Δτ 0 per 1 [°C] of temperature change is approximately 130 [p-sec/Km], whereas in the present invention, the group delay time error Δτ 0 is 2.6×10 -2 [p-sec/Km].
Km], and the error is improved by about 4 orders of magnitude (10 4 ).
以上のように、本発明では温度変化による光フ
アイバの伸びが生じても測定誤差を極めて小さく
出来るので、外部温度に影響されることなく高精
度の分散特性測定が可能となる。 As described above, according to the present invention, even if the optical fiber stretches due to temperature change, the measurement error can be made extremely small, so that highly accurate dispersion characteristic measurement is possible without being affected by external temperature.
次に、本発明による分散特性測定装置について
説明する。第４図は本発明を実施する場合の装置
例である。第４図において、９は固定波長光源、
１０は合波器、１１は分波器である。又、第５図
に合波器、分波器の特性を示す。第５図に示すよ
うに、合波器１０と分波器１１の透過波長帯域特
性を、λkの光が透過する所望の分散測定波長帯域
Ａと基準波長λcの光が透過する帯域Ｂが得られる
ようにα12とα13に設定する。変調が施された可変
波長光源２と固定波長光源９からそれぞれ出射す
る波長λkとλcの二つの被変調光信号を合波器１０
を介して同時に被測定光フアイバ５に通光する。
光フアイバ５からの二波の出射光を分波器１１で
分離し、それぞれ光電変換器６，７で電気信号に
変換する。位相比較器８により波長λc，λkの二波
の被変調光信号にそれぞれ含まれていた二つの変
調信号の位相差を検出することにより、種々の波
長λkの光の基準波長λcの光に対する相対群遅延時
間Δτk＝τk−τcを求め、第２図のａに示す群遅延
時間τと同様にして、Δτの特性を描き、ｄ
（Δτ）／dλを求めることにより光分散特性を得
る。 Next, a dispersion characteristic measuring device according to the present invention will be explained. FIG. 4 shows an example of an apparatus for implementing the present invention. In FIG. 4, 9 is a fixed wavelength light source;
10 is a multiplexer, and 11 is a demultiplexer. Furthermore, Fig. 5 shows the characteristics of the multiplexer and the demultiplexer. As shown in FIG. 5, the transmission wavelength band characteristics of the multiplexer 10 and the demultiplexer 11 are divided into a desired dispersion measurement wavelength band A where light with wavelength λ k is transmitted and a band B where light with reference wavelength λ c is transmitted. Set α 12 and α 13 so that . A multiplexer 10 combines two modulated optical signals with wavelengths λ k and λ c emitted from the modulated tunable wavelength light source 2 and fixed wavelength light source 9, respectively.
At the same time, the light passes through the optical fiber 5 to be measured.
Two waves of light emitted from the optical fiber 5 are separated by a demultiplexer 11 and converted into electrical signals by photoelectric converters 6 and 7, respectively. The phase comparator 8 detects the phase difference between the two modulated signals included in the two modulated optical signals with wavelengths λ c and λ k , thereby determining the reference wavelength λ c of light with various wavelengths λ k. Find the relative group delay time Δτ k =τ k −τ c for the light of
Optical dispersion characteristics are obtained by determining (Δτ)/dλ.
以上説明したように、本発明によれば、位相シ
フト法による光フアイバの分散測定において、所
望の測定波長帯域の種々の波長λk（ｋ＝１…ｎ）
と、基準となる波長λcの二光波の光フアイバでの
群遅延時間を同時に測定し、波長λkの光波の波長
λcの光波に対する相対群遅延時間を測定すること
により、被測定光フアイバの温度による伸びに起
因する測定誤差を大幅に軽減することができる。
よつて、高精度の分散特性の測定が可能となり、
本発明の効果は多大である。 As explained above, according to the present invention, in optical fiber dispersion measurement using the phase shift method, various wavelengths λ k (k=1...n) in a desired measurement wavelength band are used.
By simultaneously measuring the group delay times in the optical fiber of two light waves with the reference wavelength λ c and the reference wavelength λ c, and measuring the relative group delay time of the light wave with the wavelength λ k with respect to the light wave with the wavelength λ c , the optical fiber to be measured is Measurement errors caused by temperature-induced elongation can be significantly reduced.
Therefore, it is possible to measure dispersion characteristics with high precision,
The effects of the present invention are significant.
第１図は従来の位相シフト法による分散特性測
定の構成例を示すブロツク図、第２図は群遅延時
間及び光分散特性例を示す特性図、第３図は温度
変化による群遅延時間の変化を示す特性図、第４
図は本発明の実施例を示すブロツク図、第５図は
本発明に用いる合波器と分波器の特性例を示す特
性図、である。
１……変調信号発生器、２……可変波長光源、
３……波長計、４……光分岐器、５……被測定光
フアイバ、６，７……光電変換器、８……位相比
較器、９……固定波長光源、１０……合波器、１
１……分波器。
Figure 1 is a block diagram showing a configuration example of dispersion characteristic measurement using the conventional phase shift method, Figure 2 is a characteristic diagram showing an example of group delay time and optical dispersion characteristics, and Figure 3 is a change in group delay time due to temperature change. Characteristic diagram showing 4th
The figure is a block diagram showing an embodiment of the present invention, and FIG. 5 is a characteristic diagram showing an example of the characteristics of a multiplexer and a demultiplexer used in the present invention. 1...Modulation signal generator, 2...Variable wavelength light source,
3... Wavemeter, 4... Optical splitter, 5... Optical fiber to be measured, 6, 7... Photoelectric converter, 8... Phase comparator, 9... Fixed wavelength light source, 10... Multiplexer ,1
1... Duplexer.
Claims (1)
特性測定方法において、波長λcなる基準光信号
VRと該基準光信号の光源と異なる他の光源から
とり出された任意の波長λk（ｋ＝１，２，…ｍ）
なる測定光信号Vnとを正弦波で変調した二光波
を合波して被測定光フアイバに同時に通光すると
ともに、該被測定光フアイバの出力端において該
基準光信号VRの位相を基準とし該測定光信号Vn
の波長λkを所望の波長帯域において順次変化させ
た時の前記基準光信号と前記測定光信号とにそれ
ぞれ含まれる前記正弦波の各位相を測定すること
によつて相対群遅延特性を求め、前記光フアイバ
の光分散特性を得ることを特徴とする光フアイバ
の分散特性測定方法。1 In a method for measuring the dispersion characteristics of an optical fiber using the modulated optical phase shift method, a reference optical signal with wavelength λ c is used.
V R and an arbitrary wavelength λ k (k=1, 2,...m) extracted from another light source different from the light source of the reference optical signal
The two optical waves obtained by modulating the measurement optical signal V n with a sine wave are combined and simultaneously passed through the optical fiber under test, and the phase of the reference optical signal V R is used as a reference at the output end of the optical fiber under test. Then, the measurement optical signal V n
Determining the relative group delay characteristic by measuring each phase of the sine wave included in the reference optical signal and the measurement optical signal when the wavelength λ k of is sequentially changed in a desired wavelength band, A method for measuring dispersion characteristics of an optical fiber, characterized in that the light dispersion characteristics of the optical fiber are obtained.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24527883A JPS60140136A (en) | 1983-12-28 | 1983-12-28 | Measurement of dispersing characteristics of optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24527883A JPS60140136A (en) | 1983-12-28 | 1983-12-28 | Measurement of dispersing characteristics of optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60140136A JPS60140136A (en) | 1985-07-25 |
| JPH0354292B2 true JPH0354292B2 (en) | 1991-08-19 |
Family
ID=17131295
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24527883A Granted JPS60140136A (en) | 1983-12-28 | 1983-12-28 | Measurement of dispersing characteristics of optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60140136A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2504850B2 (en) * | 1989-11-16 | 1996-06-05 | 株式会社ヤマダコーポレーション | Reciprocating pump |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4752125A (en) * | 1986-12-19 | 1988-06-21 | Siecor Corporation | Apparatus to measure fiber dispersion |
| JPH079386B2 (en) * | 1988-05-18 | 1995-02-01 | 国際電信電話株式会社 | Optical fiber dispersion characteristics measurement method |
| JP4493808B2 (en) * | 2000-07-10 | 2010-06-30 | 株式会社アドバンテスト | Optical characteristic measuring apparatus, method, and recording medium |
| JP2002122515A (en) * | 2000-10-13 | 2002-04-26 | Advantest Corp | Light characteristic measuring device, method and recording medium |
| JP2002365165A (en) * | 2001-06-08 | 2002-12-18 | Sumitomo Electric Ind Ltd | Wavelength dispersion measuring device and method |
| ES2245177B1 (en) * | 2003-05-20 | 2007-02-01 | Universitat Politecnica De Catalunya | METHOD FOR MEASURING THE SPECTRAL DELAY RESPONSE OF GROUP TO OPTICAL FREQUENCIES WITH OPTICAL CARRIER FIXED AND SWEEP IN RADIO FREQUENCY USING PHASE DETECTION AND POLARIZATION LEVEL CONTROL. |
| US7809271B2 (en) | 2007-05-23 | 2010-10-05 | Cisco Technology Inc. | End-to-end chromatic dispersion characterization of optically amplified link |
| CN106996861A (en) * | 2017-03-24 | 2017-08-01 | 电子科技大学 | A kind of fibre-optical dispersion measuring method based on dual wavelength mode locking pulse optical fiber laser |
-
1983
- 1983-12-28 JP JP24527883A patent/JPS60140136A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2504850B2 (en) * | 1989-11-16 | 1996-06-05 | 株式会社ヤマダコーポレーション | Reciprocating pump |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60140136A (en) | 1985-07-25 |
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