JP3388373B2 - Magnetic field sensor - Google Patents
Magnetic field sensorInfo
- Publication number
- JP3388373B2 JP3388373B2 JP12781794A JP12781794A JP3388373B2 JP 3388373 B2 JP3388373 B2 JP 3388373B2 JP 12781794 A JP12781794 A JP 12781794A JP 12781794 A JP12781794 A JP 12781794A JP 3388373 B2 JP3388373 B2 JP 3388373B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- magnetic
- optical waveguide
- substrate
- phase shift
- 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 - Fee Related
Links
Landscapes
- Measuring Magnetic Variables (AREA)
- Optical Integrated Circuits (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、磁界を光を用いて検出
する磁界センサに関し、特に分岐干渉型光導波路を用い
た磁界センサに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic field sensor for detecting a magnetic field using light, and more particularly to a magnetic field sensor using a branch interference type optical waveguide.
【０００２】[0002]
【従来の技術】従来より、配電線等の電流が形成する磁
界を測定する磁界センサとしては、リング状の磁性体コ
アと磁気検出素子（ホール素子、磁気抵抗素子等）を用
い、磁界を検出して電流値に換算し出力するものが一般
的であるが、特に高電圧を取り扱う分野では高い電気絶
縁性と各種の電磁誘導性による妨害を受けない等のため
に磁界を光を用いて検出する磁界センサが用いられるよ
うになっている。この磁界センサは、光の進行方向に磁
界が加わると光の偏光面が回転するファラデー効果を有
するファラデー素子を用いて磁界を検出するものであ
る。2. Description of the Related Art Conventionally, as a magnetic field sensor for measuring a magnetic field formed by a current of a distribution line or the like, a ring-shaped magnetic core and a magnetic detection element (Hall element, magnetic resistance element, etc.) are used to detect a magnetic field. It is common to convert the current value into a current value and output it.However, especially in the field of handling high voltage, the magnetic field is detected using light because it has high electrical insulation and is not disturbed by various electromagnetic inductions. A magnetic field sensor is used. This magnetic field sensor detects a magnetic field using a Faraday element having a Faraday effect in which the plane of polarization of light rotates when a magnetic field is applied in the traveling direction of light.
【０００３】[0003]
【発明が解決しようとする課題】しかし、従来の磁界セ
ンサは、磁界に対する感度が比較的低いファラデー素子
を磁気検出素子として用いていることから微小な電流に
よる微小な磁界を検出するには感度が足りないという問
題があった。However, since the conventional magnetic field sensor uses a Faraday element, which has a relatively low sensitivity to a magnetic field, as a magnetic detection element, the sensitivity is low for detecting a minute magnetic field due to a minute current. There was a shortage.
【０００４】これを解決するため、ファラデー素子の表
面に反射膜を設け、ファラデー素子を透過する光を複数
回反射させ光路長を長くすることにより、あるいは磁性
体コアの断面より小さい磁性体からなる保持部材を用い
ることによりファラデー素子を透過する磁束の量を増加
させることにより、感度を向上させる磁界センサが提案
されているがまだ不十分である。In order to solve this, a reflection film is provided on the surface of the Faraday element, and light passing through the Faraday element is reflected a plurality of times to lengthen the optical path length, or a magnetic body smaller than the cross section of the magnetic core is used. A magnetic field sensor that improves sensitivity by increasing the amount of magnetic flux that passes through the Faraday element by using a holding member has been proposed, but is still insufficient.
【０００５】本発明の目的は、感度を十分に向上するこ
とができる磁界センサを提供することにある。An object of the present invention is to provide a magnetic field sensor capable of sufficiently improving the sensitivity.
【０００６】[0006]
【課題を解決するための手段】本発明は、前記の課題を
解決するために、基板と、この基板に形成され磁気複屈
折効果を有する入射光導波路と、前記基板に前記入射光
導波路より分岐するように形成され磁気複屈折効果を有
する２つの位相シフト光導波路と、前記基板に前記位相
シフト光導波路が合流するように形成され磁気複屈折効
果を有する出射光導波路とを具備する磁界センサにおい
て、前記位相シフト光導波路のいずれかひとつの位相シ
フト光導波路の１部を磁化反転させた磁化反転部を有す
ることを特徴とする。In order to solve the above-mentioned problems, the present invention provides a substrate, an incident optical waveguide having a magnetic birefringence effect formed on the substrate, and a branch from the incident optical waveguide to the substrate. A magnetic field sensor comprising: two phase shift optical waveguides formed so as to have a magnetic birefringence effect; and an output optical waveguide having a magnetic birefringence effect formed so that the phase shift optical waveguides join the substrate. It is characterized by having a magnetization reversal part obtained by reversing a part of one of the phase shift optical waveguides.
【０００７】また、本発明は、基板と、この基板に形成
され磁気複屈折効果を有する入射光導波路と、前記基板
に前記入射光導波路より分岐するように形成され磁気複
屈折効果を有する２つの位相シフト光導波路と、前記基
板に前記位相シフト光導波路が合流するように形成され
磁気複屈折効果を有する出射光導波路とを具備する磁界
センサにおいて、前記位相シフト光導波路のそれぞれの
１部を磁化反転させた磁化反転部を有し、かつ、これら
の磁化反転部の長さが異なることを特徴とする。Further, according to the present invention, a substrate, an incident optical waveguide having a magnetic birefringence effect formed on the substrate, and two substrates having a magnetic birefringence effect formed on the substrate so as to be branched from the incident optical waveguide. In a magnetic field sensor comprising a phase shift optical waveguide and an output optical waveguide having a magnetic birefringence effect formed so that the phase shift optical waveguide merges with the substrate, each part of the phase shift optical waveguide is magnetized. It is characterized in that it has an inverted magnetization reversal portion and that the magnetization reversal portions have different lengths.
【０００８】[0008]
【実施例】次に、本発明の実施例を詳細に説明する。EXAMPLES Next, examples of the present invention will be described in detail.
【０００９】図１は、本発明の第１の実施例を示す正面
図である。図１に示すように、本発明の磁界センサは、
基板１と、この基板１に形成され磁気複屈折効果を有す
る入射光導波路２と、前記基板１に前記入射光導波路２
より分岐するように形成され磁気複屈折効果を有する２
つの位相シフト光導波路３，４と、前記基板１に前記位
相シフト光導波路３，４が合流するように形成され磁気
複屈折効果を有する出射光導波路５とを具備する。前記
位相シフト光導波路３は、その１部を磁化反転させた磁
化反転部６を有する。FIG. 1 is a front view showing a first embodiment of the present invention. As shown in FIG. 1, the magnetic field sensor of the present invention is
Substrate 1, incident optical waveguide 2 formed on the substrate 1 and having a magnetic birefringence effect, and incident optical waveguide 2 on the substrate 1.
It is formed to be more branched and has a magnetic birefringence effect 2
The phase shift optical waveguides 3 and 4 and the output optical waveguide 5 having the magnetic birefringence effect are formed on the substrate 1 so that the phase shift optical waveguides 3 and 4 merge. The phase shift optical waveguide 3 has a magnetization reversal portion 6 in which a part of the phase shift optical waveguide 3 is magnetized.
【００１０】前記入射光導波路２には、入射光ファイバ
７が接続されている。この入射光ファイバ７には、レー
ザ装置などの光源から光が入射される。前記出射光導波
路５には、出射光ファイバ８が接続されている。この出
射光ファイバ８には、これから出射される光の強弱を測
定する光測定器に接続されている。An incident optical fiber 7 is connected to the incident optical waveguide 2. Light is incident on the incident optical fiber 7 from a light source such as a laser device. An output optical fiber 8 is connected to the output optical waveguide 5. The emission optical fiber 8 is connected to an optical measuring device that measures the intensity of light emitted from this.
【００１１】図２は、本発明の第２の実施例を示す正面
図である。図２に示す第２の実施例は、図１の第１の実
施例と同一の符号の要素を有している。第２の実施例に
おいては、前記位相シフト光導波路３，４は、それぞれ
の１部を磁化反転させた磁化反転部６，６´を有し、か
つ、これらの磁化反転部６，６´の長さが異なる。FIG. 2 is a front view showing a second embodiment of the present invention. The second embodiment shown in FIG. 2 has elements with the same reference numerals as the first embodiment of FIG. In the second embodiment, the phase shift optical waveguides 3 and 4 have magnetization reversal portions 6 and 6'in which the respective portions are reversibly magnetized, and the magnetization reversal portions 6 and 6'are The length is different.
【００１２】本発明においては、前記２つの位相シフト
光導波路３，４に磁界が印加された場合、２つの位相シ
フト光導波路３，４の屈折率が変化し、２つの位相シフ
ト光導波路３，４を導波する光は位相が変化することに
なる。ここで２つの位相シフト光導波路３，４のいずれ
かひとつがその１部を反転磁化させた磁化反転部６を有
することにより、または２つの位相シフト光導波路３，
４がそれぞれの１部を磁化反転させた磁化反転部６，６
´を有し、かつ、これらの磁化反転部６，６´の長さが
異なることにより、磁界が印加された場合、２つの位相
シフト光導波路３，４を導波する光にはお互いに異なる
位相の変化量が生ずることになり、出射光導波路５から
の合波した出射光の光強度が変化することになり、この
変化量から印加された磁界の大きさを検出することがで
きる。In the present invention, when a magnetic field is applied to the two phase shift optical waveguides 3 and 4, the refractive indexes of the two phase shift optical waveguides 3 and 4 change and the two phase shift optical waveguides 3 and 4 change. The phase of the light propagating in 4 changes. Here, any one of the two phase shift optical waveguides 3 and 4 has a magnetization reversal portion 6 in which one part is inversely magnetized, or the two phase shift optical waveguides 3 and 4 are
4 is a magnetization reversal part 6, 6 in which the respective parts are reversibly magnetized.
′ 'And the lengths of these magnetization reversal portions 6 and 6 ′ are different, so that when a magnetic field is applied, the light guided through the two phase shift optical waveguides 3 and 4 are different from each other. Since the amount of change in phase is generated, the light intensity of the combined outgoing light from the outgoing optical waveguide 5 changes, and the magnitude of the applied magnetic field can be detected from this amount of change.
【００１３】ここで、磁気複屈折効果とは、光の進行方
向に対し垂直方向に磁界が印加された場合、磁界に平行
な偏光と垂直な偏光との間に位相を生じる効果であり、
たとえば、磁気複屈折効果を有する結晶から成る光導波
路の面内方向でかつ光進行方向に垂直に磁界を印加した
場合、ＴＭモードの偏光の位相がシフトすることにな
る。次に、本発明の具体的な実施例を詳細に説明する。Here, the magnetic birefringence effect is an effect of producing a phase between polarized light parallel to the magnetic field and polarized light perpendicular to the magnetic field when a magnetic field is applied in a direction perpendicular to the traveling direction of light.
For example, when a magnetic field is applied in the in-plane direction of an optical waveguide made of a crystal having a magnetic birefringence effect and perpendicularly to the light traveling direction, the phase of TM-mode polarized light is shifted. Next, specific examples of the present invention will be described in detail.
【００１４】（具体的実施例１）前記基板１は、（１１
１）面を有するガリウム・カドリニウム・ガーネット
（Ｇａ3 Ｃｄ5 Ｏ12）結晶板で形成した。この基板１の
上に、Ｌａ、Ｇａ置換イットリウム・アイアン・ガーネ
ット結晶をエビタキシャル成長させ面内磁化を有する単
結晶薄膜を作製した。(Specific Example 1) The substrate 1 is (11)
1) A gallium / cadolinium / garnet (Ga 3 Cd 5 O 12 ) crystal plate having a plane. On this substrate 1, a La, Ga-substituted yttrium iron garnet crystal was epitaxially grown to prepare a single crystal thin film having in-plane magnetization.
【００１５】次に、フォトリソグラフィーにより前記入
射光導波路２および前記位相シフト光導波路３，４のフ
ォトレジストを除去し、Ｔｉをスパッタしリフトオフに
よりフォトレジストを除去してエッチング用のマスクと
してアルゴンイオンでエッチングし、リブ型の前記入射
光導波路２および前記位相シフト光導波路３，４を作製
した。前記入射光導波路２および前記位相シフト光導波
路３，４は、幅が５〜１０μｍであり、かつ、高さが
０．５〜０．８μｍである。次に一方の位相シフト光導
波路３の１０ｍｍの長さの部分をレーザ・アニールし、
この部分を磁化反転させて磁化反転部６を形成した。さ
らに、前記入射光導波路２、前記位相シフト光導波路
３，４および磁化反転部６の上にバッファー層としてＳ
ｉＯ2 膜をスパッタにより作製した。Next, the photoresists of the incident optical waveguide 2 and the phase shift optical waveguides 3 and 4 are removed by photolithography, Ti is sputtered and the photoresist is removed by lift-off, and argon ions are used as a mask for etching. By etching, the rib type incident optical waveguide 2 and the phase shift optical waveguides 3 and 4 were produced. The incident optical waveguide 2 and the phase shift optical waveguides 3 and 4 have a width of 5 to 10 μm and a height of 0.5 to 0.8 μm. Next, a portion of the one phase shift optical waveguide 3 having a length of 10 mm is laser-annealed,
The magnetization reversal portion 6 was formed by reversing the magnetization of this portion. Further, S is provided as a buffer layer on the incident optical waveguide 2, the phase shift optical waveguides 3 and 4, and the magnetization reversal portion 6.
An iO 2 film was formed by sputtering.
【００１６】前記入射光導波路２および出射光導波路５
に、入射光ファイバ７および出射光ファイバ８を接続し
て磁界センサ（図１）を作製した。この磁界センサは、
０．５Ｏｅの磁界を検出することができた。The incident optical waveguide 2 and the outgoing optical waveguide 5
Then, the incident optical fiber 7 and the outgoing optical fiber 8 were connected to produce a magnetic field sensor (FIG. 1). This magnetic field sensor
A magnetic field of 0.5 Oe could be detected.
【００１７】（具体的実施例２）前記具体的実施例１に
おいて、「一方の位相シフト光導波路３の１０ｍｍの長
さの部分をレーザ・アニールし、この部分を磁化反転さ
せた磁化反転部６する」を、「一方の位相シフト光導波
路３の２０ｍｍの長さの部分および他方の位相シフト光
導波路４の１０ｍｍの長さの部分をレーザ・アニール
し、これらの部分を磁化反転させて磁化反転部６，６´
を形成した」に変更した以外は前記具体的実施例１と同
様にして作製した磁界センサ（図２）は、０．５Ｏｅの
磁界を検出することができた。(Specific Embodiment 2) In the specific embodiment 1, "a part of the one phase shift optical waveguide 3 having a length of 10 mm is annealed by laser, and the magnetization reversal portion 6 is formed by reversing the magnetization. “The one part of the phase shift optical waveguide 3 having a length of 20 mm and the other part of the phase shift optical waveguide 4 having a length of 10 mm are annealed by laser, and these parts are subjected to magnetization reversal. Part 6, 6 '
The magnetic field sensor (FIG. 2) manufactured in the same manner as in the above-mentioned specific example 1 was able to detect a magnetic field of 0.5 Oe, except that the magnetic field sensor was changed to “formed.
【００１８】前記実施例では磁気複屈折効果を示す物質
としてＬａ、Ｇａ置換イットリウム・アイアン・ガーネ
ット結晶を用いたものを例として説明したが、本発明は
これのみに限定されるものではなく、磁気複屈折効果を
示す物質として他のイットリウム・アイアン・ガーネッ
ト結晶、重フリントガラス等を用いたものでもよい。ま
た、磁性体としてＮｉを用いたものを例として説明した
が、他の金属、あるいはフェライト磁性体を用いたもの
であってもよい。In the above-mentioned embodiment, the substance using the La and Ga-substituted yttrium iron garnet crystal was described as an example of the substance exhibiting the magnetic birefringence effect, but the present invention is not limited to this and the magnetic As the substance exhibiting the birefringence effect, another yttrium / iron / garnet crystal, heavy flint glass, or the like may be used. Further, although the case where Ni is used as the magnetic body has been described as an example, another metal or a ferrite magnetic body may be used.
【００１９】[0019]
【発明の効果】本発明の磁界センサは、微小な磁界を検
出することが可能となり、感度を十分に向上させること
ができる。The magnetic field sensor of the present invention can detect a minute magnetic field and can sufficiently improve the sensitivity.
【図１】本発明の第１の実施例を示す正面図である。FIG. 1 is a front view showing a first embodiment of the present invention.
【図２】本発明の第２の実施例を示す正面図である。FIG. 2 is a front view showing a second embodiment of the present invention.
１ 基板 ２ 入射光導波路 ３，４ 位相シフト光導波路 ５ 出射光導波路 ６，６´ 磁化反転部 ７ 入射光ファイバ ８ 出射光ファイバ 1 substrate 2 Incident optical waveguide 3,4 Phase shift optical waveguide 5 Output optical waveguide 6,6 'Magnetization reversal section 7 Incident optical fiber 8 Output optical fiber
Claims (2)
効果を有する入射光導波路と、前記基板に前記入射光導
波路より分岐するように形成され磁気複屈折効果を有す
る２つの位相シフト光導波路と、前記基板に前記位相シ
フト光導波路が合流するように形成され磁気複屈折効果
を有する出射光導波路とを具備し、前記位相シフト光導
波路を導波する光の位相シフトが磁気複屈折効果によっ
て生じることを利用する磁界センサにおいて、前記位相
シフト光導波路のいずれかひとつの位相シフト光導波路
の１部を、前記位相シフト光導波路のいずれかひとつの
位相シフト光導波路の残りの部分に対して、磁化反転さ
せた磁化反転部を有することを特徴とする磁界センサ。1. A substrate, an incident optical waveguide having a magnetic birefringence effect formed on the substrate, and two phase shift optical waveguides having a magnetic birefringence effect formed on the substrate so as to be branched from the incident optical waveguide. If, comprising an exit optical waveguide having a magnetic birefringence effect is formed so that the phase-shift optical waveguides on said substrate are joined, the phase shifted light guide
The phase shift of the light guided in the waveguide is caused by the magnetic birefringence effect.
In the magnetic field sensor utilizing the phenomenon that occurs , a part of any one of the phase shift optical waveguides is replaced with one of the phase shift optical waveguides .
A magnetic field sensor having a magnetization reversal portion in which the magnetization is reversed with respect to the remaining portion of the phase shift optical waveguide .
効果を有する入射光導波路と、前記基板に前記入射光導
波路より分岐するように形成され磁気複屈折効果を有す
る２つの位相シフト光導波路と、前記基板に前記位相シ
フト光導波路が合流するように形成され磁気複屈折効果
を有する出射光導波路とを具備し、前記位相シフト光導
波路を導波する光の位相シフトが磁気複屈折効果によっ
て生じることを利用する磁界センサにおいて、前記位相
シフト光導波路のそれぞれの１部を、前記位相シフト光
導波路のそれぞれの残りの部分に対して、磁化反転させ
た磁化反転部を有し、かつ、これらの磁化反転部の長さ
が異なることを特徴とする磁界センサ。2. A substrate, an incident optical waveguide having a magnetic birefringence effect formed on the substrate, and two phase shift optical waveguides having a magnetic birefringence effect formed on the substrate so as to be branched from the incident optical waveguide. If, comprising an exit optical waveguide having a magnetic birefringence effect is formed so that the phase-shift optical waveguides on said substrate are joined, the phase shifted light guide
The phase shift of the light guided in the waveguide is caused by the magnetic birefringence effect.
In the magnetic field sensor utilizing the resulting Te, each of one part of the phase-shift optical waveguides, the phase shifted light
A magnetic field sensor, characterized in that it has a magnetization reversal part in which the magnetization is reversed with respect to each of the remaining portions of the waveguide , and the lengths of these magnetization reversal parts are different.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12781794A JP3388373B2 (en) | 1994-06-09 | 1994-06-09 | Magnetic field sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12781794A JP3388373B2 (en) | 1994-06-09 | 1994-06-09 | Magnetic field sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07333306A JPH07333306A (en) | 1995-12-22 |
| JP3388373B2 true JP3388373B2 (en) | 2003-03-17 |
Family
ID=14969403
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12781794A Expired - Fee Related JP3388373B2 (en) | 1994-06-09 | 1994-06-09 | Magnetic field sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3388373B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4044030B2 (en) * | 2003-11-27 | 2008-02-06 | 独立行政法人産業技術総合研究所 | Magnetic sensor device |
-
1994
- 1994-06-09 JP JP12781794A patent/JP3388373B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07333306A (en) | 1995-12-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ignatyeva et al. | All-dielectric magnetic metasurface for advanced light control in dual polarizations combined with high-Q resonances | |
| US5736856A (en) | Method and apparatus for performing magnetic field measurements using magneto-optic Kerr effect sensors | |
| US7254286B2 (en) | Magneto-optical resonant waveguide sensors | |
| Shintaku et al. | Magneto‐optic channel waveguides in Ce‐substituted yttrium iron garnet | |
| US5408565A (en) | Thin-film magneto-optic polarization rotator | |
| US5625284A (en) | Electric field sensor having sensor head with unbalanced electric field shield to shield branched optical waveguides against an applied electric field | |
| US5689391A (en) | Magneto-optic multitrack reading head having a plurality of reflective rays | |
| NL8302585A (en) | MAGNETIC HEAD. | |
| JPWO2010023738A1 (en) | Optical nonreciprocal element manufacturing method and optical nonreciprocal element | |
| JPH02293680A (en) | Magnetic field detector | |
| US6943932B2 (en) | Waveguide mach-zehnder optical isolator utilizing transverse magneto-optical phase shift | |
| JP3388373B2 (en) | Magnetic field sensor | |
| JPH03288104A (en) | Unidirectional mode converter and optical isolator using the same | |
| Levy et al. | Permanent magnet film magneto‐optic waveguide isolator | |
| JP3521366B2 (en) | Branch interference optical waveguide type magnetic field sensor | |
| RU161388U1 (en) | MAGNETO-OPTICAL LIGHT INTENSITY MODULATOR | |
| Wolfe et al. | Fiber optic magnetic field sensor based on domain wall motion in garnet film waveguides | |
| JP3388371B2 (en) | Branch interference optical waveguide type magnetic field sensor | |
| JP2005099737A (en) | Magnetooptic optical component | |
| CN101949969A (en) | Sensing head of optical current transformer and sensing method | |
| JPH07209395A (en) | Optical magnetic field sensor | |
| RU205928U1 (en) | Magneto-optical sensor | |
| CN109669065A (en) | The voltage measurement method realized based on bar shaped radial polarisation grating | |
| JP2004219137A (en) | Reflection type optical magnetic field sensor head | |
| JP3130131B2 (en) | Optical isolator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20021211 |
|
| LAPS | Cancellation because of no payment of annual fees |