JPH0495919A - Magnetic field application structure of magnetooptic element - Google Patents
Magnetic field application structure of magnetooptic elementInfo
- Publication number
- JPH0495919A JPH0495919A JP20806090A JP20806090A JPH0495919A JP H0495919 A JPH0495919 A JP H0495919A JP 20806090 A JP20806090 A JP 20806090A JP 20806090 A JP20806090 A JP 20806090A JP H0495919 A JPH0495919 A JP H0495919A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- current
- magneto
- optical
- ferromagnetic material
- 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
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 31
- 230000003287 optical effect Effects 0.000 claims abstract description 20
- 239000010408 film Substances 0.000 claims description 21
- 230000005294 ferromagnetic effect Effects 0.000 claims description 19
- 239000010409 thin film Substances 0.000 claims description 5
- 238000005253 cladding Methods 0.000 claims description 4
- 239000003302 ferromagnetic material Substances 0.000 abstract 4
- 230000005389 magnetism Effects 0.000 abstract 1
- 230000005415 magnetization Effects 0.000 description 6
- 239000000758 substrate Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- ZPDRQAVGXHVGTB-UHFFFAOYSA-N gallium;gadolinium(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Ga+3].[Gd+3] ZPDRQAVGXHVGTB-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- QXZUUHYBWMWJHK-UHFFFAOYSA-N [Co].[Ni] Chemical compound [Co].[Ni] QXZUUHYBWMWJHK-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000002223 garnet Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明しＬ磁気光学素子においてプレーナ光波回路に適
合した磁界印加構造に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic field applying structure suitable for a planar light wave circuit in an L magneto-optical element.
（従来の技術）
光アイソレータ、光サーキュレータ等の磁気光学素子は
、ファラデー効果などの磁界により屈折率が変化する現
象を利用した素子で、光の伝搬特性に非相反性を有する
という特徴がある。このため、例えば光アイソレータは
、レーザへの反射戻り光を除くための素子として多用さ
れている。各種の光デバイスの集積回路化が進むなかで
、光アイソレータ等の非相反光素子についても集積回路
化の要求が高まり、このため、１枚の基板上に形成する
、プレーナ光波回路型の光アイソレータまたは光サーキ
ュレータ等の開発が進められている。(Prior Art) Magneto-optical elements such as optical isolators and optical circulators are elements that utilize a phenomenon in which the refractive index changes due to a magnetic field, such as the Faraday effect, and are characterized by having non-reciprocal light propagation characteristics. For this reason, optical isolators, for example, are frequently used as elements for eliminating reflected light returning to the laser. As the integration of various optical devices progresses, the demand for integrated circuits of non-reciprocal optical elements such as optical isolators is increasing, and for this reason, planar light wave circuit type optical isolators that are formed on a single substrate are being developed. Alternatively, optical circulators and the like are being developed.
プレーナ光波回路型の磁気光学素子を実現するにあたっ
て、磁界の印加方法は重要な課題であるが、十分な技術
検討は行われていない。従来は、微少な磁石を素子基板
に接近して取り付ける方法、または素子基板の上に導体
線を設けて、この導体線に直流電流を流すことにより磁
界を印加する等の方法が提案されている。しかし、前者
の方法は小型化には適していないうえ、印加磁界の方位
を精密に設定することが難しく、一方、後者の方法は、
強い磁界を印加することができないこと、電流を常に流
しておく必要があるため電力を消費し、かつ外部に電源
を必要とする等の問題がある。In realizing a planar light wave circuit type magneto-optical element, the method of applying a magnetic field is an important issue, but sufficient technical studies have not been conducted. Conventionally, methods have been proposed, such as attaching a minute magnet close to the element substrate, or providing a conductor wire on the element substrate and applying a magnetic field by passing a direct current through the conductor wire. . However, the former method is not suitable for miniaturization, and it is difficult to precisely set the direction of the applied magnetic field.
There are problems such as the inability to apply a strong magnetic field, the need to keep current flowing, which consumes power, and requires an external power source.
（発明が解決しようとする課題）
本発明は前述の従来の技術における問題点を解決し、プ
レーナ光波回路に適合し、簡単な構成で所要の磁界を印
加することが可能な磁気光学素子の磁界印加構造を提供
することにある。(Problems to be Solved by the Invention) The present invention solves the problems in the conventional techniques described above, and provides a magnetic field for a magneto-optical element that is compatible with a planar light wave circuit and is capable of applying a required magnetic field with a simple configuration. The purpose is to provide an application structure.
（課題を解決するための手段）
本発明の磁気光学素子の磁界印加構造は、磁気光学薄膜
を光導波路の構成要素とするプレーナ光波回路型磁気光
学素子に、磁界を印加する構造であって、前記光導波路
の上部にクラッド層を介して、強磁性体膜と該強磁性体
膜を磁化する手段を形成する。(Means for Solving the Problems) A magnetic field applying structure of a magneto-optical element of the present invention is a structure for applying a magnetic field to a planar light wave circuit type magneto-optical element having a magneto-optic thin film as a component of an optical waveguide, comprising: A ferromagnetic film and means for magnetizing the ferromagnetic film are formed above the optical waveguide via a cladding layer.
すなわち磁気光学素子を構成する基板の上に、真空蒸着
、スパッタリングまたはメツキ等の方法で形成した強磁
性体膜を、電流印加または外部磁石で磁化し、このよう
にして磁化された強磁性体膜により生じる磁界を、素子
に印加する。In other words, a ferromagnetic film formed on a substrate constituting a magneto-optical element by a method such as vacuum evaporation, sputtering, or plating is magnetized by applying a current or using an external magnet, and the ferromagnetic film magnetized in this way is A magnetic field generated by this is applied to the element.
このような構造であるので、前記強磁性体膜を−たん磁
化した後は、外部磁石または磁界発生のための電流を印
加する必要がないので、小型化が容易で、他のプレーナ
光波回路素子との適合性が良く、また素子の消費電力を
なくすこともできる。With this structure, after the ferromagnetic film is temporarily magnetized, there is no need to apply an external magnet or a current for generating a magnetic field, so it is easy to downsize and can be used with other planar light wave circuit elements. It has good compatibility with the device and can also eliminate the power consumption of the device.
（実施例）
第１図は、本発明による磁気光学素子の磁界印加構造の
一実施例を示し、（ａ）は平面図、（ｂ）はＡ−Ａ′に
おける断面図である。第１図において、１はガドリニウ
ムガリウムガーネット（ＧＧＧ）基板、２ａ、 ２ｂは
磁気光学効果を有する鉄ガーネットで形成した先導波路
（以下、磁気光学導波路または単に導波路という。）、
３はクラッド層、４ａ４ｂは強磁性体膜、５ａ、 ５ｂ
は電極、Ｐ＋、Ｐｚは電極に電流を印加するための端子
である。導波路２ａと導波路２ｂは図に示すように、記
号Ｃで示す部分において接近して平行に設けられており
、この部分は光の方向性結合器となっている。さらに、
強磁性体膜４ａおよび４ｂは、それぞれ方向性結合器部
分、すなわち領域Ｃの部分においてクラッド層３を介し
て導波路２ａおよび２ｂの上方部に配置されている。(Example) FIG. 1 shows an example of a magnetic field application structure of a magneto-optical element according to the present invention, in which (a) is a plan view and (b) is a cross-sectional view taken along line A-A'. In FIG. 1, 1 is a gadolinium gallium garnet (GGG) substrate, 2a and 2b are guide waveguides (hereinafter referred to as magneto-optic waveguides or simply waveguides) formed of iron garnet having a magneto-optic effect;
3 is a cladding layer, 4a4b is a ferromagnetic film, 5a, 5b
is an electrode, and P+ and Pz are terminals for applying current to the electrode. As shown in the figure, the waveguide 2a and the waveguide 2b are provided close to each other in parallel at a portion indicated by symbol C, and this portion serves as a directional coupler for light. moreover,
The ferromagnetic films 4a and 4b are arranged above the waveguides 2a and 2b via the cladding layer 3 in the directional coupler portion, that is, the region C portion, respectively.
この実施例における動作を以下に説明する。まず、第１
図に示す構成の素子において、５ａ、 ５ｂからなる電
極の両端部Ｐ、Ｐ２に外部電源を接続して短時間、直流
電流ｉを流した後、電流を遮断する。The operation in this embodiment will be explained below. First, the first
In the element having the configuration shown in the figure, an external power source is connected to both ends P and P2 of the electrodes 5a and 5b, and after a direct current i is passed for a short time, the current is cut off.
電流によって発生した磁界によって、強磁性体膜４ａお
よび４ｂは磁化され、電流遮断後も磁化は保持される。The ferromagnetic films 4a and 4b are magnetized by the magnetic field generated by the current, and the magnetization is maintained even after the current is cut off.
第２図はこのようにして磁化された後の磁力線の分布の
様子を磁気光学素子の印加構造の断面図を用いて示す。FIG. 2 shows the distribution of lines of magnetic force after magnetization in this manner using a cross-sectional view of the application structure of the magneto-optical element.
電流の方向は４ａ部分と４ｂ部分とで逆向きになってい
るから、磁化される方向も記号ＭおよびＭ′を付した矢
印で示すように相互に反対向きになる。強磁性体膜から
出る磁力線は、光導波路をよぎるので、図に示すように
導波路２ａと２ｂとでは互いに反対向きの磁界が印加さ
れることになる。Since the direction of the current is opposite between the portions 4a and 4b, the directions of magnetization are also opposite to each other, as shown by the arrows marked M and M'. Since the magnetic lines of force coming out of the ferromagnetic film cross the optical waveguide, magnetic fields in opposite directions are applied to the waveguides 2a and 2b, as shown in the figure.
光導波路２ａおよび２ｂは磁気光学効果のある先導波路
であるから、前述のように磁界が印加されることにより
、前進波と後進波との伝搬速度が異なるようになり、領
域Ｃ（方向性結合器）の結合特性は前進波と後進波に対
して異なった特性が得られ、非相反性の方向性結合器と
なる。その結果、光サーキュレータとして動作する（特
願平１−１４５４４６号参照）。Since the optical waveguides 2a and 2b are leading waveguides with a magneto-optic effect, by applying a magnetic field as described above, the propagation speeds of the forward wave and the backward wave become different, resulting in region C (directional coupling). The coupling characteristics of the device are different for forward waves and backward waves, making it a non-reciprocal directional coupler. As a result, it operates as an optical circulator (see Japanese Patent Application No. 1-145446).
前述のように、本発明の磁界印加構造では、強磁性体膜
を磁化させるときのみ電流を印加するものであるから、
通常の使用時には電流を流す必要がない。また電流の印
加方向を逆転させれば、磁化の方向も逆転するから、サ
ーキュレータの特性を反転させることができるので、自
己保持型の光スィッチとして使用することも可能である
。As mentioned above, in the magnetic field application structure of the present invention, current is applied only when magnetizing the ferromagnetic film.
No current needs to flow during normal use. Furthermore, if the direction of current application is reversed, the direction of magnetization is also reversed, so the characteristics of the circulator can be reversed, so it can also be used as a self-holding optical switch.
強磁性体膜はスパッタリング等の薄膜技術によって形成
できるから、第１図の構成はプレーナ光波回路に適して
いる。また強磁性体薄膜は、薄膜磁気ヘッドなどで用い
られているように、磁化容易方向を面内にすることが可
能であり、その場合、磁化するために必要な印加電流は
高々数十ｍＡでよい。Since the ferromagnetic film can be formed by a thin film technique such as sputtering, the configuration shown in FIG. 1 is suitable for a planar light wave circuit. In addition, ferromagnetic thin films can be easily magnetized in-plane, as used in thin-film magnetic heads, and in that case, the applied current required for magnetization is several tens of mA at most. good.
なお強磁性体膜の材料としては、フェライトのような金
属酸化膜またはニッケルーコバルトのような合金膜を用
いてもよいが、導電性が大きい材料の場合には、強磁性
体膜と電極との間に適当な絶縁膜を設ければ前記動作に
は支障はない。As the material for the ferromagnetic film, a metal oxide film such as ferrite or an alloy film such as nickel-cobalt may be used, but in the case of a material with high conductivity, the ferromagnetic film and the electrode may be used. If an appropriate insulating film is provided between them, there will be no problem with the above operation.
第３図は、本発明の他の実施例図であり、第２図とは電
極と強磁性体膜の形成順序が逆に成っているが、動作は
同様である。FIG. 3 is a diagram showing another embodiment of the present invention, in which the order of forming the electrodes and the ferromagnetic film is reversed from that in FIG. 2, but the operation is the same.
（発明の効果）
以上説明したように、本発明による磁気光学素子の磁界
印加構造は、簡単な構成で所要の磁界を印加することが
可能であり、−たん磁化操作を行った後は、電流印加を
必要としないなどの特徴があり、光素子のプレーナ光波
回路化に有効である。(Effects of the Invention) As explained above, the magnetic field application structure of the magneto-optical element according to the present invention can apply a required magnetic field with a simple configuration, and after performing the magnetization operation, the current It has features such as not requiring any voltage, and is effective for converting optical devices into planar light wave circuits.
第１図は本発明の一実施例を示し、（ａ）は平面図、（
ｂ）は第１図（ａ）のＡ−Ａ’ における断面図、第２
図は磁界の分布を示す図、
第３図は本発明の他の実施例を示す図である。
１・・・基板 ２ａ、 ２ｂ・・・光導波
路３・・・クラッド層 ４ａ、 ４ｂ・・・強磁
性体膜５ａ、 ５ｂ・・・電極
第１図
（ａ）
（ｂ）FIG. 1 shows an embodiment of the present invention, in which (a) is a plan view and (a) is a plan view;
b) is a sectional view taken along line AA' in Fig. 1(a);
The figure shows the distribution of a magnetic field, and FIG. 3 is a diagram showing another embodiment of the present invention. 1... Substrate 2a, 2b... Optical waveguide 3... Clad layer 4a, 4b... Ferromagnetic film 5a, 5b... Electrode Fig. 1 (a) (b)
Claims (1)
光波回路型磁気光学素子に磁界を印加するための構造で
あって、前記光導波路の上部にクラッド層を介して、強
磁性体膜と該強磁性体膜を磁化する手段が形成されてい
ることを特徴とする磁気光学素子の磁界印加構造。 ２、前記強磁性体膜を磁化する手段が磁界発生用電極で
あることを特徴とする請求項１に記載の磁気光学素子の
磁界印加構造。[Scope of Claims] 1. A structure for applying a magnetic field to a planar optical wave circuit type magneto-optical element having a magneto-optic thin film as a component of an optical waveguide, the structure comprising: a cladding layer provided above the optical waveguide; A magnetic field application structure for a magneto-optical element, comprising a ferromagnetic film and a means for magnetizing the ferromagnetic film. 2. The magnetic field application structure of a magneto-optical element according to claim 1, wherein the means for magnetizing the ferromagnetic film is a magnetic field generating electrode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20806090A JPH0495919A (en) | 1990-08-08 | 1990-08-08 | Magnetic field application structure of magnetooptic element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20806090A JPH0495919A (en) | 1990-08-08 | 1990-08-08 | Magnetic field application structure of magnetooptic element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0495919A true JPH0495919A (en) | 1992-03-27 |
Family
ID=16549978
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20806090A Pending JPH0495919A (en) | 1990-08-08 | 1990-08-08 | Magnetic field application structure of magnetooptic element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0495919A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0685081A1 (en) * | 1993-02-22 | 1995-12-06 | The Trustees of Columbia University in the City of New York | Thin-film magneto-optic polarization rotator |
-
1990
- 1990-08-08 JP JP20806090A patent/JPH0495919A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0685081A1 (en) * | 1993-02-22 | 1995-12-06 | The Trustees of Columbia University in the City of New York | Thin-film magneto-optic polarization rotator |
| EP0685081A4 (en) * | 1993-02-22 | 1996-12-18 | Univ Columbia | Thin-film magneto-optic polarization rotator. |
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