JPH03119304A - Optical circuit - Google Patents
Optical circuitInfo
- Publication number
- JPH03119304A JPH03119304A JP25912289A JP25912289A JPH03119304A JP H03119304 A JPH03119304 A JP H03119304A JP 25912289 A JP25912289 A JP 25912289A JP 25912289 A JP25912289 A JP 25912289A JP H03119304 A JPH03119304 A JP H03119304A
- Authority
- JP
- Japan
- Prior art keywords
- optical
- loss
- optical waveguides
- dielectric film
- crystal substrate
- 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
- 230000003287 optical effect Effects 0.000 title claims abstract description 109
- 239000000758 substrate Substances 0.000 claims abstract description 21
- 239000013078 crystal Substances 0.000 claims abstract description 16
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 abstract description 13
- 229910052719 titanium Inorganic materials 0.000 abstract description 13
- 239000010936 titanium Substances 0.000 abstract description 13
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 5
- 238000006243 chemical reaction Methods 0.000 abstract description 3
- 230000008878 coupling Effects 0.000 abstract description 3
- 238000010168 coupling process Methods 0.000 abstract description 3
- 238000005859 coupling reaction Methods 0.000 abstract description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract description 2
- 239000000377 silicon dioxide Substances 0.000 abstract description 2
- 229910052681 coesite Inorganic materials 0.000 abstract 1
- 229910052906 cristobalite Inorganic materials 0.000 abstract 1
- 230000037431 insertion Effects 0.000 abstract 1
- 238000003780 insertion Methods 0.000 abstract 1
- 235000012239 silicon dioxide Nutrition 0.000 abstract 1
- 229910052682 stishovite Inorganic materials 0.000 abstract 1
- 229910052905 tridymite Inorganic materials 0.000 abstract 1
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 9
- 239000011159 matrix material Substances 0.000 description 8
- 238000004891 communication Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000031700 light absorption Effects 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000001459 lithography Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- DDFHBQSCUXNBSA-UHFFFAOYSA-N 5-(5-carboxythiophen-2-yl)thiophene-2-carboxylic acid Chemical compound S1C(C(=O)O)=CC=C1C1=CC=C(C(O)=O)S1 DDFHBQSCUXNBSA-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 229910052594 sapphire Inorganic materials 0.000 description 1
- 239000010980 sapphire Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000001039 wet etching Methods 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
Landscapes
- Optical Integrated Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は結晶基板上に設けた光導波路を用いた光回路に
関し、さらに詳しくは光導波路同士が交差して構成され
る光回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical circuit using optical waveguides provided on a crystal substrate, and more particularly to an optical circuit constructed by intersecting optical waveguides.
光通信システムの実用化が進むにつれ、さらに大容量や
多機能を持つ高度のシステムが求められており、光伝送
路の切り替え、交換や数多くの光信号の分配、合流など
の新たな機能の付加が必要とされている。光伝送路の切
り替えやネットワークの交換機能を得る手段としては光
スィッチが使用される。現在実用されている光スィッチ
は、プリズム、ミラー、ファイバーなどを機械的に移動
させるものであり、低速であること、信顆性が不十分、
形状が大きくマトリクス化に不適当の欠点がある。これ
を解決する手段として開発が進められているものは光導
波路を用いた導波形の光スィッチであり、高速、多素子
の集積化が可能、高信頼等の特長がある。特にニオブ酸
リチウム(LiNb0s)結晶等の強誘電体材料を用い
たものは、光吸収が小さく低損失であること、大きな電
気光学効果を有しているため高効率である等の特長があ
り、従来からも方向性結合器型光スイッチ、全反射型光
スイッチまたはマツハツエンダ型光スイッチ等の種々の
方式の光スィッチが報告されている。As the practical use of optical communication systems progresses, advanced systems with larger capacity and multiple functions are required, and new functions such as switching and exchanging optical transmission lines and distributing and merging numerous optical signals are being added. is needed. Optical switches are used as means for switching optical transmission lines and providing network switching functions. Optical switches currently in use mechanically move prisms, mirrors, fibers, etc., and are slow and have insufficient reliability.
The disadvantage is that the shape is large, making it unsuitable for matrix formation. A waveguide type optical switch using an optical waveguide is being developed as a means to solve this problem, and has features such as high speed, integration of multiple elements, and high reliability. In particular, those using ferroelectric materials such as lithium niobate (LiNb0s) crystals have features such as low light absorption and low loss, and high efficiency because they have a large electro-optic effect. Various types of optical switches have been reported in the past, such as a directional coupler type optical switch, a total internal reflection type optical switch, and a Matsuhatsu Enda type optical switch.
特に導波形光スイッチ間を基板上に光導波路からなる光
回路で接続し、多数個集積したマトリクス光スィッチは
光信号の切り替え、交換の目的にはキーデバイスである
ため数多くの検討及び報告がされている。このような導
波形のマトリクス光スィッチを実際の光通信システムに
適用する場合、低損失であることが重要であり、このた
めにはマトリクス光スィッチを構成する光回路が低損失
であることが不可欠である。In particular, many studies and reports have been made on matrix optical switches, which connect waveguide optical switches with optical circuits made of optical waveguides on a substrate, and are a key device for the purpose of switching and exchanging optical signals. ing. When applying such a waveguide matrix optical switch to an actual optical communication system, it is important to have low loss, and for this purpose, it is essential that the optical circuit that makes up the matrix optical switch has low loss. It is.
一方、光信号を分配したり、合流する場合には現在は光
ファイバを用いているが、今後分配及び合流させる光信
号数の増化に伴い光スィッチが大型化し、信号数増大に
対しては不適当である。これを解決する手段として開発
が進められているものは、やはり光導波路を用いた導波
形の光回路である。光ファイバと同じ材料である石英系
光導波路、ガラス板及びニオブ酸リチウム(LiNb0
.)結晶等の誘電体基板に形成した光導波路を用いた光
回路は、光吸収が小さく低損失であるため数多くの報告
がされているが、やはり、実際の光通信システムに適用
する際には光回路が低損失であることが実用上不可欠で
ある。On the other hand, optical fibers are currently used to distribute and combine optical signals, but as the number of optical signals to be distributed and combined increases in the future, optical switches will become larger. It's inappropriate. A waveguide type optical circuit using an optical waveguide is currently being developed as a means to solve this problem. A silica-based optical waveguide, a glass plate, and lithium niobate (LiNb0), which are the same materials as optical fibers, are used.
.. ) Many reports have been made of optical circuits using optical waveguides formed on dielectric substrates such as crystals, as they have low optical absorption and low loss, but it is still difficult to apply them to actual optical communication systems. It is practically essential that optical circuits have low loss.
〔発明が解決しようとする課題〕
しかし、従来の光回路では光回路の損失に関して十分な
特性は得られていない。第2図(a)。[Problems to be Solved by the Invention] However, conventional optical circuits do not have sufficient characteristics regarding optical circuit loss. Figure 2(a).
(b)に従来の光導波路が交差して構成される光回路の
一例として百本 裕らの文献、電子通信情報学会 技術
報告 ○QE、88−147による8×8マトリクス光
スイツチの光回路の平面図を示す、第2図(a)におい
て、Z軸に垂直に切り出しなニオブ酸リチウム結晶基板
11の上にチタン膜を形成した後熱拡散して、屈折率を
基板よりも大きくして形成した埋め込み形のシングルモ
ード光導波路12及び13が形成されている。光導波路
12及び13は基板の中央部で互いに数μm程度まで近
接し、方向性結合器14を形成している。第2図(a)
°では前記方向性結合器14が64素子同−基板上に集
積されて8×8マトリクス光スイツチが構成している。(b) is an example of an optical circuit constructed by crossing conventional optical waveguides, as shown in the literature by Yutaka Hyakumoto et al., Technical Report of the Institute of Electronics, Communication and Information Engineers, ○QE, 88-147, an optical circuit of an 8×8 matrix optical switch. In FIG. 2(a), which shows a plan view, a titanium film is formed on a lithium niobate crystal substrate 11 cut perpendicularly to the Z axis, and then thermally diffused to make the refractive index larger than that of the substrate. Embedded single mode optical waveguides 12 and 13 are formed. The optical waveguides 12 and 13 are close to each other within several μm at the center of the substrate, forming a directional coupler 14. Figure 2(a)
In this case, the directional coupler 14 has 64 elements integrated on the same substrate to form an 8.times.8 matrix optical switch.
第2図(b)は各方向性結合器14間を接続する光導波
路12及び13が交差する領域を拡大した平面図である
。FIG. 2(b) is an enlarged plan view of the area where the optical waveguides 12 and 13 that connect the directional couplers 14 intersect.
前述した文献によれば、8×8マトリクス光スイツチの
接続バスによる損失の違いは2本の光導波路12及び1
3の交差部での損失(今後、交差損失と呼ぶ)に起因す
ること、また、低損失化を得るためには交差損失の低減
が必要であることが明かとされている。前述した接続バ
スの違いによる損失の差は、各接続バスにおける2本の
光導波路12及び13が交差する交差部の数の違いに起
因している。すなわち前述した文献によれば交差損失は
、TM偏光に対して一つの交差部で0.35dB程度あ
り、この時各接続パスが有する交差部は0点から15点
と異なるためである。従って、有する交差点が0点と1
5点の接続バスの間には交差損失だけで約5dBの損失
の差が発生するという課題が生じる。こうした接続バス
の違いによる損失の差を低減し実用的な光スィッチを得
るためには、交差損失を低損失化することが必要となる
。According to the above-mentioned literature, the difference in loss due to the connection bus of an 8×8 matrix optical switch is due to the two optical waveguides 12 and 1.
It has been clarified that this is caused by loss at the intersection of No. 3 (hereinafter referred to as "crossing loss"), and that it is necessary to reduce the crossing loss in order to reduce the loss. The difference in loss due to the difference in the connection buses described above is due to the difference in the number of intersections where the two optical waveguides 12 and 13 intersect in each connection bus. That is, according to the above-mentioned literature, the crossing loss is about 0.35 dB at one crossing point for TM polarized light, and this is because each connection path has different crossing points from 0 to 15 points. Therefore, the intersections it has are 0 and 1.
A problem arises in that a difference in loss of approximately 5 dB occurs between the five connection buses due to cross loss alone. In order to reduce the difference in loss due to the difference in connection buses and obtain a practical optical switch, it is necessary to reduce the crossing loss.
シングルモードで伝搬してきた導波光は、交差する2本
の導波路が近接する領域から交差部にかけてマルチモー
ドとなり、交差部を通過後は交差する2本の導波路が離
れた領域で再びシングルモードとなる。このため交差部
20でのモード変換、モード結合及び交差して近接する
もう一方の導波路への導波光の移行などにより、交差損
失が発生する。The guided light that has propagated in single mode becomes multimode from the area where the two intersecting waveguides are close to the intersection, and after passing through the intersection, it becomes single mode again in the area where the two intersecting waveguides are separated. becomes. Therefore, cross loss occurs due to mode conversion at the cross section 20, mode coupling, and transfer of the guided light to the other adjacent waveguide that intersects.
ところで、第2図(b)において斜線で示したひし形の
交差部20の屈折率を導波路12及び13より高くする
と、この部分での導波路の閉じ込めが強くなり、交差損
失を低減できることは、既に多数の文献で紹介されてい
る(例えば、T、Kurokawaらの文献APPLI
ED 0PTICS、Vol、16.Na4゜Apri
l 1977、p、1033)。一方、チタン膜の熱拡
散によって形成される光導波路の屈折率を部分的に高く
するためには、特公昭61−25642号公報に記載さ
れているように、複数回のチタン成膜工程とリソグラフ
ィー法によりチタンパクンの膜厚を部分的に増加する方
法がある。By the way, if the refractive index of the diamond-shaped crossing part 20 shown by diagonal lines in FIG. It has already been introduced in many documents (for example, the document APPLI by T. Kurokawa et al.
ED 0PTICS, Vol. 16. Na4゜Apri
l 1977, p. 1033). On the other hand, in order to partially increase the refractive index of an optical waveguide formed by thermal diffusion of a titanium film, multiple titanium film formation steps and lithography are required, as described in Japanese Patent Publication No. 61-25642. There is a method of partially increasing the film thickness of titanium protein.
この技術を利用して第3図に示すようにひし形の交差部
20のみにチタン膜を2層形成することで、交差部20
の屈折率が導波路12及び13より高い光回路を形成す
ることができる。ここで第3図(a)は、ひし形の交差
部20のみにチタン膜を2層形成したパタンの平面図で
あり、第3図(b)は第3図(a)のAA’断面図であ
る。しかしながら、前記の技術では交差部を有する光回
路を形成するまでに、コストが高く成膜に要する時間の
長いチタン成膜工程が複数回必要であるという課題が生
じる。Using this technology, as shown in FIG. 3, by forming two layers of titanium film only on the diamond-shaped intersection 20,
It is possible to form an optical circuit in which the refractive index of the waveguides is higher than that of the waveguides 12 and 13. Here, FIG. 3(a) is a plan view of a pattern in which two layers of titanium film are formed only at the diamond-shaped intersections 20, and FIG. 3(b) is a cross-sectional view taken along line AA' in FIG. 3(a). be. However, the above-mentioned technique has a problem in that it requires multiple titanium film formation steps that are expensive and take a long time to form before forming an optical circuit having intersections.
なお、第2図(a)に示した8×8マトリクス光スイツ
チの64素子の各方向性結合器型光スイッチにおいて、
方向性結合器14を構成する光導波路上には制御電極1
5による光吸収を防ぐためのバッファ層を介して制御電
極15が形成されている。第2図(b)において、光導
波路12に入射した入射光17は方向性結合器14の部
分を伝搬するにしたがって近接した光導波路13へ徐々
に光エネルギーが移り、方向性結合器14を通過後は光
導波I¥813にほぼ100%エネルギーが移って出射
光18となる。一方、制御電極15に電圧を印加した場
合、電気光学効果により制御電極15下の光導波路の屈
折率が変化し、光導波路12と13を伝搬する導波モー
ドの間に位相速度の不整合が生じ、両者の間の結合状態
は変化する。この動作を用いて導波光の伝搬路の切り替
えを行っている。In addition, in each directional coupler type optical switch of 64 elements of the 8×8 matrix optical switch shown in FIG. 2(a),
A control electrode 1 is provided on the optical waveguide constituting the directional coupler 14.
A control electrode 15 is formed with a buffer layer interposed therebetween to prevent light absorption by the rays 5. In FIG. 2(b), as the incident light 17 that has entered the optical waveguide 12 propagates through the directional coupler 14, the optical energy gradually transfers to the adjacent optical waveguide 13 and passes through the directional coupler 14. After that, almost 100% of the energy is transferred to the optical waveguide I ¥813 and becomes the emitted light 18. On the other hand, when a voltage is applied to the control electrode 15, the refractive index of the optical waveguide under the control electrode 15 changes due to the electro-optic effect, causing phase velocity mismatch between the waveguide modes propagating in the optical waveguides 12 and 13. occurs, and the bonding state between the two changes. This operation is used to switch the propagation path of the guided light.
本発明の目的は、上述の従来の光回路の課題を解決し、
低損失かつ容易に形成できる光回路を提供することにあ
る。The purpose of the present invention is to solve the above-mentioned problems of the conventional optical circuit,
An object of the present invention is to provide an optical circuit that has low loss and can be easily formed.
本発明の光回路は、結晶基板上に形成された複数の光導
波路が互いに交差して構成される光回路において、前記
光導波路同士が交差している交差部に前記結晶基板より
低屈折率の誘電体膜を有して形成される。In the optical circuit of the present invention, in an optical circuit constituted by a plurality of optical waveguides formed on a crystal substrate, which intersect with each other, the intersection portions where the optical waveguides intersect with each other have a refractive index lower than that of the crystal substrate. It is formed with a dielectric film.
本発明の光回路は、光導波路同士が交差している交差部
に結晶基板より低屈折率の誘電体膜を有するため、誘電
体膜を装荷した交差部の等側屈折率はチタンを拡散して
得られた光導波路より高くなる。このため従来の構造に
比べ、交差部において光導波路は導波光の閉じ込めが強
くなり、交差部ではマルチモード成分が発生しないか、
または、発生してもその割合は小さく、前述した交差損
失の要因であるモード変換による損失、モード結合によ
る損失及び近接する他方の光導波路への導波光の移行に
よる損失がそれぞれ減少するため、交差損失は大幅に低
減される。Since the optical circuit of the present invention has a dielectric film having a lower refractive index than the crystal substrate at the intersection where the optical waveguides intersect, the isolateral refractive index of the intersection loaded with the dielectric film is such that titanium is diffused. It is higher than the optical waveguide obtained by Therefore, compared to the conventional structure, the optical waveguide has stronger confinement of guided light at the intersection, and multimode components are not generated at the intersection.
Or, even if it does occur, its proportion is small, and the loss due to mode conversion, loss due to mode coupling, and loss due to transition of guided light to the other adjacent optical waveguide, which are the causes of crossover loss mentioned above, are reduced. Losses are significantly reduced.
ここで、本発明の光回路を形成するためのチタン成膜工
程は一回であり、また誘電体膜は、制御電極による光吸
収を防ぐために形成する5i02膜やAl2O3膜等の
バッファ層を利用することによって容易に形成すること
ができる。Here, the titanium film forming process for forming the optical circuit of the present invention is performed only once, and the dielectric film uses a buffer layer such as a 5i02 film or an Al2O3 film formed to prevent light absorption by the control electrode. It can be easily formed by
以上のように、本発明の光回路では交差損失を低減でき
、従来の光回路に比べて交差部を有する光回路が低損失
かつ容易に得られる。As described above, in the optical circuit of the present invention, crossing loss can be reduced, and an optical circuit having crossing parts can be easily obtained with lower loss than conventional optical circuits.
以下、本発明の実施例について、図面を参照して詳細に
説明する。Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
第1図(a)、(b)は本発明による光回路の一実施例
である光導波路の交差部の平面図、断面図を示す。FIGS. 1(a) and 1(b) show a plan view and a sectional view of an intersection of optical waveguides, which is an embodiment of the optical circuit according to the present invention.
本実施例における誘電体膜16は、光導波路12.13
が形成されたニオブ酸リチウム結晶基板11の全面に形
成した膜厚約2800オングストロームの5i02スパ
ツタ膜について、制御電極15の周辺部及び交差部20
以外の部分をエツチング除去することで形成した。すな
わち、SiO□スパッタ膜を形成した後に、制御電極1
5(第2図参照)の周辺部及びひし形の交差部20をマ
スクし、マスクした以外の部分をフッ化アンモニウムと
フッ酸の混合溶液によるウェットエツチング法によって
除去した。The dielectric film 16 in this embodiment is the optical waveguide 12.13.
Regarding the 5i02 sputtered film with a thickness of approximately 2800 angstroms formed on the entire surface of the lithium niobate crystal substrate 11 on which
It was formed by etching away the other parts. That is, after forming the SiO□ sputtered film, the control electrode 1
5 (see FIG. 2) and the diamond-shaped intersection 20 were masked, and the remaining portions were removed by wet etching using a mixed solution of ammonium fluoride and hydrofluoric acid.
従来の光回路では交差損失が7M偏光に対して一つの交
差部で約0j5dBであったのに対し、本実施例による
光回路では交差損失は約0.1dBとなり、従来例に比
べ著しく小さくなった。また本実施例の光回路は、リソ
グラフィー法による5i02スパツタ膜のエツチング除
去工程を追加するだけで容易に形成できた。この時、光
導波路12及び13の幅Wは9μm、誘電体膜16の厚
さHは2800オングストローム、光導波路の交差角θ
は約7度(ただし7度以上)であり、光導波路は、ニオ
ブ酸リチウム結晶基板11に厚さ630オングストロー
ムのチタンを1050℃で8時間熱拡散することにより
形成した。In the conventional optical circuit, the crossing loss was about 0j5 dB at one crossing point for 7M polarized light, whereas in the optical circuit according to this embodiment, the crossing loss was about 0.1 dB, which is significantly smaller than the conventional example. Ta. Further, the optical circuit of this example could be easily formed by simply adding an etching removal process of the 5i02 sputtered film by lithography. At this time, the width W of the optical waveguides 12 and 13 is 9 μm, the thickness H of the dielectric film 16 is 2800 angstroms, and the crossing angle θ of the optical waveguides is 9 μm.
is about 7 degrees (but not less than 7 degrees), and the optical waveguide was formed by thermally diffusing titanium with a thickness of 630 angstroms on the lithium niobate crystal substrate 11 at 1050° C. for 8 hours.
なお、本発明による光回路を形成する光導波路は、ニオ
ブ酸リチウム結晶基板にチタンを拡散したものに限定さ
れず、ガラス基板やニオブ酸リチウムを用いたプロトン
交換光導波路、サファイア、St基板上に形成する石英
系光導波路など全ての光回路に適用できるのは明かであ
る。Note that the optical waveguide forming the optical circuit according to the present invention is not limited to one in which titanium is diffused on a lithium niobate crystal substrate, but can also be formed on a glass substrate, a proton exchange optical waveguide using lithium niobate, a sapphire, or an St substrate. It is obvious that the present invention can be applied to all optical circuits including quartz-based optical waveguides.
以上述べたように、本発明による光回路では、従来の光
回路に比べ、交差部を有する光回路が低損失かつ容易に
得られる。As described above, in the optical circuit according to the present invention, an optical circuit having a crossing portion can be easily obtained with low loss compared to a conventional optical circuit.
第1図(a)、(b)は本発明による光回路の一例を示
す平面図と断面図を示す、第2図(a)。
(b)は従来の光回路の一例を示す平面図であり、第3
図(a)、(b)は、交差部にチタン膜を2層形成した
パタンの平面図及び断面図である。
11・・・ニオブ酸リチウム結晶基板、12.13・・
・光導波路、14・・・方向性結合器、15・・・制御
電極、16・・・誘電体膜、17・・・入射光、18・
・・出射光、20・・・交差部。FIGS. 1(a) and 1(b) are a plan view and a sectional view showing an example of an optical circuit according to the present invention, and FIG. 2(a) is a sectional view of the optical circuit according to the present invention. (b) is a plan view showing an example of a conventional optical circuit;
Figures (a) and (b) are a plan view and a cross-sectional view of a pattern in which two layers of titanium films are formed at intersections. 11... Lithium niobate crystal substrate, 12.13...
- Optical waveguide, 14... Directional coupler, 15... Control electrode, 16... Dielectric film, 17... Incident light, 18.
... Outgoing light, 20... Intersection.
Claims (1)
て構成される光回路において、前記光導波路同士が交差
している交差部に前記結晶基板より低屈折率の誘電体膜
を有することを特徴とする光回路。An optical circuit configured by a plurality of optical waveguides formed on a crystal substrate intersecting each other, characterized in that a dielectric film having a lower refractive index than the crystal substrate is provided at the intersection where the optical waveguides intersect with each other. optical circuit.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP25912289A JPH03119304A (en) | 1989-10-03 | 1989-10-03 | Optical circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP25912289A JPH03119304A (en) | 1989-10-03 | 1989-10-03 | Optical circuit |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH03119304A true JPH03119304A (en) | 1991-05-21 |
Family
ID=17329622
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP25912289A Pending JPH03119304A (en) | 1989-10-03 | 1989-10-03 | Optical circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH03119304A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2326977A4 (en) * | 2008-09-04 | 2016-01-06 | Hewlett Packard Development Co | Dielectric waveguide intersection with reduced losses |
-
1989
- 1989-10-03 JP JP25912289A patent/JPH03119304A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2326977A4 (en) * | 2008-09-04 | 2016-01-06 | Hewlett Packard Development Co | Dielectric waveguide intersection with reduced losses |
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