JPS5930032A - Optical fiber thermometer - Google Patents
Optical fiber thermometerInfo
- Publication number
- JPS5930032A JPS5930032A JP57140792A JP14079282A JPS5930032A JP S5930032 A JPS5930032 A JP S5930032A JP 57140792 A JP57140792 A JP 57140792A JP 14079282 A JP14079282 A JP 14079282A JP S5930032 A JPS5930032 A JP S5930032A
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- light
- temperature
- counter
- light intensity
- 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
- 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)
Abstract
Description
【発明の詳細な説明】
本発明は単一モードの複屈折性光ファイバを用いた温度
計に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermometer using a single mode birefringent optical fiber.
従来、光ファイバを用いた比較的高精度の温度計として
は、半導体や螢光体などの特殊な物質をセンサとして用
い光ファイバを単に光の伝達媒質の手段として利用した
ものが実用化されている。しかしながら、従来のこのよ
うな温度計は、センサと光ファイバの結合部の信頼性が
低いという問題があり、また、アナログ処理を行なって
いるので精度にも限度があった。Conventionally, relatively high-precision thermometers using optical fibers have been put into practical use, using special materials such as semiconductors or fluorescent materials as sensors, and using optical fibers simply as a light transmission medium. There is. However, such conventional thermometers have a problem in that the reliability of the connection between the sensor and the optical fiber is low, and since analog processing is performed, there is a limit to accuracy.
本発明は従来のこのような問題点を解消するためになさ
れたものであり、その目的とするところは、光フアイバ
自身をセンサとして用いること罠よりセンサと光ファイ
バの結合部をなくすとともに、ディジタル処理によって
容易高精度かつ高安定性が得られるような光フアイバ温
度計を提供することにある。The present invention has been made to solve these conventional problems, and its purpose is to eliminate the coupling part between the sensor and the optical fiber rather than using the optical fiber itself as a sensor, and also to eliminate the coupling part between the sensor and the optical fiber. An object of the present invention is to provide an optical fiber thermometer that can easily obtain high accuracy and high stability through processing.
本発明はこのような目的を達成するために、複屈折性光
ファイバを用い、温度による複屈折性の大きさの変化に
もとすく信号の位相をディジタル的姉検出するようにし
たものである。In order to achieve such an object, the present invention uses a birefringent optical fiber and digitally detects the phase of a signal even when the magnitude of birefringence changes due to temperature. .
以下、本発明を実施例を用いて詳細に説明する。Hereinafter, the present invention will be explained in detail using Examples.
第１図は本発明に係る光フアイバ温度計の一実施例の構
成図である。図において、半導体レーザや発光ダイオー
ドなどからなる光源１から出た光は、直線偏光子２で直
線偏光された後、集光レンズを用いるなど通常知られた
方法によって複屈折性光ファイバ３の一端に注入される
。ここで、複屈折性光ファイバ３の偏光軸は、入射光の
偏光方向と４５°の方位に設定されている。複屈折性光
ファイバ３の中を伝播し他端から出た光は、光ビーム分
割器４によって２分される。２分された光ビームの一方
のビームは、４分の１波長板５を通って９０°の位相差
を生じた後、偏光子６を通過して光検出器７で受信され
、光強度工、の電気信号となって出力される。FIG. 1 is a configuration diagram of an embodiment of an optical fiber thermometer according to the present invention. In the figure, light emitted from a light source 1 consisting of a semiconductor laser, a light emitting diode, etc. is linearly polarized by a linear polarizer 2, and then connected to one end of a birefringent optical fiber 3 by a commonly known method such as using a condenser lens. is injected into. Here, the polarization axis of the birefringent optical fiber 3 is set at an angle of 45° with respect to the polarization direction of the incident light. The light propagating through the birefringent optical fiber 3 and exiting from the other end is split into two by a light beam splitter 4. One of the two divided light beams passes through a quarter-wave plate 5 to generate a 90° phase difference, passes through a polarizer 6, is received by a photodetector 7, and is processed by a light intensity filter. , is output as an electrical signal.
一方、光ビーム分割器４で２分された他方のビームは、
４分の１波長板を通らず偏光子８のみ通過して光検出器
９で受信され、光強度１．の電気信号となって出力され
る。On the other hand, the other beam split into two by the optical beam splitter 4 is
It passes only through the polarizer 8 without passing through the quarter-wave plate and is received by the photodetector 9, and the light intensity is 1. is output as an electrical signal.
ここで、光強度Ｉ、、１．は次式のようになる。Here, the light intensity I,,1. is as follows.
ＩＩ ＝ Ｉｏ （１＋ ｃｏｓΔ）
Ｉｔ＝ Ｉａ Ｃ１＋ｓｉｎ△）
ただし、ＩＯは定数、Δは複屈折性光ファイバ３の複屈
折の大きさである。このΔはよく知られているように温
度とともに変化する量である。そして、光強度Ｉ、、Ｉ
−は温度とともに第２図に示すように変化する。光強度
１．と１、は△に関して９０°の位相差を有する。II = Io (1+cosΔ) It=Ia C1+sinΔ) However, IO is a constant, and Δ is the magnitude of birefringence of the birefringent optical fiber 3. This Δ is a quantity that changes with temperature, as is well known. And the light intensity I,,I
- changes with temperature as shown in FIG. Light intensity 1. and 1 have a phase difference of 90° with respect to Δ.
第１図において、１０はカウンタであり、Ｉ１とＩ２を
入力して△の符号を含めた大きさをディジタルカウント
する。このとき、カウント値は例えば第３図に示すよう
に、光ファイバ３の温度と一次比例する。In FIG. 1, 10 is a counter, which inputs I1 and I2 and digitally counts the magnitude including the sign of Δ. At this time, the count value is linearly proportional to the temperature of the optical fiber 3, for example, as shown in FIG.
なお、△は光ファイバ３が機械的振動を受けることによ
っても変化するが、これから生じる信号は振動的であり
、カウンタ１ｏにはカウントされない。Note that Δ also changes when the optical fiber 3 is subjected to mechanical vibration, but the signal generated from this is vibrational and is not counted by the counter 1o.
このように、・本発明姉係る光フアイバ温度計によると
、光ファイバが自身でセンサとして作用するために従来
のようなセンサと光ファイバの結合部の信頼性低下とい
う問題は全くなくなり、しかも、温度をディジタル処理
で計測できるので従来のアナログ式に比して容易に高精
度かつ高安定性を得ることができる。As described above, according to the optical fiber thermometer according to the present invention, since the optical fiber itself acts as a sensor, there is no problem of decreased reliability of the coupling part between the sensor and the optical fiber as in the past. Since temperature can be measured digitally, higher accuracy and stability can be easily obtained compared to conventional analog methods.
また、センサ構造が簡単になるばかりでなく、機械的振
動如よる測定誤差もなくなる。Moreover, not only the sensor structure is simplified, but also measurement errors due to mechanical vibrations are eliminated.
また、センサが可とう性があり高絶縁性の光ファイバか
らなっているために、高電圧機器や動力機関の内部など
、通常の電気的測定が困難な環境においても遠隔計測が
可能となり、温度の測定が容易にできるようＫなる。Additionally, since the sensor is made of flexible, highly insulated optical fiber, it is possible to remotely measure temperatures in environments where normal electrical measurements are difficult, such as inside high-voltage equipment or power engines. K so that it can be easily measured.
第１図は本発明に係る光フアイバ温度計の一実施例の構
成図、第２図は温度と光強度の関係を示すグラフ、第３
図は温度とカウント値の関係を示すグラフである。
１・・・・・・・・・・・・光源
２・・・・・・・・・・・・直線偏光子３・・・・・・
・・・・・・複屈折性光ファイバ４・・・・・・・・・
・・・光ビーム分割器５・・・・・・・・・・・・４分
の１波長板６．８・・・・・・偏光子
７．９・・・・・・光検出器
１０・・・・・・・・・カウンタ
特許出願人 芳 野 俊 彦
Ｎ’ ｉ３ｄ
シＷｔ、汽（Ｃ）Fig. 1 is a configuration diagram of an embodiment of an optical fiber thermometer according to the present invention, Fig. 2 is a graph showing the relationship between temperature and light intensity, and Fig. 3 is a graph showing the relationship between temperature and light intensity.
The figure is a graph showing the relationship between temperature and count value. 1......Light source 2...Linear polarizer 3...
...Birefringent optical fiber 4...
...Light beam splitter 5 ...... Quarter wavelength plate 6.8 ... Polarizer 7.9 ... Photodetector 10・・・・・・・・・Counter patent applicant Toshihiko Yoshino N' i3d SiWT, Steam (C)
Claims (1)
入力させる光入力手段と、前記光ファイバの他端からの
出力光を分割する光学的千竣と、分割した光の直交偏光
間に９０゜の位相差を生じさせる光学的手段と、前記直
交偏光間に干渉を生じさせる光学的手段と、それぞれの
光強度を検出する検出手段と、この検出手段から出力さ
れる電気信号の絶対位祖をディジタル検出する手段とを
備えた光フアイバ温度計。A birefringent optical fiber, a light input means for inputting light from one end of the optical fiber, an optical end for splitting the output light from the other end of the optical fiber, and a 90° angle between the orthogonal polarizations of the split light. optical means for producing a phase difference of 100°, optical means for producing interference between the orthogonal polarized lights, detection means for detecting the respective light intensities, and absolute position resolution of the electrical signal output from the detection means. A fiber optic thermometer with means for digitally detecting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57140792A JPS5930032A (en) | 1982-08-13 | 1982-08-13 | Optical fiber thermometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57140792A JPS5930032A (en) | 1982-08-13 | 1982-08-13 | Optical fiber thermometer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5930032A true JPS5930032A (en) | 1984-02-17 |
Family
ID=15276843
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57140792A Pending JPS5930032A (en) | 1982-08-13 | 1982-08-13 | Optical fiber thermometer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5930032A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009003449A1 (en) * | 2007-06-29 | 2009-01-08 | Trumpf Laser- Und Systemtechnik Gmbh | Monitoring the temperature of an optical element |
| US7836773B2 (en) * | 2006-10-18 | 2010-11-23 | Fujikura Ltd. | Optical fiber thermometer and temperature-compensated optical fiber sensor |
-
1982
- 1982-08-13 JP JP57140792A patent/JPS5930032A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7836773B2 (en) * | 2006-10-18 | 2010-11-23 | Fujikura Ltd. | Optical fiber thermometer and temperature-compensated optical fiber sensor |
| WO2009003449A1 (en) * | 2007-06-29 | 2009-01-08 | Trumpf Laser- Und Systemtechnik Gmbh | Monitoring the temperature of an optical element |
| US8434938B2 (en) | 2007-06-29 | 2013-05-07 | Trumpf Laser-Und Systemtechnik Gmbh | Monitoring a temperature and/or temperature related parameters of an optical element |
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