JPH0210890B2 - - Google Patents
Info
- Publication number
- JPH0210890B2 JPH0210890B2 JP57111359A JP11135982A JPH0210890B2 JP H0210890 B2 JPH0210890 B2 JP H0210890B2 JP 57111359 A JP57111359 A JP 57111359A JP 11135982 A JP11135982 A JP 11135982A JP H0210890 B2 JPH0210890 B2 JP H0210890B2
- Authority
- JP
- Japan
- Prior art keywords
- polarization
- optical fiber
- temperature
- measured
- light
- 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 - Lifetime
Links
- 239000013307 optical fiber Substances 0.000 claims description 28
- 230000010287 polarization Effects 0.000 claims description 26
- 238000009529 body temperature measurement Methods 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 13
- 238000005259 measurement Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 4
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000000691 measurement method Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 230000018199 S phase Effects 0.000 description 2
- 238000000605 extraction Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Temperature Or Quantity Of Heat (AREA)
Description
【発明の詳細な説明】
本発明は温度測定法に係り、特に、偏波面保存
光フアイバを感温素子とする温度測定法に関する
ものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature measurement method, and particularly to a temperature measurement method using a polarization preserving optical fiber as a temperature sensing element.
第１図はセナルモンの位相差測定法の説明図で
ある。偏光子１、偏波面保存光フアイバ２、λ/4
板３及び検光子４は一直線上に配置されており、
偏光子１を通つた偏光軸は横方向にLo方向とな
つているものとする。これに対して検光子４の偏
光軸を垂直方向とした時は観測者の目には光が感
じられないで暗くなつている。 FIG. 1 is an explanatory diagram of Senarmont's phase difference measurement method. Polarizer 1, polarization maintaining optical fiber 2, λ/4
The plate 3 and analyzer 4 are arranged in a straight line,
It is assumed that the polarization axis passing through the polarizer 1 is in the Lo direction in the lateral direction. On the other hand, when the polarization axis of the analyzer 4 is set in the vertical direction, the observer's eyes cannot perceive the light and the light becomes dark.
次に位相差量に測定する対称物である偏波面保
存光フアイバ２の偏波面を45゜の方向にして設置
する。これをRΔ45゜と書く。これを通過後の偏光
状態はフアースト軸方向が水平で楕円率角がΔ／
２である楕円偏光となつている。この光をその光
の波長の1/4の遅れを生じさせる1/4波長板３を通
過させると、方位角がΔ／２の直線偏光となる。
即ち、楕円偏光が1/4波長板３を通ることによつ
て直線偏光となつている。 Next, the polarization-maintaining optical fiber 2, which is the object to be measured for the amount of phase difference, is installed with its polarization plane oriented at 45°. This is written as RΔ45°. After passing through this, the polarization state is such that the first axis direction is horizontal and the ellipticity angle is Δ/
It is elliptically polarized light, which is 2. When this light passes through the 1/4 wavelength plate 3 which causes a delay of 1/4 of the wavelength of the light, it becomes linearly polarized light with an azimuth angle of Δ/2.
That is, the elliptically polarized light becomes linearly polarized light by passing through the quarter-wave plate 3.
このような直線偏光が検光子４を通ると明るく
観察されるが、その視野が暗くなるまで検光子４
を回転角θだけ回転させると1/4波長板３を通つ
た直線偏光の方向と直交し、次の関係が成立す
る。 When such linearly polarized light passes through the analyzer 4, it is observed brightly, but until the field of view becomes dark, the analyzer 4
When is rotated by the rotation angle θ, it becomes perpendicular to the direction of linearly polarized light passing through the quarter-wave plate 3, and the following relationship holds true.
Δ／２−θ＝π／２
即ち、Δ＝2θ＋πとなり、θを求めて位相差Δ
を知ることができる。 Δ/2-θ=π/2 In other words, Δ=2θ+π, find θ and calculate the phase difference Δ
You can know.
このような操作を偏波面保存光フアイバ２の温
度を変化させ、予め温度とΔとの関係を求めて置
けば、偏波面保存光フアイバ２を用いた温度測定
が可能となる筈である。しかし、従来はこのよう
な方法は行われていないし、それを示す公知例も
見当らない。 If such an operation is performed by changing the temperature of the polarization preserving optical fiber 2 and determining the relationship between the temperature and Δ in advance, temperature measurement using the polarization preserving optical fiber 2 should become possible. However, such a method has not been used in the past, and there are no known examples showing it.
本発明は、上記原理に基づいて新規な偏波面保
存光フアイバを用いた温度測定法を提供すること
を目的とし、その特徴とするところは、被測定雰
囲気に設置した偏波面保存光フアイバに偏向を導
入して偏向軸の回転状態をセナルモン補償法によ
つて検出し、予め測定した温度変化による偏向軸
の回転特性と比較することにある。 The present invention aims to provide a temperature measurement method using a novel polarization-maintaining optical fiber based on the above-mentioned principle. The purpose is to detect the rotational state of the deflection axis by the Senarmont compensation method and compare it with the rotational characteristics of the deflection axis due to temperature changes measured in advance.
第２図は本発明の一実施例である偏波面保存光
フアイバを用いた温度測定系のブロツク図であ
る。半導体レーザを用いた光源５から出射した単
色光は偏光子１で完全な直線偏向となり、偏波面
保存光フアイバ２のフアースト軸及びスロー軸に
対して45゜の方位に入射する。このようにするに
は、偏波面保存光フアイバ２の入射端を所定の方
位になるように回転し乍ら、フアースト軸とスロ
ー軸の光量が等しくなる所にセツトすればよい。 FIG. 2 is a block diagram of a temperature measurement system using a polarization maintaining optical fiber, which is an embodiment of the present invention. Monochromatic light emitted from a light source 5 using a semiconductor laser is completely linearly polarized by a polarizer 1 and is incident on a polarization preserving optical fiber 2 at an angle of 45 degrees with respect to the fast axis and slow axis. To do this, the input end of the polarization-preserving optical fiber 2 may be rotated to a predetermined orientation and set at a location where the amounts of light on the fast axis and the slow axis are equal.
偏波面保存光フアイバ２はその感温部６を被測
定雰囲気に設置する。感温部の長さをｌ（ｍ）、直
交偏波モード間のその波長での結合長をＬ（ｍ）
とすると、偏波面保存光フアイバ２内を伝播する
直交２軸成分の光の温度変化による位相差Δの変
化は次式で与えられる。 The temperature sensing portion 6 of the polarization preserving optical fiber 2 is installed in the atmosphere to be measured. The length of the temperature sensing part is l (m), and the coupling length at that wavelength between orthogonal polarization modes is L (m).
Then, the change in the phase difference Δ due to the temperature change of the orthogonal two-axis component light propagating in the polarization-maintaining optical fiber 2 is given by the following equation.
Δ＝Δβ（T1）・ｌ（T1）−Δβ（T2）・ｌ（T2）……
(1)
但し、T1、T2は変化した温度、Δβ（Ｔ）は温
度Ｔにおける直交偏波モードの伝播定数差であ
る。Δ=Δβ(T 1 )・l(T 1 )−Δβ(T 2 )・l(T 2 )...
(1) However, T 1 and T 2 are the changed temperatures, and Δβ(T) is the difference in propagation constant of the orthogonal polarization mode at the temperature T.
Δβ（Ｔ）＝2π／Ｌ（Ｔ） ……(2)
ここでＬ（Ｔ）は温度Ｔにおける結合長を示し
ている。 Δβ(T)=2π/L(T)...(2) Here, L(T) indicates the bond length at temperature T.
さて、楕円ジヤケツト型の偏波面保存光フアイ
バの結合長は
Ｌ（Ｔ）＝Ｋ（T0−Ｔ）＝δT ……(3)
但し、Ｋは定数、T0は異方性歪がない温度で、
およそ1500℃の確定した値である。 Now, the coupling length of an elliptical jacket-type polarization-maintaining optical fiber is L(T) = K(T 0 - T) = δT...(3) where K is a constant and T 0 is the temperature at which there is no anisotropic strain. in,
It is a fixed value of approximately 1500℃.
ΔT＝T1−T2 ……(4)
とすると、
Δ＝2πｌ（Ｔ）／Ｌ（Ｔ）−１＋（T0−Ｔ）ａ／T0−
Ｔ−ΔT
＝2πｌ（Ｔ）／Ｌ（Ｔ）１／δT−ΔT……(5)
何故ならば、ａ10-5、T0−Ｔ1.5×103 (5)
式は位相差（リターデーシヨン）が（δT−ΔT）
に逆比例することを意味している。 If ΔT=T 1 −T 2 ...(4), then Δ=2πl(T)/L(T)−1+(T 0 −T)a/T 0 −
T-ΔT = 2πl(T)/L(T)1/δT-ΔT...(5) Because a10 -5 , T 0 -T1.5×10 3 (5)
The formula is that the phase difference (retardation) is (δT−ΔT)
This means that it is inversely proportional to .
即ち、ΔTの温度差による偏波面保存光フアイ
バ２の長さの変化は測定精度には無関係で、結合
長の温度によるリターデーシヨンだけが関係する
ことになる。従つて、予め感温部６の温度と位相
差との関係を求めておけば、位相差を求めること
によつて感温部６の温度を知ることができる。 That is, the change in the length of the polarization-maintaining optical fiber 2 due to the temperature difference of ΔT has no bearing on measurement accuracy, and only the retardation of the coupling length due to temperature is relevant. Therefore, if the relationship between the temperature of the temperature sensing section 6 and the phase difference is determined in advance, the temperature of the temperature sensing section 6 can be determined by determining the phase difference.
尚、位相差（リターデーシヨン）の測定は次の
セナルモンの方法によつている。 Note that the phase difference (retardation) is measured by the following Senarmont method.
感温部６で変化して楕円化した伝送偏光は、1/
４波長板３によつて直線偏光に規制された検光子
４に入射する。検光子４を通つた直線偏光は光電
検知器７によつて検知されて光パワーメータ８で
その強さが検知される。即ち、光パワーメータ８
の指針が最小の光量を示すように検光子４を回転
させ、その回転角度から偏波面保存光フアイバ２
の感温部６の温度変化を知ることができる。 The transmitted polarized light that has changed and become elliptical in the temperature sensing part 6 is 1/
The light enters the analyzer 4, which is regulated to linearly polarized light by the four-wavelength plate 3. The linearly polarized light passing through the analyzer 4 is detected by a photoelectric detector 7, and its intensity is detected by an optical power meter 8. That is, the optical power meter 8
The analyzer 4 is rotated so that the pointer indicates the minimum amount of light, and the polarization preserving optical fiber 2 is determined from the rotation angle.
It is possible to know the temperature change of the temperature sensing section 6.
このような測定法は光フアイバと偏光を利用し
ているので電気的な雑音に妨害されることなく正
確な温度測定が可能である。又、被測定雰囲気に
偏波面保存光フアイバを布設すれば良いので狭い
場所の温度も測定できるし、その測定設備も簡便
である。 These measurement methods utilize fiber optics and polarized light, allowing accurate temperature measurements without interference from electrical noise. Furthermore, since it is sufficient to install a polarization preserving optical fiber in the atmosphere to be measured, the temperature can be measured in a narrow place, and the measurement equipment is simple.
尚、石英製の光フアイバを用いているので数百
度の広い温度範囲に亘つて測定できるという利点
をもつており、特に楕円ジヤケツト型の偏波面保
存光フアイバは偏光軸が明確で高精度に実施でき
る。 Furthermore, since it uses a quartz optical fiber, it has the advantage of being able to perform measurements over a wide temperature range of several hundred degrees.Especially, the elliptical jacket type polarization preserving optical fiber has a clear polarization axis and can be carried out with high precision. can.
本実施例の偏波面保存光フアイバを用いたセナ
ルモン法による温度測定法は、比較的簡単な設備
で電気的妨害を受けることなく正確に測定できる
という効果をもつている。 The temperature measurement method based on the Senarmont method using the polarization-preserving optical fiber of this embodiment has the advantage that accurate measurement can be performed with relatively simple equipment and without electrical interference.
本発明の類似の原理を利用した発明に、特公昭
48−13473号公報に開示されたものがあるが、こ
の発明では特殊な結晶を使用しなくてはならない
から、結晶への光の導入部、結晶からの光の導出
部が温度測定精度に影響を及ぼす欠点があり、測
定精度の向上が困難である。 For an invention utilizing a similar principle to the present invention,
There is a method disclosed in Japanese Patent No. 48-13473, but since this invention requires the use of a special crystal, the part where light enters the crystal and the part where light exits from the crystal affect temperature measurement accuracy. However, it is difficult to improve measurement accuracy.
これに対し、本発明では被測定雰囲気には光の
導入部、導出部は存在せず、正確な温度測定がで
きるものであり、又、測定精度を高めるために
は、必要に応じて偏波面保存光フアイバの長さを
長くすればよく、容易に測定精度を向上できるも
のである。 On the other hand, in the present invention, there is no light introduction part or light extraction part in the atmosphere to be measured, and accurate temperature measurement is possible. The measurement accuracy can be easily improved by simply increasing the length of the storage optical fiber.
本発明の偏波面保存光フアイバを用いた温度測
定法は数百度までの広い温度範囲に亘つて正確に
測定可能であるという効果が得られる。 The temperature measurement method using the polarization-maintaining optical fiber of the present invention has the advantage that accurate measurement can be performed over a wide temperature range up to several hundred degrees.
第１図はセナルモンの位相差測定法の説明図、
第２図は本発明の一実施例である偏波面保存光フ
アイバを用いた温度測定系のブロツク図である。
１：偏光子、２：偏波面保存光フアイバ、３：
１／４波長板、４：検光子、５：光源、６：感温部、
７：光電検知器、８：光パワーメータ。
Figure 1 is an explanatory diagram of Senarmont's phase difference measurement method.
FIG. 2 is a block diagram of a temperature measurement system using a polarization maintaining optical fiber, which is an embodiment of the present invention. 1: Polarizer, 2: Polarization maintaining optical fiber, 3:
1/4 wavelength plate, 4: Analyzer, 5: Light source, 6: Temperature sensing part,
7: Photoelectric detector, 8: Optical power meter.
Claims (1)
し、当該偏波面保存光フアイバの両端を被測定雰
囲気外へ取り出して偏光を導入し、偏光軸の回転
状態をセナルモン補償法によつて検出し、予め測
定した温度変化による上記偏光軸の回転特性と比
較することを特徴とする偏波面保存光フアイバを
用いた温度測定法。 ２ 上記偏波面保存光フアイバが、楕円ジヤケツ
ト型の光フアイバである特許請求の範囲第１項記
載の偏波面保存光フアイバを用いた温度測定法。[Scope of Claims] 1. A polarization preserving optical fiber is installed in the atmosphere to be measured, both ends of the polarization preserving optical fiber are taken out of the atmosphere to be measured, polarized light is introduced, and the rotational state of the polarization axis is determined by the Senarmont compensation method. 1. A temperature measurement method using a polarization-maintaining optical fiber, characterized in that the rotation characteristic of the polarization axis is detected by a temperature change measured in advance and compared with the rotation characteristic of the polarization axis caused by a temperature change measured in advance. 2. A temperature measurement method using a polarization maintaining optical fiber according to claim 1, wherein the polarization maintaining optical fiber is an elliptical jacket type optical fiber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57111359A JPS59634A (en) | 1982-06-28 | 1982-06-28 | Temperature measuring method using optical fiber preserving polarized wave surface |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57111359A JPS59634A (en) | 1982-06-28 | 1982-06-28 | Temperature measuring method using optical fiber preserving polarized wave surface |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59634A JPS59634A (en) | 1984-01-05 |
| JPH0210890B2 true JPH0210890B2 (en) | 1990-03-12 |
Family
ID=14559194
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57111359A Granted JPS59634A (en) | 1982-06-28 | 1982-06-28 | Temperature measuring method using optical fiber preserving polarized wave surface |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59634A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61270632A (en) * | 1985-05-25 | 1986-11-29 | Hitachi Cable Ltd | Optical fiber type measuring instrument for temperature distribution |
| EP0538072A3 (en) * | 1991-10-17 | 1993-08-04 | Canon Kabushiki Kaisha | Method and apparatus for detecting superconductor quench and method and apparatus for preventing superconductor quench |
| US6174081B1 (en) * | 1998-01-30 | 2001-01-16 | The United States Of America As Represented By The Secretary Of The Navy | Specular reflection optical bandgap thermometry |
| CN106500866A (en) * | 2016-09-08 | 2017-03-15 | 国家电网公司 | A kind of optic temperature sensor and temp measuring method |
-
1982
- 1982-06-28 JP JP57111359A patent/JPS59634A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59634A (en) | 1984-01-05 |
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