JPS58173703A - Production of optical isolator - Google Patents

Abstract

PURPOSE:To provide an optical isolator which is small in size and has a good operation characteristic, by growing a crystal in such a way that an anisotropic crystal and a thin film of a magnetooptic crystal adheres tightly to each other and sandwiching said thin film between an isotropic crystal and the anisotropic crystal thereby manufacturing the optical isolator. CONSTITUTION:A thin film 22 of a magnetooptic crystal having the same garnet structure as the structure of an isotropic crystal 21 such as Gd3Ga5O3(GGG) crystal or the like, such as Y3F5O12(YIG) crystal is formed on the crystal 21. Since an anisotropic crystal 23 such as LiNbO3 is a trigonal crystal and differs considerably in lattice constant from the YIG crystal, a flux such as LiVO3 is coated in a lattice shape on the film 22; thereafter, the crystal 23 is grown to form the crystal 23 on the film 22. Thin metallic films 24, 24 are formed on the film 22 on both sides of the crystal 23, whereby an optical isolator is obtained. Or the crystal 23 is grown after a lattice-like groove is formed on the film 22 or an amorphous layer of SiO2 or the like is formed thereon. The adhesion between the film 22 and the film 23 is thus improved and the operation characteristic is improved.

Description

【発明の詳細な説明】 〔発明の技術分野〕 本発明は光アイソレータの製造方法に関する。[Detailed description of the invention] [Technical field of invention] The present invention relates to a method for manufacturing an optical isolator.

〔発明の技術的背景とその問題点〕[Technical background of the invention and its problems]

光アイソレータは反射防止、半導体レーデの安定等に必
要不可欠のものである。ががる光アイソレータとしては
、従来、第１図に示す如く偏光子１と、磁気光学４５°
回転子２と、前記偏光子１に対して主軸を４５＠傾けた
検光子３とからなるバルク形のものが知られている。な
お、図中４は透過光を、５は磁界方向を示す。しかしな
がら、こうしたバルク形光アイソレータは各素子が数１
角の大きさである丸め、大形化になネという欠点があっ
た。Optical isolators are essential for preventing reflections and stabilizing semiconductor radars. Conventionally, as shown in FIG.
A bulk type device is known, which consists of a rotor 2 and an analyzer 3 whose main axis is inclined by 45 degrees with respect to the polarizer 1. In the figure, 4 indicates the transmitted light, and 5 indicates the direction of the magnetic field. However, in such bulk type optical isolators, each element has a number of
The disadvantage was that the corners were too rounded and too large.

このような仁とから、半導体レーザメー合や光集積回路
への組込みのた衿に小形の導波形光アイソレータが開発
されている。かがる導波形光アイソレータには以下に示
す２種のものが提案されている。In response to this trend, small-sized waveguide optical isolators have been developed for use in semiconductor laser automation and incorporation into optical integrated circuits. The following two types of waveguide optical isolators have been proposed.

マス、一つの導波形光アイツレ−／ｌ［２図に示す如く
等方性結晶６上に磁気光学結晶薄膜１及び等方性媒質Ｉ
を順次積層し、かつ等方性媒質８両端の磁気光学結晶薄
膜１上に金属薄膜９．９を設けた構造を有し、磁界方向
１０．１１により前記等方性結晶６、磁気光学結晶薄膜
７及び勢方性媒質８を積層方向に非相反部１２、相反部
１３に区別している。前記非相反部１２では磁気光学結
晶薄膜７のファラデー効果、相反部１３ではコツトン・
ムートン効果を利用している。かかる光アイソレータは
等方性媒質８を空気層で代用することができ、実際には
等方性結晶−と磁気光学結晶薄膜７の２層のみで動作が
可能であるという利点を有する。しかしながら、相反部
ｉｓ　６ｃ必要な磁界は２５０００程度で非相反部／２
で必要とする１５θ＠の磁界に比べて桁違いに大きいた
め、第２図中に示されていない大形の磁石を必要とし、
光アイソレータの小形化を実際上達成できない。mass, one waveguide optical Eitzley/l [As shown in Figure 2, a magneto-optic crystal thin film 1 and an isotropic medium I are placed on an isotropic crystal 6.
It has a structure in which a metal thin film 9.9 is provided on the magneto-optic crystal thin film 1 on both ends of the isotropic medium 8, and the isotropic crystal 6 and the magneto-optic crystal thin film are stacked in order according to the magnetic field direction 10.11. 7 and the orientational medium 8 are divided into a non-reciprocal portion 12 and a reciprocal portion 13 in the stacking direction. In the non-reciprocal part 12, the Faraday effect of the magneto-optic crystal thin film 7 occurs, and in the reciprocal part 13, the Cotton effect occurs.
It uses the Mouton effect. Such an optical isolator has the advantage that the isotropic medium 8 can be replaced with an air layer, and that it can actually operate with only two layers, the isotropic crystal and the magneto-optic crystal thin film 7. However, the required magnetic field for the reciprocal part is 6c is about 25,000, and the non-reciprocal part/2
Since it is an order of magnitude larger than the 15θ@ magnetic field required in
It is practically impossible to downsize the optical isolator.

一方、もう一つの導波形光アイソレータは第３図に示す
如く、等方性結晶ｄ上に磁気光学結晶薄膜７と異方性結
晶１４を順次積層した構造に表っている。この光アイソ
レータは相反部、非相反部が合体しており、光線方向に
平行な単一磁界１５のみで動作する。したがって、磁界
の強さは比較的小さくてすむので、小形化が可能であり
、実現が望まれている。しかしながら、かかる構造の光
アイソレータで導波路を形成すると、磁気光学結晶薄膜
１と異方性結晶１４の間に空気層が介在し、密着性が劣
るため、光アイソレータの動作は未だ確認していない。On the other hand, another waveguide type optical isolator has a structure in which a magneto-optic crystal thin film 7 and an anisotropic crystal 14 are sequentially laminated on an isotropic crystal d, as shown in FIG. This optical isolator has a reciprocal part and a non-reciprocal part combined, and operates only with a single magnetic field 15 parallel to the direction of the light beam. Therefore, since the strength of the magnetic field only needs to be relatively small, miniaturization is possible, and realization is desired. However, when a waveguide is formed using an optical isolator with such a structure, an air layer is interposed between the magneto-optic crystal thin film 1 and the anisotropic crystal 14, resulting in poor adhesion, so the operation of the optical isolator has not yet been confirmed. .

〔発明の目的〕[Purpose of the invention]

本発明は喪好な動作特性を有すると共に小形化を実現し
得る光アイソレータの製造方法を提供しようとするもの
である。The present invention aims to provide a method for manufacturing an optical isolator that has favorable operating characteristics and can be made compact.

〔発明の概要〕[Summary of the invention]

本発明は等方性結晶と異方性結晶とで磁気光学結晶薄膜
を挾んだサンドイッチ構造を有する光アイソレータの製
造において、等方性結晶上に順次磁気光学結晶薄膜と異
方性結晶を、或いは異方性結晶上に順次磁気光学結晶薄
膜と等方性結晶を、該ａ気元学ＭＪ＆薄膜と異方性結晶
とが良好に密着するように成長せしめることを特徴とす
るものである。The present invention relates to manufacturing an optical isolator having a sandwich structure in which a magneto-optic crystal thin film is sandwiched between an isotropic crystal and an anisotropic crystal, in which a magneto-optic crystal thin film and an anisotropic crystal are sequentially placed on an isotropic crystal. Alternatively, it is characterized in that a magneto-optic crystal thin film and an isotropic crystal are sequentially grown on an anisotropic crystal such that the a-magnetic MJ& thin film and the anisotropic crystal are in good contact with each other.

〔発明の実施例〕[Embodiments of the invention]

次に、本発明の実施例を図面を参照して説明する。 Next, embodiments of the present invention will be described with reference to the drawings.

実施例１ まず、例えばＱｄ５Ｇａ５０３　（ＧＧＧ　）結晶から
表る等方性結晶２１上に例えばＹＩＧ　（Ｙ３Ｆ５０１
２）結晶からなる磁気光学結晶薄膜２２を成長させた。Example 1 First, for example, YIG (Y3F501
2) A magneto-optic crystal thin film 22 made of crystal was grown.

この時、等方性結晶２１を磁気光学結晶薄膜２２と構造
の類偏したものを選ぶことにより等方性結晶２１上゛に
密着性よく磁気光学結晶薄膜２２を成長できる０例えば
、ＧＧＧ結晶とＹＩＧ結晶は共にガーネット構造を有し
ており、前者の格子定数は１２．３８３Ｘ、後者はそれ
は１２゜３７６Ｘと近接しているため、整合性は非常に
よい。At this time, by selecting the isotropic crystal 21 having a structure similar to that of the magneto-optic crystal thin film 22, the magneto-optic crystal thin film 22 can be grown on the isotropic crystal 21 with good adhesion. Both YIG crystals have a garnet structure, and the former has a lattice constant of 12.383X, while the latter has a lattice constant of 12°376X, which are close to each other, so the matching is very good.

次いで、ＹＩＧ結晶から表る磁気光学結晶薄膜２２上に
例えばＬｉＮｂＯ５からなる異方性結晶を成長させる。Next, an anisotropic crystal made of, for example, LiNbO5 is grown on the magneto-optic crystal thin film 22 exposed from the YIG crystal.

ここでＹ■Ｇ結晶は立方晶に属する結晶であるのに対し
ＬｉＮｂＯ５は三方晶であシ、結晶構造が異なる上、Ｌ
ｉＮｂＯ５の格子定数はｍ＝５．１４８Ｘ　。Here, the Y■G crystal is a crystal belonging to the cubic crystal, whereas the LiNbO5 is a trigonal crystal, and the crystal structure is different, and the L
The lattice constant of iNbO5 is m=5.148X.

ｅ＝１３．８６３１とＹＩＧ結晶の格子定数とは大きく
異なるため、ＹＩＧ結晶からなる磁気光学結晶薄膜上に
ＬＩＮｂＯｓからなる異方性結晶を整合性（密着性）よ
く成長することは通常困難である。Since e=13.8631 is significantly different from the lattice constant of YIG crystal, it is usually difficult to grow an anisotropic crystal made of LINbOs with good consistency (adhesion) on a magneto-optic crystal thin film made of YIG crystal. .

そこでＹＩＧ結晶からなる磁気光学結晶薄膜２２上に例
えばＬ　Ｉ　ＶＯ５の７ラツクス（図示せず）を７格子
状に塗布した後、ＬＳ　ＮｂＯ５を成長させた。この時
、格子状のフラ、クス部分から選択的にＬＩＮｂＯｓの
結晶化が始ｔｂ、フラックス形状の周期の影響で磁気光
学結晶薄膜２２上Ｋ　ＬＩＮｂＯｓの異方性結晶２３が
成長された。なお、異方性結晶として用い九ＬＩＮｂＯ
ｓの融点は１２６０°前後であるが、ｔ、ｔｖｏ３のフ
ラックスを用いることにより、８００°Ｃ前後の低温で
の結晶成長が可能となる。その後、異方性結晶２３両端
側の磁気光学結晶薄膜２２上に金属薄膜：１４．２４を
前記異方性結晶２３に対して恵望距離はなして形成１７
光アイソレータを製造した（第４図図示）。Therefore, for example, 7 luxes (not shown) of LIVO5 were applied in a 7-lattice pattern on the magneto-optic crystal thin film 22 made of YIG crystal, and then LS NbO5 was grown. At this time, crystallization of LINbOs started selectively from the lattice-shaped flux portions, and an anisotropic crystal 23 of KLINbOs was grown on the magneto-optic crystal thin film 22 due to the influence of the period of the flux shape. In addition, nine LINbO used as an anisotropic crystal.
The melting point of s is around 1260°, but by using fluxes of t and tvo3, crystal growth at a low temperature of around 800°C becomes possible. Thereafter, metal thin films 14 and 24 are formed on the magneto-optic crystal thin film 22 on both end sides of the anisotropic crystal 23 at a distance 17 from the anisotropic crystal 23.
An optical isolator was manufactured (as shown in FIG. 4).

なお、第４図中の２５は光透過順方向を、２６は磁界方
向を示すものである。Note that 25 in FIG. 4 indicates the forward direction of light transmission, and 26 indicates the direction of the magnetic field.

実施例２ まず、実施例１と同様ＧＧＧ結晶からなる等、方性結晶
２１上Ｋ　ＹＩＧ結晶からなる磁気光学結晶薄膜２２を
成長させ丸後、該薄膜２２表面に深さ０．１ａｍ、幅０
．１μ溝、♂フチ３μ慣の格子状の溝２１を通常のフォ
トエツチング技術によ多形成した。Example 2 First, as in Example 1, a magneto-optic crystal thin film 22 made of KYIG crystal, such as made of GGG crystal, was grown on an oriented crystal 21, and then a layer was formed on the surface of the thin film 22 to a depth of 0.1 am and a width of 0.
．． A grid-like groove 21 with a 1μ groove and a 3μ square edge was formed using a conventional photoetching technique.

次いで格子状の＃１Ｉ２１を形成した磁気光学結晶薄膜
２２上Ｋ　ＬｉＮｂＯｘをグラフオエピタキシーの技術
によシ結晶成長させることによｆｉ　ＬｉＮｂＯ３から
なる異方性結晶２３′を成長させた。その後実施例１と
同様金属薄膜２４．；１４を形成して光アイソレータを
製造した（第５図図示）。Next, the anisotropic crystal 23' of fi LiNbO3 was grown by crystal-growing the KLiNbOx on the magneto-optic crystal thin film 22 on which #1I21 was formed in the form of a lattice by graphoepitaxy. Thereafter, as in Example 1, a metal thin film 24. ; 14 was formed to manufacture an optical isolator (as shown in FIG. 5).

しかして、上記実施例１及び２によれば磁気光学結晶と
構造が類似した異方性結晶を選定すると共に１磁気光学
結晶薄膜上に格子状の７ラツクス、或いは同薄膜表面に
格子状の溝を形成することＫよって、磁気光学結晶薄膜
上に異方性結晶を直接成長させることができる。このよ
うに製造された等方性結晶２１と異方性結晶２３とで磁
気光学結晶薄膜２２を挾んだサンドイッチ構造の導波形
光アイソレータは各層間の密着性に優れ、光アイソレー
タとして良好な特性を有する。According to Examples 1 and 2, an anisotropic crystal similar in structure to the magneto-optic crystal is selected, and seven lattice-like grooves are formed on one magneto-optic crystal thin film, or lattice-like grooves are formed on the surface of the same thin film. By forming K, an anisotropic crystal can be directly grown on a magneto-optic crystal thin film. The waveguide optical isolator having a sandwich structure in which the magneto-optic crystal thin film 22 is sandwiched between the isotropic crystal 21 and the anisotropic crystal 23 produced in this way has excellent adhesion between each layer and has good characteristics as an optical isolator. has.

実施例３ 実施例１と同様、ＧＧＧ結晶からなる等方性結晶２１上
にＹＩＧ結晶からなる磁気光学結晶薄膜２２を成長させ
た後、該薄膜２２上Ｋ例えば５ｉ０２からなる非晶質薄
膜２８を蒸着した。Example 3 As in Example 1, after growing a magneto-optic crystal thin film 22 made of YIG crystal on an isotropic crystal 21 made of GGG crystal, an amorphous thin film 28 made of, for example, 5i02, is grown on the thin film 22. Deposited.

次いで、前記非晶質薄膜２８上にＬｉＮｂＯｘを成長さ
せた。この時、ＹＩＧ結晶とＬ　Ｉ　Ｎｂ　Ｏ５の間に
非晶質薄膜２８を挾むことにより、前述したそれらＹＩ
Ｇ結晶とＬＩＮｂＯｓの結晶構造の不一致が遮蔽され、
Ｌｉ　Ｎｂ　Ｏｓ単結晶からなる異方性結晶２Ｉを容易
に成長できた。なお、前記非晶質薄膜２８の厚さは上下
の結晶境界面の相互作用を遮蔽するに十分な厚さで、か
つＹＩＧ結晶からなる磁気光学結晶薄膜内を伝播する光
の電磁界がＬｉＮｂＯ３結晶と相互作用するに十分なだ
け薄くする必要がある。一般に、結晶構造の格子定数と
同程度（〜ｌ０Ｘ）までしか及ばないが、光の相互作用
は光の波長１度（〜１μ惰）まで及ぶから、非晶質薄膜
２８の厚さを１００〜１０００芙程度に選べば上記効果
を十分達成できる。また、ＧＧＧ。Next, LiNbOx was grown on the amorphous thin film 28. At this time, by sandwiching the amorphous thin film 28 between the YIG crystal and L I Nb O5, the above-mentioned YI
The mismatch between the crystal structures of G crystal and LINbOs is masked,
Anisotropic crystal 2I consisting of Li Nb Os single crystal could be easily grown. The thickness of the amorphous thin film 28 is sufficient to shield the interaction between the upper and lower crystal boundary surfaces, and the electromagnetic field of light propagating within the magneto-optic crystal thin film made of YIG crystal is It needs to be thin enough to interact with the In general, the lattice constant of the crystal structure extends only to the same extent (~l0X), but since the interaction of light extends to the wavelength of light of 1 degree (~1μ), the thickness of the amorphous thin film 28 is set to 100~ The above effect can be sufficiently achieved by selecting about 1000 bushes. Also, GGG.

ＹＩＧ　、　８１０２　、　ＬｉＮｂＯ３の屈折率をｆ
ｌｇ　ｅ　Ｉｌｙ　＊　０６ｍ１１Ｌとすれば、例えば
波長６３３ｎｍの光に対してｗｓ、　＝１．９　Ｓ　ｅ
　ｔ＋ｙ＝＝２．３１　＋　１１．＝１．４６　ｒ聰、
＝２．２９（常光）、２．２０（異常光）であシ、ｍｙ
　＞　ＩＳＬ　＞　ｎｇ　＊　Ｂｙ　＞−の関係がある
。このような条件では光は最大屈折率をもつＹＩＧ内に
とらえられ、減衰することなく磁気光学結晶薄膜中を伝
播する。その後、実施例１と同様に金属薄膜２４．：１
４を形成して光アイソレータを製造した（第６図図示）
。The refractive index of YIG, 8102, LiNbO3 is f
If lg e Ily * 06m11L, for example, ws for light with a wavelength of 633 nm, = 1.9 S e
t+y==2.31+11. =1.46 r,
= 2.29 (ordinary light), 2.20 (abnormal light), my
There is a relationship of >ISL>ng*By>-. Under these conditions, light is captured in YIG, which has the maximum refractive index, and propagates through the magneto-optic crystal thin film without attenuation. Thereafter, as in Example 1, the metal thin film 24. :1
4 was formed to manufacture an optical isolator (as shown in Figure 6).
.

しかして、実施例３によれば磁気光学結晶薄膜２２上に
非晶質薄膜２８を蒸着し、この上に異方性結晶２ｙを成
長させることＫよシ、光学接着では達成できなかった密
着性を確保できる。According to Example 3, the amorphous thin film 28 is deposited on the magneto-optic crystal thin film 22, and the anisotropic crystal 2y is grown thereon, thereby achieving adhesion that could not be achieved by optical bonding. can be secured.

なお、上記実施例３において非晶質薄膜２８上に異方性
結晶２３“を成長させるに際し、非晶質薄膜表面に１次
元的又は２次元的に格子状の溝を形成することにより、
ＬＩＮｂＯ，単結晶を賓易に成長させてもよい。また、
非晶質薄膜上に１次元的又は２次元的にフラックスを形
成することによ、り　ＬＩＮｂＯｓ単Ｐ晶の成長を容易
に行なわせるようＫしてもよい。In addition, when growing the anisotropic crystal 23'' on the amorphous thin film 28 in the above Example 3, by forming lattice-like grooves one-dimensionally or two-dimensionally on the surface of the amorphous thin film,
LINbO, single crystals may be grown in a convenient manner. Also,
A flux may be formed one-dimensionally or two-dimensionally on the amorphous thin film to facilitate the growth of LINbOs single P crystal.

また、上記実施例では等方性結晶としてＧＧＧ結晶を、
磁気光学結晶膜としてＹＩＧを、異方性結晶としてＬ　
ｉ　Ｎｂ　ＯＳを、夫々用いたが、これに限定されない
。例えば轡方性結晶としてＹＩＧと同族の結晶、磁気光
学結晶薄膜としてＹ（イツトリウム）を他の希土類元素
で置換して結晶を、異方性結晶としてＬＩＴａＯｓを、
夫々用いてもよい。In addition, in the above example, a GGG crystal is used as an isotropic crystal.
YIG was used as the magneto-optic crystal film, and L was used as the anisotropic crystal.
i Nb OS was used in each case, but the present invention is not limited thereto. For example, a crystal similar to YIG can be used as a diagonal crystal, a crystal in which Y (yttrium) is replaced with another rare earth element can be used as a magneto-optic crystal thin film, and LITaOs can be used as an anisotropic crystal.
You may use each.

本発明の光アイソレータの製造方法は上記実施例と全く
逆プロセスで行なってもよい、即ち、異方性結晶上に直
接、もしくは非晶質薄膜を介して磁気光学結晶薄膜を成
長し、この薄膜上に等方性結晶を成長させても、同様な
効果を有する光アイソレータを得ることができる。The method for manufacturing the optical isolator of the present invention may be carried out by a completely reverse process to that of the above embodiments. That is, a magneto-optic crystal thin film is grown directly on an anisotropic crystal or via an amorphous thin film, and this thin film is grown. An optical isolator with similar effects can be obtained by growing an isotropic crystal thereon.

〔発明の効果〕〔Effect of the invention〕

以上詳述した如く、本発明によれば磁気光学結晶薄膜と
異方性結晶との密着性が棗好で、優れた特性を有する等
方性結晶と磁気光学結晶薄膜と異方性結晶との三層構造
の光アイソレータを簡便に製造し得る方法を提供できる
。As detailed above, according to the present invention, the adhesion between the magneto-optic crystal thin film and the anisotropic crystal is excellent, and the isotropic crystal, the magneto-optic crystal thin film, and the anisotropic crystal have excellent properties. A method for easily manufacturing a three-layer optical isolator can be provided.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は従来のバルク形光アイソレータを示す構成図、
第２図は従来の導波形光アイソレータを示す構成図、第
３図は従来の別の導波形光アイソレータを示す構成図、
第４図線本発明の実施例１の方法によシ得られた導波形
光アイソレータを示す構成図、第５図は本発明の実施例
２により得られた導波形光アイソレータを示す構成図、
第６図は本発明の実施例３によシ得られ九導波形光アイ
ソレータを示す構成図である。 ２１・・・等方性結晶、２２・・・磁気光学結晶薄膜、
ｚｘｍｚｓ’、ｘｌ・・・異方性結晶、２１・・・溝、
２１・・・非晶質薄膜。 Ｉ！！１１！ｌｌ ｍ−「− 第２図 ２１３ 第３図 ５Figure 1 is a configuration diagram showing a conventional bulk type optical isolator.
FIG. 2 is a block diagram showing a conventional waveguide optical isolator, FIG. 3 is a block diagram showing another conventional waveguide optical isolator,
Fig. 4 is a block diagram showing a waveguide optical isolator obtained by the method of Example 1 of the present invention; Fig. 5 is a block diagram showing a waveguide optical isolator obtained by the method of Example 2 of the present invention;
FIG. 6 is a block diagram showing a nine-waveguide optical isolator obtained according to Example 3 of the present invention. 21... Isotropic crystal, 22... Magneto-optic crystal thin film,
zxmzs', xl...Anisotropic crystal, 21...Groove,
21...Amorphous thin film. I! ! 11! ll m-"- Fig. 2 213 Fig. 3 5

Claims (5)

【特許請求の範囲】[Claims] （１）　等方性結晶と異方性結晶とで磁気光学結晶薄膜
を挾んだサンドイッチ構造を有する光アイソレータの製
造において、等方性結晶上に順次磁気光学結晶薄膜と異
方性結晶を、或いは異方性結晶上に順次磁気光学結晶薄
膜と等方性結晶を、該磁気光学結晶薄膜と異方性結晶と
が良好に密着するように成長せしめることを特徴とする
光アイソレータの製造方法。(1) In manufacturing an optical isolator having a sandwich structure in which a magneto-optic crystal thin film is sandwiched between an isotropic crystal and an anisotropic crystal, a magneto-optic crystal thin film and an anisotropic crystal are sequentially placed on an isotropic crystal. Alternatively, a method for manufacturing an optical isolator, comprising growing a magneto-optic crystal thin film and an isotropic crystal sequentially on an anisotropic crystal such that the magneto-optic crystal thin film and the anisotropic crystal are in good contact with each other. （２）等方性結晶上の磁気光学結晶薄膜上に異方性結晶
を、或いは異方性結晶上に磁気光学結晶薄膜を成長させ
るに際し、基板となる磁気光学結晶薄膜或いは異方性結
晶上に１次元的或いは２次元的４溝を形成することを特
徴とする特許請求の範囲第１項記載の光アイソレータの
製造方法。(2) When growing an anisotropic crystal on a magneto-optic crystal thin film on an isotropic crystal, or a magneto-optic crystal thin film on an anisotropic crystal, the magneto-optic crystal thin film or anisotropic crystal becomes a substrate. The method for manufacturing an optical isolator according to claim 1, characterized in that four one-dimensional or two-dimensional grooves are formed in the optical isolator. （３）等方性結晶上の磁気光学結晶薄膜上に異方性結晶
を、或いは異方性結晶上に磁気光学結晶薄膜を成長させ
るに際し、基板となる磁気光学結晶薄膜或いは異方性結
晶上に２次元的にフラックスを塗着せしめることを特徴
とする特許請求の範囲第１ｒＡ記載の光アイソレータの
製造方法。(3) When growing an anisotropic crystal on a magneto-optic crystal thin film on an isotropic crystal, or a magneto-optic crystal thin film on an anisotropic crystal, the magneto-optic crystal thin film or anisotropic crystal as a substrate is grown. A method for manufacturing an optical isolator according to claim 1rA, characterized in that a flux is applied two-dimensionally to the optical isolator. （４）　　等方性結晶上の磁気光学結晶薄膜上に異方性
結晶を、或いは異方性結晶上に磁気光学結晶薄膜を成長
させるに際し、基板となる磁・気光学結晶薄膜或いは異
方性結晶上に非晶質薄膜を形成した徒、その上に異方性
結晶或いは磁気光学結晶薄膜を成長させることを特徴と
する特許請求の範囲第１項記載の光アイソレータの製造
方法。(4) When growing an anisotropic crystal on a magneto-optic crystal thin film on an isotropic crystal or a magneto-optic crystal thin film on an anisotropic crystal, the magneto-magneto-optic crystal thin film or anisotropic crystal that becomes the substrate 2. The method of manufacturing an optical isolator according to claim 1, wherein an amorphous thin film is formed on a crystal, and then an anisotropic crystal or a magneto-optic crystal thin film is grown thereon. （５）　　非晶質薄膜上に異方性結晶、或いは磁気光学
結晶薄膜を成長されるに際し、非晶質薄膜上に１次元的
又は２次元的に溝を形成することを特徴とする特許請求
の範囲第４項記載の光アイソレータの製造方法。(5) A patent claim characterized in that when an anisotropic crystal or magneto-optic crystal thin film is grown on an amorphous thin film, grooves are formed one-dimensionally or two-dimensionally on the amorphous thin film. A method for manufacturing an optical isolator according to item 4.