JPH0361172B2 - - Google Patents
Info
- Publication number
- JPH0361172B2 JPH0361172B2 JP59198611A JP19861184A JPH0361172B2 JP H0361172 B2 JPH0361172 B2 JP H0361172B2 JP 59198611 A JP59198611 A JP 59198611A JP 19861184 A JP19861184 A JP 19861184A JP H0361172 B2 JPH0361172 B2 JP H0361172B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- waveguides
- waveguide
- branch
- electric field
- 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 - Lifetime
Links
- 230000003287 optical effect Effects 0.000 claims description 19
- 238000009826 distribution Methods 0.000 description 55
- 230000005684 electric field Effects 0.000 description 47
- 230000000694 effects Effects 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000008033 biological extinction Effects 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/29—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the position or the direction of light beams, i.e. deflection
- G02F1/31—Digital deflection, i.e. optical switching
- G02F1/313—Digital deflection, i.e. optical switching in an optical waveguide structure
- G02F1/3137—Digital deflection, i.e. optical switching in an optical waveguide structure with intersecting or branching waveguides, e.g. X-switches and Y-junctions
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Integrated Circuits (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、導波路中を進む光の進行方向を電気
的に偏向させる光スイツチに関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical switch that electrically deflects the traveling direction of light traveling through a waveguide.
従来のこの種の光スイツチとして、方向性結合
器を備えたバランスドブリツジ型光導波路に電極
を設置することにより構成される導波路型光スイ
ツチがあり、この光スイツチは低電圧動作が可能
でかつ消光比が良いとう特長を有している。
A conventional optical switch of this type is a waveguide optical switch, which is constructed by installing electrodes on a balanced bridge optical waveguide equipped with a directional coupler, and this optical switch is capable of low voltage operation. It has the characteristics of being large and having a good extinction ratio.
〔発明が解決しようとする問題点〕
しかしながら、その反面、方向性結合器の製作
条件が厳しいという問題があり、また導波光の偏
光の種類によつてスイツチの寸法、形状を変えな
ければならず、そのため同一の光スイツチを用い
ることは不可能であるという問題もあつた。[Problems to be solved by the invention] However, on the other hand, there is a problem that the manufacturing conditions for the directional coupler are strict, and the dimensions and shape of the switch must be changed depending on the type of polarization of the guided light. Therefore, there was also the problem that it was impossible to use the same optical switch.
本発明はこのような問題点を解決するためにな
されたもので、製作条件を緩和できる導波路型光
スイツチを実現することを目的とする。 The present invention was made to solve these problems, and an object of the present invention is to realize a waveguide type optical switch that can ease manufacturing conditions.
上述した目的を達成するため、本発明は入力分
岐点および出力分岐点と、この入力分岐点および
出力分岐点間に接続された第１および第２の導波
路と、この第１および第２の導波路それぞれに近
接して配置された屈折率制御用の電極とを有する
バランスドブリツジ型の導波路型光スイツチにお
いて、前記入力分岐点と前記電極との間の領域お
よび前記出力分岐点と前記電極との間の領域にお
いて、前記第１および第２の導波路の幅が異なる
ことを特徴とする。
In order to achieve the above-mentioned object, the present invention includes an input branch point and an output branch point, first and second waveguides connected between the input branch point and the output branch point, and the first and second waveguides. In a balanced bridge waveguide optical switch having refractive index control electrodes disposed close to each waveguide, a region between the input branch point and the electrode and the output branch point The first waveguide and the second waveguide have different widths in a region between the electrodes.
以上の構成によると、非対称形分岐の光の偶モ
ードと奇モードの分離作用を利用し、電圧の印加
により光の位相を変化させてスイツチ動作させる
ことができる。
According to the above configuration, it is possible to perform a switch operation by changing the phase of the light by applying a voltage by utilizing the effect of separating the even mode and the odd mode of the light of the asymmetrical branch.
以下に本発明の実施例を図面を用いて説明す
る。
Embodiments of the present invention will be described below with reference to the drawings.
第１図は構成を示す平面図であり、図において
１ａ，１ｂは光の入力分岐導波路、２ａ，２ｂは
光の出力分岐導波路、３ａ，３ｂは入力分岐導波
路１ａ，１ｂ側に連なる分岐導波路、４ａ，４ｂ
は出力分岐導波路２ａ，２ｂ側に連なる分岐導波
路、５ａ，５ｂはそれぞれ分岐導波路３ａ，３ｂ
と分岐導波路４ａ，４ｂを結ぶ直線導波路、６
ａ，６ｂは各々の一部が直線導波路５ａ，５ｂ上
に重なるように設けられた屈折率制御用の電極で
ある。 FIG. 1 is a plan view showing the configuration. In the figure, 1a and 1b are optical input branching waveguides, 2a and 2b are optical output branching waveguides, and 3a and 3b are connected to the input branching waveguides 1a and 1b. Branch waveguide, 4a, 4b
are branch waveguides connected to the output branch waveguides 2a and 2b, and 5a and 5b are branch waveguides 3a and 3b, respectively.
and a straight waveguide connecting the branch waveguides 4a and 4b, 6
Reference characters a and 6b are refractive index control electrodes provided so that a portion of each of them overlaps the linear waveguides 5a and 5b.
さらに、上記した入力分岐導波路１ａ，１ｂお
よび出力分岐導波路２ａ，２ｂはそれぞれ同幅の
対称形分岐とし、かつ分岐導波路３ａ，４ｂを分
岐導波路３ｂ，４ａより幅を広くして非対称形分
岐とし、さらに直線導波路５ａ，５ｂは分岐導波
路３ａ，４ｂと３ｂ，４ａの中間の幅としたもの
である。つまり、入力側である分岐導波路３ａ，
３ｂおよび出力側である分岐導波路４ａ，４ｂを
それぞれ幅の異なる非対称形分岐構造に形成した
ものである。 Furthermore, the above-mentioned input branch waveguides 1a, 1b and output branch waveguides 2a, 2b are symmetrical branches with the same width, and the branch waveguides 3a, 4b are made wider than the branch waveguides 3b, 4a to make them asymmetrical. Furthermore, the straight waveguides 5a and 5b have a width intermediate between that of the branched waveguides 3a and 4b and those of the branched waveguides 3b and 4a. In other words, the branch waveguide 3a on the input side,
3b and branch waveguides 4a and 4b on the output side are each formed into an asymmetrical branch structure having different widths.
なお、７は入力分岐導波路１ａ，１ｂと分岐導
波路３ａ，３ｂとの接続部、８は出力分岐導波路
２ａ，２ｂと分岐導波路４ａ，４ｂとの接続部で
ある。 Note that 7 is a connection between the input branch waveguides 1a, 1b and the branch waveguides 3a, 3b, and 8 is a connection between the output branch waveguides 2a, 2b and the branch waveguides 4a, 4b.
非対称形分岐構造の作用は、例えば特開昭58−
202406号に示されるように、二本の導波路より成
る系では、偶モードと奇モードの二つの固有モー
ドが存在している。この系は等価屈折率法を用い
て二次元的な五層導波路として解析することが可
能である。この解析によれば、偶モードと奇モー
ドの界分布が、二本の導波路の等価屈折率差およ
び導波路間隔により大きく形状を変化することが
見出される。 The effect of the asymmetric branch structure is described, for example, in JP-A-58-
As shown in No. 202406, in a system consisting of two waveguides, there are two eigenmodes: an even mode and an odd mode. This system can be analyzed as a two-dimensional five-layer waveguide using the equivalent refractive index method. According to this analysis, it is found that the shape of the field distribution of even mode and odd mode changes greatly depending on the equivalent refractive index difference between the two waveguides and the waveguide spacing.
導波路間隔の狭い場合には、等価屈折率差が大
きい場合にも偶モードと奇モードの界分布は、二
本の導波路にほぼ等しいパワーを分配した形で一
方は等位相、他方は逆位相となつている。 When the waveguide spacing is narrow, even when the equivalent refractive index difference is large, the field distribution of even and odd modes is such that almost equal power is distributed to the two waveguides, with one having the same phase and the other having opposite phases. It is in phase.
導波路間隔が広くなると、等価屈折率差が大き
くなるに従つて偶モードの界分布は等価屈折率の
大きい導波路に大部分のパワーを配した形状とな
り、奇モードの界分布は等価屈折率の小さい導波
路に大部分のパワーを配した形状となる。 As the waveguide spacing becomes wider and the difference in equivalent refractive index increases, the field distribution of even modes will have a shape in which most of the power is distributed in the waveguide with a large equivalent refractive index, and the field distribution of odd modes will have a shape where the equivalent refractive index is larger. Most of the power is distributed in a small waveguide.
幅が異なる二本の導波路すなわち等価屈折率の
異なる二本の導波路の互いの間隔を一端では広く
他端では狭くしてハの字形に配置した場合、後述
する導波路間の角度（分岐角）、等価屈折率差等
の条件が適切である場合には、この構造を伝般す
る偶モード、奇モード間の変換を小さく抑えるこ
とが可能となる。これにより、この構造で以下に
示す機能を実現することができる。 When two waveguides with different widths, that is, two waveguides with different equivalent refractive indexes, are arranged in a V-shape with the interval between them being wider at one end and narrower at the other end, the angle between the waveguides (branching When conditions such as angle) and equivalent refractive index difference are appropriate, it is possible to suppress the conversion between the even mode and the odd mode propagating through this structure. Thereby, the following functions can be realized with this structure.
二本の導波路間の狭い部分において、二つの導
波路の光パワーが等しく等位相となる偶モードが
励起された場合、導波路間の広い部分では、等価
屈折率の高い導波路から光が出射される。二つの
導波路の光パワーが等しく逆位相となる奇モード
の場合には等価屈折率の低い導波路から光が出力
される。 If an even mode in which the optical powers of the two waveguides are equal and in phase is excited in the narrow part between the two waveguides, in the wide part between the waveguides, the light from the waveguide with a high equivalent refractive index is excited. It is emitted. In the case of an odd mode in which the optical powers of the two waveguides are equal and have opposite phases, light is output from the waveguide with a lower equivalent refractive index.
逆に、導波路間の広い部分から、一方の導波路
に光の入力される場合を考える。この場合、偶モ
ードと奇モードの励起される割合は、それぞれ偶
モードと入力光、奇モードと入力光の重畳積分と
なる。したがつて、等価屈折率の大きい導波路に
光を入力した場合には偶モードが励起され、等価
屈折率の小さい導波路に光を入力すれば奇モード
が励起される。これらのモードは導波路間の狭い
部分へ伝般していき、この部分で偶モードは二つ
の導波路に光パワーが等しく同位相の界分布、奇
モードでは等パワーで逆位相の界分布に変換され
る。 Conversely, consider a case where light is input into one waveguide from a wide area between the waveguides. In this case, the ratio of the even mode and the odd mode to be excited is the superposition integral of the even mode and the input light, and the odd mode and the input light, respectively. Therefore, when light is input into a waveguide with a large equivalent refractive index, the even mode is excited, and when light is input into a waveguide with a small equivalent refractive index, the odd mode is excited. These modes propagate to the narrow area between the waveguides, where the even mode has a field distribution with equal optical power and the same phase in the two waveguides, and the odd mode has a field distribution with equal power and opposite phase. converted.
そして、導波路間隔の狭い一端に、再び分岐角
の広い同一の幅の二本の導波路を接続すれば、導
波路間隔の狭い部分での二本の導波路の光パワー
の分配状態、位相状態を保存したまま、二本の導
波路へ光パワーを分けることが可能である。この
構造を非対称分岐という。 Then, if two waveguides of the same width with a wide branching angle are connected again to one end of the narrow waveguide interval, the distribution state of the optical power of the two waveguides at the narrow part of the waveguide interval, and the phase It is possible to divide optical power into two waveguides while preserving the state. This structure is called an asymmetric bifurcation.
そこで、上記構成による作用を第２図ＡからＤ
を用いて説明する。 Therefore, the effects of the above configuration are shown in Figure 2 A to D.
Explain using.
図において１５ａ〜１５ｄは入力光の電場強度
分布、１６ａ〜１６ｄは接続部７における偶モー
ドの電場強度分布、１７ａ〜１７ｄは同じく接続
部７における奇モードの電場強度分布である。ま
た、１８ａ〜１８ｄ、１９ａ〜１９ｄ、２０ａ〜
２０ｄおよび２１ａ〜２１ｄは直線導波路５ａ，
５ｂの両端部における電場強度分布、２２ａ〜２
２ｄは接続部８における偶モードの電場強度分
布、２３ａ〜２３ｄは接続部８における奇モード
の電場強度分布、２４ａ〜２４ｄは出力光の電場
強度分布である。 In the figure, 15a to 15d are electric field intensity distributions of input light, 16a to 16d are even mode electric field intensity distributions at the connection portion 7, and 17a to 17d are odd mode electric field intensity distributions at the connection portion 7. Also, 18a to 18d, 19a to 19d, 20a to
20d and 21a to 21d are straight waveguides 5a,
Electric field strength distribution at both ends of 5b, 22a-2
2d is an even mode electric field intensity distribution in the connection part 8, 23a to 23d is an odd mode electric field intensity distribution in the connection part 8, and 24a to 24d are electric field intensity distributions of output light.
(1) まず、光の非スイツチ動作状態を考える。(1) First, consider the non-switching operating state of light.
第２図Ａにおいて、入力分岐導波路１ａに入
力された電場強度分布１５ａを持つ光は、該入
力分岐導波路１ａを進んだ後、接続部７で電場
強度分布１６ａの偶モード光と電場強度分布１
７ａの奇モード光とに分かれ、非対称形分岐の
動作により偶モード光は幅の広い分岐導波路３
ａへ行き、奇モード光は幅の狭い分岐導波路３
ｂに行き、直線導波路５ａ，５ｂの始端でそれ
ぞれ電場強度分布１８ａ，１９ａの光となる。 In FIG. 2A, the light input to the input branch waveguide 1a and having the electric field intensity distribution 15a travels through the input branch waveguide 1a, and then at the connection part 7, the light with the electric field intensity distribution 16a and the electric field intensity Distribution 1
The even mode light is split into the odd mode light at 7a, and the even mode light is split into the wide branching waveguide 3 due to the asymmetric branching operation.
a, the odd mode light passes through the narrow branch waveguide 3.
b, and becomes light with electric field intensity distributions 18a and 19a at the starting ends of straight waveguides 5a and 5b, respectively.
この光は、そのまま直線導波路５ａ，５ｂを
直進し、その終端から電場強度分布２０ａ，２
１ａの光としてそれぞれ幅の狭い分岐導波路４
ａと幅の広い分岐導波路４ｂに入る。その後、
非対称形分岐の動作により接続部８で前記電場
強度分布２０ａの光は電場強度分布２３ａの奇
モード光に、また、電場強度分布２１ａの光は
電場強度分布２２ａの偶モード光になるので、
奇モード光と偶モード光の位相関係を電極６
ａ，６ｂに加える電圧により調整することによ
り出力分岐導波路２ａから電場強度分布２４ａ
の光が出力される。 This light travels straight through the straight waveguides 5a and 5b, and from the end thereof, electric field intensity distributions 20a and 2
Branch waveguides 4 each having a narrow width as the light of 1a
a and enters the wide branch waveguide 4b. after that,
Due to the operation of the asymmetric branch, the light with the electric field intensity distribution 20a becomes odd mode light with the electric field intensity distribution 23a at the connection part 8, and the light with the electric field intensity distribution 21a becomes even mode light with the electric field intensity distribution 22a.
The phase relationship between odd mode light and even mode light is determined by electrode 6.
The electric field intensity distribution 24a from the output branch waveguide 2a is adjusted by the voltage applied to a and 6b.
of light is output.
一方、第２図Ｃに示すように、入力分岐導波
路１ｂに電場強度分布１５ｃをもつ光が入力さ
れると、入力された光は入力分岐導波路１ｂに
進んだ後、接続部７において電場強度分布１６
ｃの偶モード光と、電場強度分布１７ｃの奇モ
ード光とに分かれる。このとき、この奇モード
光と偶モード光の位相関係は、上述した第２図
Ａの場合に比較してπだけずれている。 On the other hand, as shown in FIG. Intensity distribution 16
The light is divided into even mode light of c and odd mode light of electric field intensity distribution 17c. At this time, the phase relationship between the odd mode light and the even mode light is shifted by π compared to the case shown in FIG. 2A described above.
その後、非対称形分岐の動作により偶モード
光は幅の広い分岐導波路３ａへ、また奇モード
光は幅の狭い分岐導波路３ｂへそれぞれ移つて
行き、直線導波路５ａ，５ｂの始端においてそ
れぞれ電場強度分布１８ａ，１９ｃの光となる
が、ここでもやはり互いの位相差は第２図Ａの
場合に比較してπだけずれている。 Thereafter, by the operation of the asymmetric branch, the even mode light is transferred to the wide branch waveguide 3a, and the odd mode light is transferred to the narrow branch waveguide 3b, and the electric field is generated at the starting ends of the straight waveguides 5a and 5b. Although the light beams have intensity distributions 18a and 19c, their phase difference is also shifted by π compared to the case shown in FIG. 2A.
さらに、光はそのまま直線導波路５ａ，５ｂ
を直進し、その終端から電場強度分布２０ｃ，
２１ｃの光としてそれぞれ幅の狭い分岐導波路
４ａと幅の広い分岐導波路４ｂに入る。その
後、非対称形分岐の動作により接続部８で前記
電場強度分布２０ｃの光は電場強度分布２３ｃ
の奇モード光に、また、電場強度分布２１ｃの
光は電場強度分布２２ｃの偶モード光になる。
この奇モード光と偶モード光の位相関係も第２
図Ａの場合と同じ電圧が電極６ａ，６ｂに加わ
つているとき第２図Ａの場合に比べてπだけず
れているために、電場強度分布２４ｃの光が出
力分岐導波路２ｂから出力される。 Furthermore, the light is directly transmitted through the straight waveguides 5a and 5b.
Go straight ahead, and from the end, the electric field strength distribution 20c,
The light of 21c enters the narrow branch waveguide 4a and the wide branch waveguide 4b, respectively. Thereafter, due to the operation of the asymmetric branch, the light of the electric field intensity distribution 20c is transferred to the electric field intensity distribution 23c at the connection part 8.
The light with the electric field intensity distribution 21c becomes the even mode light with the electric field intensity distribution 22c.
The phase relationship between this odd mode light and even mode light is also
When the same voltage as in the case of Figure A is applied to the electrodes 6a and 6b, the light with the electric field intensity distribution 24c is output from the output branch waveguide 2b because it is shifted by π compared to the case of Figure 2A. .
(2) つぎに、光のスイツチ動作状態について考え
る。(2) Next, consider the operating state of the light switch.
第２図Ｂにおいて、入力分岐導波路１ａに入
力された電場強度分布１５ｂを持つ光は、該入
力分岐導波路１ａを進んだ後、接続部７で電場
強度分布１６ｂの偶モード光と電場強度分布１
７ｂの奇モード光とに分かれ、非対称形分岐の
動作により偶モード光は幅の広い分岐導波路３
ａへ行き、奇モード光は幅の狭い分岐導波路３
ｂに行き、直線導波路５ａ，５ｂの始端でそれ
ぞれ電場強度分布１８ｂ，１９ｂの光となる。 In FIG. 2B, the light input to the input branch waveguide 1a and having the electric field intensity distribution 15b travels through the input branch waveguide 1a, and then at the connection part 7, the light with the electric field intensity distribution 16b and the electric field intensity Distribution 1
The even mode light is split into the odd mode light at 7b, and the even mode light is split into the wide branching waveguide 3 due to the asymmetric branching operation.
a, the odd mode light passes through the narrow branch waveguide 3.
b, and becomes light with electric field intensity distributions 18b and 19b at the starting ends of straight waveguides 5a and 5b, respectively.
この光は、直線導波路５ａ，５ｂを進む間
に、電極６ａ，６ｂに加えられている電圧によ
り位相が変わり、終端において電場強度分布２
０ｂ，２１ｂのように第２図Ａの場合に比べて
互いにπだけ位相がずれる。 While this light travels through the linear waveguides 5a and 5b, its phase changes depending on the voltage applied to the electrodes 6a and 6b, and at the end, the electric field intensity distribution 2
0b and 21b, the phases are shifted by π compared to the case of FIG. 2A.
その後、電場強度分布２０ｂ，２１ｂの光は
幅の狭い分岐導波路４ａと幅の広い分岐導波路
４ｂに入り、非対称形分岐の動作により接続部
８で電場強度分布２０ｂの光は電場強度分布２
３ｂの奇モード光に、また、電場強度分布２１
ｂの光は電場強度分布２２ｂの偶モード光にな
る。この奇モード光と偶モード光の位相関係も
第２図Ａの場合に比べて互いにπだけ位相がず
れているために、第２図Ｃの場合と同様に出力
分岐導波路２ｂから電場強度分布２４ｂの光が
出力される。 Thereafter, the light with the electric field intensity distributions 20b and 21b enters the narrow branch waveguide 4a and the wide branch waveguide 4b, and due to the operation of the asymmetric branch, the light with the electric field intensity distribution 20b is transferred to the electric field intensity distribution 2 at the connection part 8.
3b, the electric field intensity distribution 21
The light b becomes even mode light of the electric field intensity distribution 22b. The phase relationship between the odd mode light and the even mode light is also shifted by π compared to the case of FIG. 2A, so the electric field intensity distribution from the output branch waveguide 2b is similar to the case of FIG. The light of 24b is output.
一方、第２図Ｄに示すように、入力分岐導波
路１ｂに電場強度分布１５ｄの光が入力される
と、入力された光は入力分岐導波路１ｂに進ん
だ後、接続部７において電場強度分布１６ｄの
偶モード光と、電場強度分布１７ｄの奇モード
光とに分かれる。このとき、この奇モード光と
偶モード光の位相関係は、上述した第２図Ｂの
場合に比較してπだけずれている。 On the other hand, as shown in FIG. 2D, when light with an electric field intensity distribution 15d is input to the input branch waveguide 1b, the input light advances to the input branch waveguide 1b and then reaches the connection part 7 with an electric field intensity of 15d. The light is divided into even mode light with a distribution of 16d and odd mode light with an electric field intensity distribution of 17d. At this time, the phase relationship between the odd mode light and the even mode light is shifted by π compared to the case shown in FIG. 2B described above.
その後、非対称形分岐の動作により偶モード
光は幅の広い分岐導波路３ａへ、また奇モード
光は幅の狭い分岐導波路３ｂへそれぞれ移つて
行き、直線導波路５ａ，５ｂの始端においてそ
れぞれ電場強度分布１８ｄ，１９ｄの光となる
が、ここでもやはり互いの位相差は第２図Ｂの
場合に比較してπだけずれている。 Thereafter, by the operation of the asymmetric branch, the even mode light is transferred to the wide branch waveguide 3a, and the odd mode light is transferred to the narrow branch waveguide 3b, and the electric field is generated at the starting ends of the straight waveguides 5a and 5b. The light beams have intensity distributions 18d and 19d, but their phase difference is also shifted by π compared to the case shown in FIG. 2B.
これらの光は直線導波路５ａ，５ｂを進む
が、その間に電極６ａ，６ｂに加えられている
電圧により位相が変化し、終端では電場強度分
布２０ｄ，２１ｄのように第２図Ａの場合と同
じ位相になる。 These lights travel through the straight waveguides 5a and 5b, but the phase changes due to the voltage applied to the electrodes 6a and 6b, and at the end, the electric field intensity distributions 20d and 21d differ from the case in FIG. 2A. be in the same phase.
その後、電場強度分布２０ｄ，２１ｄの光は
幅の狭い分岐導波路４ａと幅の広い分岐導波路
４ｂに入り、非対称形分岐の動作により接続部
８で電場強度分布２０ｄの光は電場強度分布２
３ｄの奇モード光に、また、電場強度分布２１
ｄの光は電場強度分布２２ｄの偶モード光にな
る。この奇モード光と偶モード光の位相関係も
第２図Ａの場合と同じ電圧が電極６ａ，６ｂに
加わつているとき第２図Ａの場合に比べてπだ
けずれているために、電場強度分布２４ｄの光
が出力分岐導波路２ａから出力される。つま
り、光スイツチ動作が行われる。 Thereafter, the light with the electric field intensity distributions 20d and 21d enters the narrow branch waveguide 4a and the wide branch waveguide 4b, and due to the operation of the asymmetric branch, the light with the electric field intensity distribution 20d is transferred to the electric field intensity distribution 2 at the connection part 8.
For the 3d odd mode light, the electric field intensity distribution 21
The light d becomes even mode light with an electric field intensity distribution 22d. The phase relationship between the odd mode light and the even mode light is also shifted by π compared to the case of FIG. 2A when the same voltage as in the case of FIG. 2A is applied to the electrodes 6a and 6b, so the electric field strength is Light having a distribution 24d is output from the output branching waveguide 2a. In other words, an optical switch operation is performed.
ここで、非対称形分岐導波路の特性について
述べると、その特性は、
Δβ／γθ＞const ……(1)
Δβ：入力分岐導波路３ａ，３ｂ間または出力
分岐導波路４ａ，４ｂの伝搬定数差
γ：導波路からの光のしみ出しを表すパラメー
タ
θ：入力分岐導波路３ａ，３ｂ間または出力分
岐導波路４ａ，４ｂが成す角度
const：定数；１以上
で表される。 Here, the characteristics of the asymmetric branch waveguide are as follows: Δβ/γθ>const (1) Δβ: Difference in propagation constant between input branch waveguides 3a and 3b or output branch waveguides 4a and 4b γ: Parameter representing the seepage of light from the waveguide θ: Angle formed between the input branch waveguides 3a and 3b or between the output branch waveguides 4a and 4b const: Constant; expressed as 1 or more.
上記(1)式は不等式であるため、TE、TMモ
ードを制御することを考えた場合、Δβ／γθの
小さいモードが動作する状態ならば、大きい方
のモードも動作する状態となり、TEモード、
TMモードの両方を同時に制御する事が可能で
ある。また、(1)式が不等式であることから、製
作条件も非常に緩いものとなる。 Since equation (1) above is an inequality, when considering controlling TE and TM modes, if the mode with smaller Δβ/γθ is in operation, the larger mode will also be in operation, and TE mode,
It is possible to control both TM modes at the same time. Furthermore, since equation (1) is an inequality, the manufacturing conditions are also very relaxed.
以上説明した如く本発明は、バランスドブリツ
ジ型光導波路の方向性結合器に該当する導波路を
入力側と出力側でそれぞれ非対称形分岐構造とな
るように形成しているため、従来に比べて製作条
性が緩和され、精密な設計を必要とせずに比較的
高い消光比が得られるという効果がある。
As explained above, in the present invention, the waveguide corresponding to the directional coupler of the balanced bridge type optical waveguide is formed so as to have an asymmetrical branch structure on the input side and the output side, so compared to the conventional one. This has the effect of easing the manufacturing process and making it possible to obtain a relatively high extinction ratio without requiring precise design.
第１図は実施例を示す平面図、第２図は作用を
示す説明図。
１ａ，１ｂ……入力分岐導波路、２ａ，２ｂ…
…出力分岐導波路、３ａ，３ｂ……分岐導波路、
４ａ，４ｂ……分岐導波路、５ａ，５ｂ……直線
導波路、６ａ，６ｂ……電極、７，８……接続
部。
FIG. 1 is a plan view showing the embodiment, and FIG. 2 is an explanatory diagram showing the operation. 1a, 1b...Input branch waveguide, 2a, 2b...
...output branch waveguide, 3a, 3b...branch waveguide,
4a, 4b... Branch waveguide, 5a, 5b... Straight waveguide, 6a, 6b... Electrode, 7, 8... Connection portion.
Claims (1)
岐点および出力分岐点間に接続された第１および
第２の導波路と、この第１および第２の導波路そ
れぞれに近接して配置された屈折率制御用の電極
とを有するバランスドブリツジ型の導波路型光ス
イツチにおいて、 前記入力分岐点と前記電極との間の領域および
前記出力分岐点と前記電極との間の領域におい
て、前記第１および第２の導波路の幅が異なるこ
とを特徴とする導波路型光スイツチ。[Claims] 1. An input branch point and an output branch point, first and second waveguides connected between the input branch point and the output branch point, and an input branch point and an output branch point, respectively, and first and second waveguides connected between the input branch point and the output branch point, and In a balanced bridge type waveguide optical switch having a refractive index control electrode disposed in close proximity to each other, a region between the input branch point and the electrode and a region between the output branch point and the electrode A waveguide type optical switch characterized in that the first and second waveguides have different widths in a region between them.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19861184A JPS6177033A (en) | 1984-09-25 | 1984-09-25 | Optical switch of waveguide type |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19861184A JPS6177033A (en) | 1984-09-25 | 1984-09-25 | Optical switch of waveguide type |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6177033A JPS6177033A (en) | 1986-04-19 |
| JPH0361172B2 true JPH0361172B2 (en) | 1991-09-19 |
Family
ID=16394066
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19861184A Granted JPS6177033A (en) | 1984-09-25 | 1984-09-25 | Optical switch of waveguide type |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6177033A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5465050A (en) * | 1977-10-11 | 1979-05-25 | Western Electric Co | Electromagnetic wave device |
-
1984
- 1984-09-25 JP JP19861184A patent/JPS6177033A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5465050A (en) * | 1977-10-11 | 1979-05-25 | Western Electric Co | Electromagnetic wave device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6177033A (en) | 1986-04-19 |
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