JPS6338655B2 - - Google Patents
Info
- Publication number
- JPS6338655B2 JPS6338655B2 JP12715779A JP12715779A JPS6338655B2 JP S6338655 B2 JPS6338655 B2 JP S6338655B2 JP 12715779 A JP12715779 A JP 12715779A JP 12715779 A JP12715779 A JP 12715779A JP S6338655 B2 JPS6338655 B2 JP S6338655B2
- Authority
- JP
- Japan
- Prior art keywords
- wavelength
- fiber
- light
- measuring
- phase difference
- 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
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
-
- 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
- G01M11/338—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 by measuring dispersion other than PMD, e.g. chromatic dispersion
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Optics & Photonics (AREA)
- Analytical Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Dispersion Chemistry (AREA)
- Testing Of Optical Devices Or Fibers (AREA)
Description
【発明の詳細な説明】
本発明は光フアイバの材料分散特性の測定方法
に関するものである。光フアイバを構成するガラ
ス材料の屈折率は波長により異なるため、使用す
る光の波長によつてフアイバのベースバンド周波
数特性が異なる。こうした光フアイバの材料分散
特性を測定することはフアイバの構造設計を行な
う際に重要となる。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring material dispersion properties of optical fibers. Since the refractive index of the glass material that makes up the optical fiber differs depending on the wavelength, the baseband frequency characteristics of the fiber differ depending on the wavelength of the light used. Measuring the material dispersion characteristics of such optical fibers is important when designing the structure of the fiber.
本発明は光フアイバの分散のうち、材料分散の
効果だけを分離測定する高精度な測定方法を示す
ものである。以下、図を用いて本発明の詳細を説
明する。図において、１は波長可変光源、２は外
部変調器、３は電気信号発生器、４は分波器、５
および６は長さを異にする同じ光フアイバ、７お
よび８は検波器、９は位相差測定器を示す。 The present invention provides a highly accurate measuring method for separately measuring only the effect of material dispersion among the dispersion of optical fibers. Hereinafter, details of the present invention will be explained using figures. In the figure, 1 is a wavelength tunable light source, 2 is an external modulator, 3 is an electric signal generator, 4 is a demultiplexer, and 5 is a wavelength tunable light source.
and 6 are the same optical fibers of different lengths, 7 and 8 are detectors, and 9 is a phase difference measuring device.
さて、１よりの光は外部変調器３を通過する際
に電気信号発生器３よりの高周波信号によつて振
幅変調される。この変調された光はハーフ・ミラ
ーなどの分波器４によつて二つに分岐され、一方
はフアイバ５に、他方はフアイバ６に入射され、
それぞれ検波器７および８によつて電気信号に変
換される。これらの電気信号はベクトルボルトメ
ータなどの位相差測定器９によつて位相差が測定
される。 Now, when the light from 1 passes through the external modulator 3, it is amplitude-modulated by a high frequency signal from the electric signal generator 3. This modulated light is split into two by a splitter 4 such as a half mirror, one of which is incident on the fiber 5 and the other is incident on the fiber 6.
They are converted into electrical signals by detectors 7 and 8, respectively. The phase difference of these electrical signals is measured by a phase difference measuring device 9 such as a vector voltmeter.
次に、１の光源の波長を少し変化させ、再び位
相差を測定する。以下、順次１の波長を変えるこ
とによつて、その波長に対する位相変化量が測定
される。 Next, the wavelength of the first light source is slightly changed and the phase difference is measured again. Thereafter, by sequentially changing the first wavelength, the amount of phase change for that wavelength is measured.
いま、電気信号発生器の変調周波数を（Hz）、
フアイバ５および６の長さをそれぞれL1，L2と
し、波長λiでの光フアイバの群屈折率をＮ（λi）
とする。 Now, the modulation frequency of the electrical signal generator is (Hz),
Let the lengths of fibers 5 and 6 be L 1 and L 2 , respectively, and the group refractive index of the optical fiber at wavelength λi be N(λi).
shall be.
ただし、
Ｎ（λ）＝ｎ（λ）−λdn（λ）／dλ (1)
であり、ｎは屈折率、λは光の波長である。さ
て、位相差測定器９の位相量は、
Qi＝L1−L2／λｇ×360゜ (2)
となる。ここに、
λｇ＝Ｃ／Ｎ（λi） (3)
である。ここで、光の波長をλiからλjに変化させ
ると、相対位相量は、
θ1−θ2＝（L1−L2）・360゜／Ｃ
｛Ｎ（λi）−Ｎ（λj）｝ (4)
となる。式(4)において、（L1−L2），，Ｃは既
知であるため、波長λiを固定してλjを順次変化さ
せた場合の位相変化量より群屈折率の変化量｛Ｎ
（λi）−Ｎ（λj）｝を知ることができる。例えば、λ
i
＝0.85μm，λj＝1.3μm，L1−L2＝1000ｍとする
と、代表的な光フアイバの場合、＝100MHzで、
約56゜の位相量が測定される。こうした測定結果
をもとに、測定波長に対応する各測定点を結んだ
曲線の変化率が材料分散となるわけである。 However, N(λ)=n(λ)−λdn(λ)/dλ (1) where n is the refractive index and λ is the wavelength of light. Now, the phase amount of the phase difference measuring device 9 is Qi=L 1 −L 2 /λg×360° (2). Here, λg=C/N(λi) (3). Here, when the wavelength of light is changed from λi to λj, the relative phase amount is θ 1 −θ 2 = (L 1 − L 2 )・360°/C {N(λi)−N(λj)} ( 4) becomes. In Equation (4), (L 1 −L 2 ), , C is known, so the amount of change in the group refractive index {N
(λi)−N(λj)}. For example, λ
i
= 0.85μm, λj = 1.3μm, L 1 −L 2 = 1000m, then for a typical optical fiber, at = 100MHz,
A phase amount of approximately 56° is measured. Based on these measurement results, the rate of change of the curve connecting each measurement point corresponding to the measurement wavelength is the material dispersion.
以上示したように、本発明は単一の正弦波で振
幅変調された光を二分割して、それぞれの光を長
さの異なるフアイバに入射し、フアイバ伝搬後の
検波信号の位相差を、光の波長を変えて測定する
ことを特徴とする。本発明によれば、従来のパル
ス遅延時間差測定におけるようなフアイバ伝搬後
のパルス波形の歪の影響をなくすことができ、高
精度な測定が可能である。 As described above, the present invention splits light amplitude-modulated with a single sine wave into two, inputs each light into fibers of different lengths, and calculates the phase difference of the detected signal after propagation through the fiber. It is characterized by measuring by changing the wavelength of light. According to the present invention, it is possible to eliminate the influence of distortion of the pulse waveform after fiber propagation as in conventional pulse delay time difference measurement, and highly accurate measurement is possible.
図は本発明の測定方法をあらわすブロツク図を
示す。
図中、１は波長可変光源、２は外部変調器、３
は電気信号発生器、４は分波器、５および６は光
フアイバ、７および８は検波器、９は位相差測定
器を示す。
The figure shows a block diagram representing the measuring method of the present invention. In the figure, 1 is a wavelength tunable light source, 2 is an external modulator, and 3
4 is an electric signal generator, 4 is a branching filter, 5 and 6 are optical fibers, 7 and 8 are wave detectors, and 9 is a phase difference measuring device.
Claims (1)
岐し、これらの光を長さの異なる二個のフアイバ
に入射し、該フアイバを伝搬した光の検波信号の
位相差を、前記の光の波長を順次変えながら測定
し、各波長に対する各測定値の変化率を求めるこ
とを特徴とするフアイバの材料分散特性測定方
法。1. Split the light that has been amplitude modulated at a certain frequency into two, enter these lights into two fibers with different lengths, and calculate the phase difference of the detected signal of the light that has propagated through the fibers. 1. A method for measuring material dispersion characteristics of a fiber, the method comprising measuring the material dispersion characteristics of a fiber while sequentially changing the wavelength, and determining the rate of change of each measured value for each wavelength.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12715779A JPS5651636A (en) | 1979-10-01 | 1979-10-01 | Measuring method for material dispersion characteristic of fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12715779A JPS5651636A (en) | 1979-10-01 | 1979-10-01 | Measuring method for material dispersion characteristic of fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5651636A JPS5651636A (en) | 1981-05-09 |
| JPS6338655B2 true JPS6338655B2 (en) | 1988-08-01 |
Family
ID=14953039
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12715779A Granted JPS5651636A (en) | 1979-10-01 | 1979-10-01 | Measuring method for material dispersion characteristic of fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5651636A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6073333A (en) * | 1983-09-30 | 1985-04-25 | Sumitomo Electric Ind Ltd | Optical fiber dispersion measuring method |
| JPS6352034A (en) * | 1986-08-21 | 1988-03-05 | Nippon Telegr & Teleph Corp <Ntt> | Method and device for measuring single mode optical fiber |
| FR2689632B1 (en) * | 1992-04-02 | 1997-09-19 | Thomson Csf | FIBER OPTICAL STRESS DETECTOR. |
| JP3388227B2 (en) * | 1999-11-05 | 2003-03-17 | 独立行政法人通信総合研究所 | Optical dispersion measuring apparatus and measuring method using the same |
| WO2011042911A2 (en) * | 2009-10-09 | 2011-04-14 | Hitesh Mehta | Method and apparatus for demonstration and determination of material dispersion in optical fiber |
-
1979
- 1979-10-01 JP JP12715779A patent/JPS5651636A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5651636A (en) | 1981-05-09 |
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