JPH0376693B2 - - Google Patents
Info
- Publication number
- JPH0376693B2 JPH0376693B2 JP58101495A JP10149583A JPH0376693B2 JP H0376693 B2 JPH0376693 B2 JP H0376693B2 JP 58101495 A JP58101495 A JP 58101495A JP 10149583 A JP10149583 A JP 10149583A JP H0376693 B2 JPH0376693 B2 JP H0376693B2
- Authority
- JP
- Japan
- Prior art keywords
- optical
- light
- optical fiber
- light receiving
- waveguides
- 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
- 230000003287 optical effect Effects 0.000 claims description 78
- 239000013307 optical fiber Substances 0.000 claims description 24
- 230000008878 coupling Effects 0.000 claims description 9
- 238000010168 coupling process Methods 0.000 claims description 9
- 238000005859 coupling reaction Methods 0.000 claims description 9
- 230000001427 coherent effect Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 230000005855 radiation Effects 0.000 description 2
- 229910013641 LiNbO 3 Inorganic materials 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35303—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using a reference fibre, e.g. interferometric devices
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Temperature Or Quantity Of Heat (AREA)
- Measuring Magnetic Variables (AREA)
- Spectrometry And Color Measurement (AREA)
- Optical Integrated Circuits (AREA)
Description
【発明の詳細な説明】
〔発明の属する技術分野〕
本発明は、光IC素子を利用して温度や歪、磁
界等の各種物理量を検出する光ICセンサに関す
るものである。更に詳しくは、本発明はLiNbO3
などの光学結晶にTiなどを拡散した光導波路を
形成した光IC素子を用い、光導波路を通る光の
強度や位相等が、被測定物理量に応じて変化する
ことを利用した光ICセンサに関するものである。DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an optical IC sensor that detects various physical quantities such as temperature, strain, and magnetic field using an optical IC element. More specifically, the present invention provides LiNbO 3
An optical IC sensor that utilizes the fact that the intensity, phase, etc. of light passing through the optical waveguide changes depending on the physical quantity to be measured, using an optical IC element in which an optical waveguide is formed by diffusing Ti or the like in an optical crystal such as It is.
第１図は、従来公知の光ICを利用したセンサ
の一例を示す構成ブロツク図である。この装置
は、光源１からの光を、光フアイバ２１を介して
光IC素子３に供給し、ここからの信号光を光フ
アイバ２２を介して受光素子４に伝送するように
構成されている。光IC素子３には２本の光導波
路３１，３２が形成されるとともに、一方の光導
波路３１に物理量変化が与えられるもので、受光
素子４で検出される光の強さ、又は位相変化から
物理量を知ることができる。
FIG. 1 is a block diagram showing an example of a sensor using a conventionally known optical IC. This device is configured to supply light from a light source 1 to an optical IC element 3 via an optical fiber 21, and to transmit signal light from there to a light receiving element 4 via an optical fiber 22. Two optical waveguides 31 and 32 are formed in the optical IC element 3, and a physical quantity change is given to one of the optical waveguides 31, and a physical quantity change is applied to one of the optical waveguides 31 based on the intensity or phase change of the light detected by the light receiving element 4. You can know physical quantities.
このような構成の従来装置においては、光を供
給する光フアイバ２１と、信号光を伝送する光フ
アイバ２２との２本の光フアイバを必要とし、検
出端であるところの光IC素子を遠隔地に設置す
る場合、取扱いが煩しいうえに、計装コストが高
くなる等の問題点があつた。 A conventional device with such a configuration requires two optical fibers, the optical fiber 21 that supplies light and the optical fiber 22 that transmits signal light, and the optical IC element that is the detection end is connected to a remote location. When installing the system, there were problems such as cumbersome handling and high instrumentation costs.
ここにおいて、本発明は従来技術における問題
点を解決するためになされたもので、光IC素子
との間が１本の光フアイバで結合される装置を実
現しようとするものである。
The present invention has been made to solve the problems in the prior art, and is intended to realize a device that is coupled to an optical IC element using a single optical fiber.
本発明に係る装置は、光学結晶に光導波路を作
るとともにこの光導波路に反射部を設け、被測定
物理量に応じて変化する光路差変化を光の干渉に
より検出する光IC素子と、この光IC素子に一端
が結合し光の供給と信号光の伝送を行なう１本の
光フアイバと、この光フアイバの他端に光学的に
結合する光源及び受光素子とで構成される。
The device according to the present invention includes an optical IC element that creates an optical waveguide in an optical crystal, provides a reflecting part in the optical waveguide, and detects a change in optical path difference that changes depending on a physical quantity to be measured by interference of light, It consists of an optical fiber whose one end is coupled to an element for supplying light and transmitting signal light, and a light source and a light receiving element which are optically coupled to the other end of this optical fiber.
第２図は本発明に係る装置の一例を示す構成説
明図である。この図において、１はコヒーレント
光を出射する光源、４は受光素子、５は、光源１
と受光素子４にそれぞれ結合する２つの光導波路
５１，５２が形成された光分岐結合素子である。
３は被測定物理量を検出する検出端に設置した光
IC素子である。この光IC素子３は、例えばニオ
ブ酸リチウム等の光学結晶基板３０に、例えば
Ti等を拡散して第１、第２の光導波路３１，３
２を形成するとともに、各光導波路の他端に反射
板３４をそれぞれ設けて構成されている。また、
第１の光導波路３１には、被測定物理量３３が与
えられ、その長さあるいは屈折率が被測定物理量
に応じて変化するようになつている。２は光分岐
結合素子５と光IC素子３とを結ぶ光フアイバで、
光源１からの光を光IC素子３の各光導波路３１，
３２に導びくとともに、ここからの反射光を受光
素子４に導びく。
FIG. 2 is a configuration explanatory diagram showing an example of the apparatus according to the present invention. In this figure, 1 is a light source that emits coherent light, 4 is a light receiving element, and 5 is a light source 1
This is an optical branching/coupling element in which two optical waveguides 51 and 52 are formed, which are coupled to the light receiving element 4 and the light receiving element 4, respectively.
3 is the light installed at the detection end to detect the physical quantity to be measured
It is an IC element. This optical IC element 3 is mounted on an optical crystal substrate 30 made of, for example, lithium niobate.
The first and second optical waveguides 31 and 3 are formed by diffusing Ti, etc.
2, and a reflecting plate 34 is provided at the other end of each optical waveguide. Also,
A physical quantity to be measured 33 is provided to the first optical waveguide 31, and its length or refractive index changes depending on the physical quantity to be measured. 2 is an optical fiber connecting the optical branching/coupling element 5 and the optical IC element 3;
The light from the light source 1 is transmitted through each optical waveguide 31 of the optical IC element 3,
32, and the reflected light from here is also guided to the light receiving element 4.
このように構成した装置の動作は次の通りであ
る。光源１からの光は、光分岐結合素子５の光導
波路５１及び光フアイバ２を通つて、光IC素子
３の第１、第２の光導波路３１，３２に導びかれ
る。ここで、第１、第２の光導波路３１，３２の
光路長をそれぞれL1，L2、屈折率をそれぞれN1，
N2とすると、第１の光導波路３１にのみ被測定
物理量３３が与えられているので、L1及び又は
N1のみが、この被測定物理量に応じて変化する
こととなる。各光導波路３１，３２の他端に導び
かれた光は、反射板３４で反射し、同じ光導波路
３１，３２を戻り、ひとつの光導波路の部分で干
渉し、これが信号光として、光フアイバ２を通
り、受光素子４側に伝送される。よつて、受光素
子４で検出される信号光の強度Ｐは、(1)式で表わ
すことができる。 The operation of the device configured as described above is as follows. Light from the light source 1 passes through the optical waveguide 51 of the optical branching/coupling element 5 and the optical fiber 2, and is guided to the first and second optical waveguides 31 and 32 of the optical IC element 3. Here, the optical path lengths of the first and second optical waveguides 31 and 32 are L 1 and L 2 , respectively, and the refractive indexes are N 1 and N 1 , respectively.
If N 2 , since the physical quantity to be measured 33 is given only to the first optical waveguide 31, L 1 and or
Only N 1 changes depending on this physical quantity to be measured. The light guided to the other end of each optical waveguide 31, 32 is reflected by the reflection plate 34, returns through the same optical waveguide 31, 32, and interferes at a portion of one optical waveguide, and this light is transmitted as signal light to the optical fiber. 2 and is transmitted to the light receiving element 4 side. Therefore, the intensity P of the signal light detected by the light receiving element 4 can be expressed by equation (1).
Ｐ＝P0（１＋cosΔφ） (1)
ただし、
Δφ＝2π／λ0（2N1L1−2N2L2）
P0：Δφ＝０のときの光強度
λ0：光源１の波長
(1)式から明らかな様に、受光素子４で検出され
る信号光の強度Ｐは、第１、第２の光導波路３
１，３２の光路長変化または屈折率変化に対応す
るもので、これから、第１の光導波路３１に与え
られている被測定物理量を知ることができる。 P=P 0 (1+cosΔφ) (1) However, Δφ=2π/λ 0 (2N 1 L 1 −2N 2 L 2 ) P 0 : Light intensity when Δφ=0 λ 0 : Wavelength of light source 1 (1) As is clear from the equation, the intensity P of the signal light detected by the light receiving element 4 is
This corresponds to the optical path length change or refractive index change of 1 and 32, and from this, the measured physical quantity given to the first optical waveguide 31 can be known.
第３図は本発明の第２の実施例を示す構成説明
図である。この実施例においては、波長λ1，λ2の
２種の光を、光源１１，１２から光IC素子３側
に供給するとともに、光IC素子３に波長λ2の光
を導びく第３、第４の光導波路３６，３７を形成
させ、この光IC素子３から光フアイバ２を通つ
て戻つてくる信号光を、波長λ1，λ2をそれぞれ通
過させるフイルタ５５，５６を介して受光素子４
１，４２で検出するようにしたものである。光
IC素子３において、第１、第２の光導波路３１，
３２には、波長λ1の光がそれぞれ導びかれ、第１
の光導波路３１に被測定物理量３３が与えられて
いる。３８，３９は、波長λ1，λ2を通過させるフ
イルタである。 FIG. 3 is a configuration explanatory diagram showing a second embodiment of the present invention. In this embodiment, two types of light with wavelengths λ 1 and λ 2 are supplied from light sources 11 and 12 to the optical IC element 3 side, and a third type of light, which guides light with wavelength λ 2 to the optical IC element 3, is supplied to the optical IC element 3 side. Fourth optical waveguides 36 and 37 are formed, and the signal light returning from the optical IC element 3 through the optical fiber 2 is passed through filters 55 and 56 that pass wavelengths λ 1 and λ 2, respectively, to the light receiving element. 4
1 and 42 for detection. light
In the IC element 3, the first and second optical waveguides 31,
32, the light of wavelength λ 1 is guided respectively, and the first
A physical quantity to be measured 33 is given to the optical waveguide 31 . 38 and 39 are filters that allow wavelengths λ 1 and λ 2 to pass.
この実施例においては、受光素子４１で検出さ
れる波長λ1の信号光の強度Ｐは、被測定物理量及
び、光フアイバ２の伝送条件等の変化に応じて変
化する。一方、受光素子４２で検出される波長λ2
の信号光の強度は、被測定物理量とは無関係で、
光フアイバ２の伝送条件等の影響を受けて変化す
る。従つて、各受光素子４１，４２から得られる
信号を利用し、例えば除算演算等の処理を行なう
ことによつて、光フアイバ２の伝送条件等の影響
を受けず、被測定物理量を知ることができる。 In this embodiment, the intensity P of the signal light having the wavelength λ 1 detected by the light receiving element 41 changes depending on changes in the physical quantity to be measured, the transmission conditions of the optical fiber 2, and the like. On the other hand, the wavelength λ 2 detected by the light receiving element 42
The intensity of the signal light is independent of the physical quantity to be measured,
It changes depending on the transmission conditions of the optical fiber 2, etc. Therefore, by using the signals obtained from each of the light receiving elements 41 and 42 and performing processing such as a division operation, it is possible to know the physical quantity to be measured without being affected by the transmission conditions of the optical fiber 2, etc. can.
なお、被測定物理量としては、熱、力、輻射、
磁気変化、湿度などが考えられ、これらの測定物
理量に応じて、光IC素子３や第１の光導波路３
１の構造が適当に選定される。例えば、輻射を測
定する場合には、第１の光導波路付近に黒体を塗
り、磁気変化測定の場合には、磁性材料を設置
し、また、湿度変化測定の場合には、吸湿剤を用
いるなど、構造上の工夫がなされる。 The physical quantities to be measured include heat, force, radiation,
Magnetic changes, humidity, etc. are considered, and depending on these measured physical quantities, the optical IC element 3 and the first optical waveguide 3
1 structure is appropriately selected. For example, when measuring radiation, a black body is painted near the first optical waveguide, when measuring magnetic changes, a magnetic material is installed, and when measuring humidity changes, a moisture absorbent is used. Structural improvements have been made, such as:
以上説明したように、本発明によれば検出端と
なる光IC素子には１本の光フアイバが結合する
もで、取扱いが簡単で、計装コストが安価な光
ICセンサが実現できる。また、本発明の第２の
実施例によれば、光フアイバの伝送条件の変化に
よる影響を受けない装置が実現できる。
As explained above, according to the present invention, a single optical fiber is coupled to the optical IC element serving as the detection end, and the optical IC element is easy to handle and has low instrumentation cost.
IC sensor can be realized. Furthermore, according to the second embodiment of the present invention, it is possible to realize a device that is not affected by changes in optical fiber transmission conditions.
第１図は従来技術の一例を示す構成ブロツク
図、第２図及び第３図は本発明に係る装置の一例
を示す構成説明図である。
１，１１，１２……光源、４，４１，４２……
受光素子、２……光フアイバ、３……光IC素子、
３１，３２……第１、第２の光導波路、３３……
被測定物理量、３４……反射板、５……光分岐結
合素子。
FIG. 1 is a configuration block diagram showing an example of a conventional technique, and FIGS. 2 and 3 are configuration explanatory diagrams showing an example of an apparatus according to the present invention. 1, 11, 12... light source, 4, 41, 42...
Light receiving element, 2... optical fiber, 3... optical IC element,
31, 32...first and second optical waveguides, 33...
Physical quantity to be measured, 34... Reflection plate, 5... Optical branching and coupling element.
Claims (1)
前記光源と受光素子に光学的に結合する光分岐結
合素子、この光分岐結合素子に結合する１本の光
フアイバ、この光フアイバを通つた光が導びかれ
る第１、第２の光導波路とこれら第１、第２の光
導波路を通つた光をそれぞれ反射させる反射部と
を有する光IC素子、前記第１の光導波路に被測
定物理量を与える手段を具備し、前記光IC素子
からの光を前記光フアイバを介して受光素子で検
出するようにした光ICセンサ。 ２ 波長λ1，λ2のコヒーレント光を出射する光
源、波長λ1，λ2の光を受光する第１、第２の受光
素子、前記光源と前記第１、第２の受光素子に光
学的に結合する光分岐結合素子、この光分岐結合
素子に結合する１本の光フアイバ、この光フアイ
バを通つた光であつて波長λ1の光が導びかれる第
１、第２の光導波路と波長λ2の光が導びかれる第
３、第４の光導波路と第１〜第４の光導波路を通
つた光をそれそれぞれ反射させる反射部とを有す
る光IC素子、前記第１の光導波路に被測定物理
量を与える手段を具備し、前記光IC素子からの
光を前記光フアイバを介して前記第１、第２の受
光素子で検出し、各受光素子から得られる信号を
演算処理するようにした光ICセンサ。[Claims] 1. A light source that emits coherent light, a light receiving element,
an optical branching/coupling element optically coupled to the light source and the light receiving element; an optical fiber coupled to the optical branching/coupling element; first and second optical waveguides through which light passing through the optical fiber is guided; An optical IC element having a reflecting part that reflects the light passing through the first and second optical waveguides, a means for applying a physical quantity to be measured to the first optical waveguide, and a light from the optical IC element. An optical IC sensor in which the light is detected by a light-receiving element via the optical fiber. 2. A light source that emits coherent light with wavelengths λ 1 and λ 2 , first and second light receiving elements that receive light with wavelengths λ 1 and λ 2 , and an optical link between the light source and the first and second light receiving elements. an optical branching/coupling element coupled to the optical branching/coupling element, an optical fiber coupled to the optical branching/coupling element, first and second optical waveguides through which light having a wavelength λ 1 passing through the optical fiber is guided; an optical IC element having third and fourth optical waveguides to which light with a wavelength λ 2 is guided, and reflecting portions that respectively reflect the light that has passed through the first to fourth optical waveguides, the first optical waveguide; means for giving a physical quantity to be measured to the optical IC element, the light from the optical IC element is detected by the first and second light receiving elements via the optical fiber, and the signals obtained from each light receiving element are subjected to arithmetic processing. optical IC sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58101495A JPS59226832A (en) | 1983-06-07 | 1983-06-07 | Optical ic sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58101495A JPS59226832A (en) | 1983-06-07 | 1983-06-07 | Optical ic sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59226832A JPS59226832A (en) | 1984-12-20 |
| JPH0376693B2 true JPH0376693B2 (en) | 1991-12-06 |
Family
ID=14302235
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58101495A Granted JPS59226832A (en) | 1983-06-07 | 1983-06-07 | Optical ic sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59226832A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150192174A1 (en) * | 2012-09-19 | 2015-07-09 | Ntn Corporation | Wind/tidal power generation bearing |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61182541A (en) * | 1985-02-08 | 1986-08-15 | Hamamatsu Photonics Kk | Infrared-ray detector |
| JPS6319572A (en) * | 1986-07-12 | 1988-01-27 | Fujikura Ltd | Magnetic sensor |
| EP0768516A1 (en) * | 1995-10-16 | 1997-04-16 | European Community | Interferometer optical transducer and relative fabrication method |
| GB9713018D0 (en) | 1997-06-20 | 1997-08-27 | Secr Defence | Optical fibre bend sensor |
-
1983
- 1983-06-07 JP JP58101495A patent/JPS59226832A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150192174A1 (en) * | 2012-09-19 | 2015-07-09 | Ntn Corporation | Wind/tidal power generation bearing |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59226832A (en) | 1984-12-20 |
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