JPS59226832A - Optical ic sensor - Google Patents
Optical ic sensorInfo
- Publication number
- JPS59226832A JPS59226832A JP58101495A JP10149583A JPS59226832A JP S59226832 A JPS59226832 A JP S59226832A JP 58101495 A JP58101495 A JP 58101495A JP 10149583 A JP10149583 A JP 10149583A JP S59226832 A JPS59226832 A JP S59226832A
- Authority
- JP
- Japan
- Prior art keywords
- optical
- light
- optical fiber
- waveguide
- 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.)
- Granted
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 88
- 239000013307 optical fiber Substances 0.000 claims abstract description 25
- 230000008878 coupling Effects 0.000 claims abstract description 9
- 238000010168 coupling process Methods 0.000 claims abstract description 9
- 238000005859 coupling reaction Methods 0.000 claims abstract description 9
- 230000001427 coherent effect Effects 0.000 claims description 2
- 230000005540 biological transmission Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 230000005855 radiation Effects 0.000 description 2
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000835 fiber Substances 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
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)
- Spectrometry And Color Measurement (AREA)
- Optical Integrated Circuits (AREA)
- Measuring Temperature Or Quantity Of Heat (AREA)
- Measuring Magnetic Variables (AREA)
Abstract
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七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 optical IC elements.
更に詳しくは、本発明はＬｉＮｂ０ などの光学結晶に
Ｔ１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センヶに関する
ものである。More specifically, the present invention uses an optical IC device in which an optical waveguide in which T1 or the like is diffused is formed in an optical crystal such as LiNb0, and the intensity, phase, etc. of light passing through the optical waveguide change depending on the physical quantity to be measured. This article relates to an optical IC sensor that utilizes.
第１図は、従来公知の光ＩＣｉ利用したセンブの一例を
示す構成プロ／り図である。この装置は、光源１からの
光を、光フアイバ２工を介して光ＩＣ素子５に供給し、
ここがらの信号光を光ファイバ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素子乙には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 configuration diagram showing an example of a conventionally known module using optical ICi. This device supplies light from a light source 1 to an optical IC element 5 via an optical fiber 2,
These signal lights are sent to the light receiving element 4 via the optical fiber 22.
is configured to transmit to. Optical IC element B has 2
Two optical waveguides 31 and 32 are formed, and a physical quantity change is applied to one of the optical waveguides 31, and the physical quantity can be determined from the intensity or phase change of the light detected by the light receiving element 4.
このような構成の従来装置においては、光音供給する光
ファイバ２１と、信号光を伝送する光ファイバ２２との
２本の光ファイバを必要とし、検出端であるところの光
ＩＣ素子を遠隔地に設置する揚台、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った。A conventional device with such a configuration requires two optical fibers, the optical fiber 21 for supplying optical sound and the optical fiber 22 for transmitting signal light, and the optical IC element, which is the detection end, is connected to a remote location. There were problems such as the lifting platform installed on the ground, which was cumbersome to handle, and increased 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７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 by one optical fiber.
本発明に係る装置は一１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本の光ファイバと、この光７フィバ
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 is an optical IC 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 IC element, an optical fiber whose one end is coupled to the optical IC 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 the optical IC element. Ru.
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。５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載板３０に、例えば
Ｔ１等を拡散イ
して第１ｊ第２の光導波路３１．３２を形成するとさ・
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っている。２は光分
岐結合素子５と光ＩＣ素子３とを結ぶ光ファイバで、光
源１がらの光を光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釦導ひ
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 an optical branching and coupling element in which two optical waveguides 51 and 52 are formed, which are coupled to the light source 1 and the light receiving element 4, respectively. Reference numeral 5 denotes an optical IC element installed at the detection end for detecting the physical quantity to be measured. This optical IC element 3 is constructed by diffusing, for example, T1 on an optical crystal mounting plate 30 made of, for example, lithium niobate to form a 1j-th second optical waveguide 31, 32.
In addition, a reflecting plate 34 is provided at the other end of each optical waveguide. Further, the first optical waveguide 31 is provided with a physical quantity to be measured 33, and its length or refractive index changes depending on the physical quantity to be measured. Reference numeral 2 denotes an optical fiber connecting the optical branching/coupling element 5 and the optical IC element 3, which guides the light from the light source 1 to each optical waveguide 31, 32 of the optical IC element 3, and transmits the reflected light from there to the light receiving element 4. Pull the button.
このように構成した装置の動作は次の通シである。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
ファイバ２を通って、光ＩＣ素子３の第１１第２の光導
波路３１．３２に導びがれる。ここ４゜
で、第１．第２光導波路３．１．３２の光路長をそれぞ
れＬｌ、 Ｌ２．屈折率をそれぞれＮ１ｐ 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
ら九ているので、Ｌ□及び又はＮ１のみが、この被測定
物理−ｈｔに応じて変化することとなる。各光導波路３
１゜３２の他端に導びがれた光は、反射板３４で反射し
、同じ光導波路３１．３２’（（戻り、ひとつの光導波
路の部分で干渉し、これが４１号光として、光ファイバ
２を通り、受光素子４側に伝送される。よって、受光素
子４で検出される信号光の強度Ｐは、（１）式％式％
）（１）
ただし、
２π
Δφ“ｒ （２Ｎ１Ｌ１−２Ｎ２Ｌ２）ｐｏ：Δφ＝
（＋のときの光強度
λ０：光源１０波長
（り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３１゜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。The operation of the device configured as described above is as follows. The 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 eleventh and second optical waveguides 31 and 32 of the optical IC element 3. Here at 4 degrees, the first. The optical path lengths of the second optical waveguides 3.1.32 are Ll, L2. When the refractive index is N1p and N2, respectively, since the physical quantity to be measured 33 is given only to the first optical waveguide 31, only L□ and/or N1 changes according to the physical quantity to be measured -ht. Become. Each optical waveguide 3
The light guided to the other end of 1°32 is reflected by the reflection plate 34 and passes through the same optical waveguide 31. It passes through the 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 is expressed as follows: 2N2L2)po:Δφ=
(Light intensity λ0 when +: light source 10 wavelength (As is clear from the equation, the intensity P of the signal light detected by the light receiving element 4 is the change in the optical path length of the first and second optical waveguides 31° and 32. Or, it corresponds to the change in refractive index, and from now on,
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素子から光ファイバ２を通って戻ってくる信号１゜
光を、波長λ４．λ２をそれぞれ通過させるフィルタ５
５、５６を介して受光素子４１．４２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の光がそれぞれ導ひ
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λ４．λ２を通過させる
フィルタである。FIG. 3 is a configuration explanatory diagram showing a second embodiment of the present invention. In this embodiment, the wavelength λ1. Two types of light with wavelength λ2 are supplied from the light sources 11 and 12 to the optical IC element 3 side, and a third light source 11.12 which guides the light with wavelength λ2 to the optical IC element 3. A fourth optical waveguide 36, 37 is formed, and the signal 1° light returning from this optical IC element through the optical fiber 2 is transmitted at a wavelength of λ4. Filters 5 each passing λ2
5 and 56, and are detected by light receiving elements 41 and 42. In the optical IC element 3, the first. Light of wavelength λ1 is guided to the second optical waveguides 31 and 32, respectively, and the physical quantity to be measured 33 is provided to the first optical waveguide 31. 38.39 is the wavelength λ4. This is a filter that allows λ2 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、光ファイ
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、光ファイバ２の伝送条件等の影
響を受けて変化する。従って、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
なうことによって、光ファイバ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 λ1 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 intensity of the signal light having the wavelength λ2 detected by the light receiving element 42 is independent of the physical quantity to be measured and changes under the influence of the transmission conditions of the optical fiber 2 and the like. Therefore, by using the signals obtained from each light-receiving element 41, 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.
なお、被測定物理量としては、熱、カ、輻射。The physical quantities to be measured are heat, force, and radiation.
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６や第１の光導波路３１の構造が適
当に選定式れる。例えは、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。Magnetic changes, humidity, etc. are considered, and the structures of the optical IC element 6 and the first optical waveguide 31 are appropriately selected depending on these measured physical quantities. 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 applied. Structural improvements have been made, such as using
以上説明したように、本発明によれば検出端となる光Ｉ
Ｃ素子には１本の光ファ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七ンプが実現できる
。また、本発明の第２の実施例によれば、光ファイバの
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, the light I serving as the detection end
A single optical fiber is coupled to the C element, making it possible to realize an optical IC amplifier that is easy to handle and has low instrumentation costs. 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４（１７成ブロック図、
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・・・光ファイバ、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 shows an example of the prior art.
FIGS. 2 and 3 are configuration explanatory diagrams showing an example of the 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...1st. 2nd optical waveguide, 33... physical quantity to be measured, 34... reflecting plate, 5... optical branching and coupling element.
Claims (1)
光ファイバ、この光ファイバを通った光が導びかれる第
１．第２の光導波路とこれら第１１第２の光導波路を通
った光をそれぞれ反射させる反射部とを有する光重Ｃ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ＸＣ素子からの光を前記光ファイバを介
して受光素子で検出するようにした光ＩＣ七ンサ。 （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
本の光フ丁イパ、この光ファイバを通った光であって波
長λ１の光が導びかれる第１．第２の光導波・路と波長
λ２の光が導ひかれる第３．第４の光導波路と第１〜第
４０光導波路を通った光をそれぞ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
を前記光ファ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七ンサ。[Claims] (A light source that emits recoherent light, a light receiving element, an optical fiber, a first and second optical waveguide through which light passing through this optical fiber is guided, and these eleventh and second optical waveguides) an optical heavy C element having a reflecting part that reflects the light that has passed through the waveguide, a means for applying a physical quantity to be measured to the first optical waveguide, and the light from the optical XC element is transmitted through the optical fiber. An optical IC seven sensor configured to detect light with a light receiving element. (2) A light source that emits coherent light with wavelengths λ1 and λ2, first and second light receiving elements that receive light with wavelengths λ1 and λ2, the light source and the light receiving element. 1. A light branching/coupling element optically coupled to the second light receiving element, a light branching/coupling element coupled to this light branching/coupling element.
In the optical fiber of the book, the light that has passed through this optical fiber and has a wavelength of λ1 is guided to the first. The second optical waveguide/path and the third optical path through which the light of wavelength λ2 is guided. an optical IC element having a fourth optical waveguide and a reflecting section that reflects the light that has passed through the first to fortieth optical waveguides, a means for applying a physical quantity to be measured to the first optical waveguide; The light from the optical IC element is passed through the optical fiber to the first. An optical IC seven sensor that detects with a second light-receiving element and performs arithmetic processing on the signals obtained from each light-receiving element.
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 true JPS59226832A (en) | 1984-12-20 |
| JPH0376693B2 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 (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 |
| WO1998059219A2 (en) * | 1997-06-20 | 1998-12-30 | The Secretary Of State For Defence | Optical fibre bend sensor |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014059025A (en) * | 2012-09-19 | 2014-04-03 | Ntn Corp | Bearing for wind power/tidal power generation |
-
1983
- 1983-06-07 JP JP58101495A patent/JPS59226832A/en active Granted
Cited By (11)
| 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 |
| WO1998059219A2 (en) * | 1997-06-20 | 1998-12-30 | The Secretary Of State For Defence | Optical fibre bend sensor |
| WO1998059219A3 (en) * | 1997-06-20 | 1999-04-29 | Secr Defence | Optical fibre bend sensor |
| GB2341445A (en) * | 1997-06-20 | 2000-03-15 | Secr Defence | Optical fibre bend sensor |
| EP1134556A2 (en) * | 1997-06-20 | 2001-09-19 | QinetiQ Limited | Optical fibre bend sensor |
| GB2341445B (en) * | 1997-06-20 | 2002-01-02 | Secr Defence | Optical fibre bend sensor |
| EP1134556A3 (en) * | 1997-06-20 | 2002-04-10 | QinetiQ Limited | Optical fibre bend sensor |
| US6389187B1 (en) | 1997-06-20 | 2002-05-14 | Qinetiq Limited | Optical fiber bend sensor |
| US6621956B2 (en) | 1997-06-20 | 2003-09-16 | Qinetiq Limited | Optical fibre bend sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0376693B2 (en) | 1991-12-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4356396A (en) | Fiber optical measuring device with compensating properties | |
| US4320475A (en) | Monomodal optical fibre hydrophone operating by the elastooptical effect | |
| US4759627A (en) | Fibre-optic interferometer | |
| CN102636217B (en) | Sensing device based on joint detection of Brillouin optical time domain analysis and Mach-Zehnder interference | |
| US4882716A (en) | Optic fiber hydrophone and antenna associating a series of hydrophones | |
| JPS61270632A (en) | Optical fiber type measuring instrument for temperature distribution | |
| CN108844614A (en) | Chaos Brillouin light domain of dependence analysis system and method based on phase spectrometry | |
| JPH02116716A (en) | Fiber optical sensor | |
| US4727254A (en) | Dual wavelength microbend sensor | |
| CN101290248B (en) | Single-mode infra-red wavemeter based on Mach-Zehnder Interferometer filtering principle | |
| US6285182B1 (en) | Electro-optic voltage sensor | |
| US4430565A (en) | Correlating fiber optical measuring device | |
| EP0184270A3 (en) | Fiber coupler displacement transducer | |
| JPS59226832A (en) | Optical ic sensor | |
| Toda et al. | Integrated-optic heterodyne interferometer for displacement measurement | |
| CN201373781Y (en) | Semiconductor absorption optical fiber temperature detection device | |
| JPS63113337A (en) | Method and device for compensating fiber optic lead loss and connector loss in fiber optic sensor | |
| JPH02118416A (en) | Optical sensor | |
| JP2003270041A (en) | Apparatus for high-speed detection of wavelength | |
| JPS5915841A (en) | Refractive index measuring apparatus | |
| JPS6144334A (en) | Temperature measuring device | |
| JPS6252808B2 (en) | ||
| JPS5960699A (en) | Optical sensor | |
| RU2036419C1 (en) | Fibre-optical indicator of outside action | |
| Dandridge et al. | Increasing Multiplexed Fiber Sensor Array Performance by Use of a Singlemode/Multimode Recombiner |