JPH04333829A - Waveguide type optical device - Google Patents
Waveguide type optical deviceInfo
- Publication number
- JPH04333829A JPH04333829A JP10583991A JP10583991A JPH04333829A JP H04333829 A JPH04333829 A JP H04333829A JP 10583991 A JP10583991 A JP 10583991A JP 10583991 A JP10583991 A JP 10583991A JP H04333829 A JPH04333829 A JP H04333829A
- Authority
- JP
- Japan
- Prior art keywords
- optical
- waveguide
- light
- substrate
- type optical
- 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 134
- 239000000758 substrate Substances 0.000 claims abstract description 29
- 230000008033 biological extinction Effects 0.000 abstract description 6
- 230000005855 radiation Effects 0.000 abstract description 3
- 230000008878 coupling Effects 0.000 description 12
- 238000010168 coupling process Methods 0.000 description 12
- 238000005859 coupling reaction Methods 0.000 description 12
- 239000013078 crystal Substances 0.000 description 11
- 238000011161 development Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 239000013307 optical fiber Substances 0.000 description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 238000004891 communication Methods 0.000 description 6
- 238000012827 research and development Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 238000012546 transfer Methods 0.000 description 4
- 229910003327 LiNbO3 Inorganic materials 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 3
- 235000012239 silicon dioxide Nutrition 0.000 description 3
- 239000000377 silicon dioxide Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011982 device technology Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000005469 synchrotron radiation Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
- G02F1/3132—Digital deflection, i.e. optical switching in an optical waveguide structure of directional coupler type
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Integrated Circuits (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、導波路型光デバイスに
関し、特に、光通信システムの構築に適する導波路型光
デバイスに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide type optical device, and more particularly to a waveguide type optical device suitable for constructing an optical communication system.
【０００２】0002
【従来の技術】光通信システムは商業化に成功して以来
、より大容量且つ多機能なシステムの完成を目指して、
今日なお活発な新技術開発活動が続けられている。[Prior Art] Ever since optical communication systems were successfully commercialized, efforts have been made to create systems with larger capacity and more functionality.
Today, active new technology development activities continue.
【０００３】現在、実用されている光通信システムは、
光信号を発生する手段に、半導体レーザまたは発光ダイ
オードの注入電流を直接制御する。所謂、直接変調方式
の光変調器を用い、また、光伝送路の切替えおよびネッ
トワークの交換機能を司どる手段に、プリズム、ミラー
または光ファイバ等を操作して光路を機械的に切替える
。所謂、機構形式の光スイッチを用いているのが通常で
ある。しかしながら、この種の光デバイスは、その動作
速度がいずれも低速で高速化することが極めて難しいと
いう本質的欠陥を有するので、通信システムの開設技術
としての意義は残るものの、この技術の延長線上に、目
標とする大容量、多機能の光通信システムの構築は無い
とするのが一般的評価である。すなわち、直接変調方式
は緩和振動であるため数ＧＨｚ 以上の高速変調器が得
がたいこと、また、波長安定性に難点があって、大容量
伝送が期待できるコーヒレント伝送方式への適用が難し
い等の欠点があり、他方、機構形式の光スイッチには、
低速動作の外に形状が大きくてマトリクス化に不適とい
う欠点が更に加わるので、今日実用されているデバイス
技術の単なる踏襲では、光交換などの新機能を備えた高
速光通信システムは、到底実現されないというのが一般
的見解である。[0003] Optical communication systems currently in use include:
The means for generating the optical signal directly controls the injection current of the semiconductor laser or light emitting diode. A so-called direct modulation type optical modulator is used, and the optical path is mechanically switched by operating a prism, a mirror, an optical fiber, or the like as a means for controlling the switching of the optical transmission line and the switching function of the network. A so-called mechanical type optical switch is usually used. However, this type of optical device has an essential flaw in that its operating speed is slow and it is extremely difficult to increase the speed, so although it remains significant as a technology for establishing communication systems, it cannot be used as an extension of this technology. The general assessment is that the targeted large-capacity, multifunctional optical communication system will not be constructed. In other words, the direct modulation method uses relaxation oscillation, so it is difficult to obtain a high-speed modulator of several GHz or more, and it also has disadvantages such as wavelength stability, which makes it difficult to apply it to coherent transmission methods that can expect large-capacity transmission. On the other hand, mechanical type optical switches include
In addition to low-speed operation, they have the added disadvantage of being large and unsuitable for matrix formation, so it is impossible to realize high-speed optical communication systems with new functions such as optical switching by simply following the device technology currently in use today. That is the general opinion.
【０００４】現在、これらの難点を解決するためのデバ
イス研究が活発に行われているが、今日最も有望と思わ
れている提案の一つに導波路型光デバイスがある。この
新型デバイスは、光のスイッチングまたは変調の機能を
全て基板上の光導波路に付与しようとするもので、研究
開発は２つの流れで進められている。すなわち、変調と
スイッチングとが本質的に同義である点に着目して、光
スイッチング素子の開発だけに的を絞る研究開発の一つ
の流れと、スイッチまたは変調器それぞれの単一機能素
子の開発を目指す他の一つの流れとがあり、例えば、基
板の電気光学効果を利用して光導波路の屈折率を変え光
路を切替える方向性結合器型、或いは、屈折率の変化に
よるミラー効果を利用して同じく光導波路の光路を切替
える全反射型などの光スイッチング素子、また、入力光
を２分しその一方に位相πの位相変調を行い、これら２
つを光導波路上で合成して“１”または“０”の変調信
号を出力するようにしたマッハツェンダ型（干渉光型）
光変調器など、これまでにも数多くの開発成果の報告が
なされている。これらの新型デバイスはいずれも開発途
上にあるので、互いの優劣を俄かに断ずることは出来な
いが、変調器またはスイッチのいずれにも適用できる点
から、光スイッチング素子の開発に高い評価が与えられ
ている。特に、ニオブ酸リチウム（ＬｉＮｂＯ３ ）結
晶の強誘電体材料を基板を用いた方向性結合型光スイッ
チング素子は、光導波路による光吸収損失が小さいこと
、大きな電気光学効果をもつため動作効率が高いこと、
また、スイッチ速度も極めて高速であるなどの特長を有
するので、今日最も有望なデバイス素子として注目され
ている。[0004] Currently, device research is being actively conducted to solve these difficulties, and one of the proposals that seems to be the most promising today is a waveguide type optical device. This new device aims to impart all optical switching or modulation functions to the optical waveguide on the substrate, and research and development is proceeding in two ways. In other words, focusing on the fact that modulation and switching are essentially synonymous, we will focus on one flow of research and development that focuses only on the development of optical switching devices, and the development of single-function devices for switches and modulators. There is another trend that we are aiming for, for example, a directional coupler type that uses the electro-optic effect of the substrate to change the refractive index of the optical waveguide and switch the optical path, or a directional coupler type that uses the mirror effect due to a change in the refractive index. Similarly, an optical switching element such as a total reflection type that switches the optical path of an optical waveguide, and an optical switching element that divides the input light into two and performs phase modulation of phase π on one of the two,
Mach-Zehnder type (interference light type) that combines two signals on an optical waveguide and outputs a modulated signal of "1" or "0"
Numerous development results have been reported so far, including optical modulators. Since all of these new devices are still in the development stage, it is not possible to immediately determine the superiority or inferiority of each other, but the development of optical switching elements has been highly evaluated because it can be applied to either modulators or switches. It is given. In particular, a directionally coupled optical switching element using a ferroelectric material of lithium niobate (LiNbO3) crystal as a substrate has low optical absorption loss due to the optical waveguide and a large electro-optic effect, resulting in high operating efficiency. ,
Furthermore, since it has features such as extremely high switching speed, it is attracting attention as the most promising device element today.
【０００５】従って、新型光デバイスの研究開発は、光
導波路型、なかんずく基板の電気光学効果を利用した方
向性結合器型光デバイスの実用化に集中した観があり、
例えば、ニオブ酸リチウム（ＬｉＮｂＯ３ ）基板上に
６４個の方向性結合器型光スイッチング素子を集積して
、８×８マトリクスの光スイッチを得たとする西本裕ら
の報告（電子情報通信学会誌論文、ＯＱＥ８８−１４７
）に見られるように、導波路型光スイッチング素子の高
密度集積化に関する研究開発が開発に行われるようにな
り、また、これと平行する形で単一素子構造の光変調器
の開発も強力に押し進められるようになった。Therefore, the research and development of new optical devices seems to have concentrated on the practical application of optical waveguide type optical devices, especially directional coupler type optical devices that utilize the electro-optic effect of the substrate.
For example, a report by Yutaka Nishimoto et al. (IEICE journal paper , OQE88-147
), research and development on high-density integration of waveguide-type optical switching devices has begun, and in parallel, development of optical modulators with a single-element structure is also gaining momentum. It became possible to push forward.
【０００６】図４は従来の導波路型光デバイスの一例を
示す斜視図で、方向性結合器型光スイッチング素子の構
造を示す。この種の光スイッチング素子は、通常、ニオ
ブ酸リチウム（ＬｉＮｂＯ３ ）結晶基板１と、結晶基
板１上に形成される一対の光導波路２ａ，２ｂと、これ
ら一対の光導波路２ａ，２ｂの一部近接領域の結晶基板
１上に形成される狭隘な一方向性の光パワー移動領域を
介して光導波路を相互に結合する方向性結合器３と、こ
れら一対の光導波路２ａ，２ｂの一部近接領域近傍の光
導波路上にバッファ層４を介してそれぞれ設けられる方
向性結合器３の結合制御電極５とから成り、結合制御電
極５の電圧制御による方向性結合器３の結合遮断または
再開の電気的制御によって、光路のスイッチング動作は
行われる。FIG. 4 is a perspective view showing an example of a conventional waveguide type optical device, and shows the structure of a directional coupler type optical switching element. This type of optical switching element usually includes a lithium niobate (LiNbO3) crystal substrate 1, a pair of optical waveguides 2a and 2b formed on the crystal substrate 1, and a portion of these pair of optical waveguides 2a and 2b located close to each other. A directional coupler 3 that couples optical waveguides to each other through a narrow unidirectional optical power transfer area formed on a crystal substrate 1 in a region, and a region partially adjacent to these pair of optical waveguides 2a and 2b. It consists of a coupling control electrode 5 of each directional coupler 3 provided on a nearby optical waveguide through a buffer layer 4, and an electrical connection cut-off or resumption of coupling of the directional coupler 3 by voltage control of the coupling control electrode 5. The switching operation of the optical path is performed by control.
【０００７】すなわち、結合制御電極５の両電極がいず
れも接地され電圧が印加されない状態では、一対の光導
波路２ａ，２ｂの間に形成された一方向性の光パワー移
動領域は何等の障害も受けないので、２つの光導波路は
方向性結合器３を介して完全な結合状態にある。従って
、ポートａから入力した光は、方向性結合器３を介して
他方の光導波路２ｂ側に移りポートＣから出射する。
また、結合制御電極５に電圧が印加され、一方の光導波
路２ａの電位が他方の光導波路２ｂより高く設置された
状態では、光導波路２ａ，２ｂの屈折率がいずれも変化
して、光導波路２ａから光パワー移動領域への光入射を
阻止する条件を作るので、方向性結合器３による２つの
光導波路間の結合は完全に遮断される。従って、この場
合におけるポートａからの入力光は、他方の光導波路２
ｂ側に移ることなく、そのまま直進してポートｂから出
射することとなる。すなわち、結合制御電極５の印加電
圧を制御することによって、光路の切替えが迅速に行わ
れる。That is, when both electrodes of the coupling control electrode 5 are grounded and no voltage is applied, the unidirectional optical power transfer region formed between the pair of optical waveguides 2a and 2b will not experience any hindrance. Therefore, the two optical waveguides are perfectly coupled via the directional coupler 3. Therefore, the light input from port a passes through the directional coupler 3 to the other optical waveguide 2b and exits from port C. Further, when a voltage is applied to the coupling control electrode 5 and the potential of one optical waveguide 2a is set higher than the other optical waveguide 2b, the refractive index of both optical waveguides 2a and 2b changes, and the optical waveguide Since conditions are created to prevent light from entering the optical power transfer region 2a, the coupling between the two optical waveguides by the directional coupler 3 is completely blocked. Therefore, in this case, the input light from port a is transmitted to the other optical waveguide 2.
Without moving to the b side, the light goes straight and is emitted from port b. That is, by controlling the voltage applied to the coupling control electrode 5, the optical path can be quickly switched.
【０００８】この種の光スイッチング素子は、結合制御
電極５に変調信号を印加すれば、変調信号の“１”また
は“０”に対応する“オン”または“オフ”の光信号が
ポートｃまたはｂからそれぞれ出射するので、光変調器
の構成に使用される。また、単一の光スイッチとしての
用途も活発であり、例えば、光ファイバの破断点測定用
計器に組込まれて使用される。この計測器は、光源から
被測定用光ファイバからの戻り光を受光素子で検知する
構成をもつものであるが、例えば、図４のポートａに被
測定用光ファイバを、また、ポートｂおよびｃにパルス
光源および受光素子をそれぞれ接続することによって、
極めて容易に実現される。この際、この光スイッチング
素子は、ポートａから入力する被測定用ファイバからの
戻り光をポートｃへと導く、光路スイッチとして機能す
ることとなる。In this type of optical switching element, when a modulation signal is applied to the coupling control electrode 5, an "on" or "off" optical signal corresponding to "1" or "0" of the modulation signal is transmitted to port c or Since each light is emitted from the light source b, it is used in the construction of an optical modulator. It is also actively used as a single optical switch, for example, by being incorporated into an instrument for measuring the break point of an optical fiber. This measuring instrument has a configuration in which a light receiving element detects the return light from the optical fiber to be measured from the light source. For example, the optical fiber to be measured is connected to port a in FIG. By connecting a pulsed light source and a light receiving element to c,
This is extremely easy to achieve. At this time, this optical switching element functions as an optical path switch that guides the return light from the fiber under test input from port a to port c.
【０００９】[0009]
【発明が解決しようとする課題】このように、光導波路
型光デバイスの研究開発が、光スイッチング素子を重点
に応用技術を含めて活発に行われているが、その中心課
題は、スイッチング電圧（電力）、クロストーク、消光
比、損失、スイッチング速度、温度および湿度などの環
境に対する安定性などの特性改善に向けられている。特
に、方向性結合器型光スイッチング素子は、光路の切替
えは一方向性の光パワー移動領域を介して行われ、切替
え径路に結晶基板が含まれるように構成されているので
、入力光の結晶基板への放射洩れが大きな問題として指
摘されている。すなわち、図４の光スイッチング素子の
場合では、ポートｃからポートｂへの光路切替えが終了
した後でも、光導波路２ａの屈曲部の縁端部近傍から結
晶基板１内へ光放射が少量ながら続き、ポートｃ側に流
れ込むという問題点が指摘されている。このように、結
晶基板１内に洩れた放射光が基板内を流れてポートｃ側
に到達すると、一般に消光比と呼ばれている特性を低下
せしめるので、光変調器の場合であれば、出力光信号の
“１”または“０”に対応する“オン”または“オフ”
の識別を困難とし、また、光ファイバの破断点測定用計
測器の場合であれば、受光素子が恰も光ファイバケーブ
ルに破断点が存在するかのように誤検知する危険が生じ
るなど、このましからざる問題点が多数発生する。[Problems to be Solved by the Invention] As described above, research and development of optical waveguide type optical devices is being actively carried out, including applied technology, with emphasis on optical switching elements, but the central issue is the switching voltage ( The aim is to improve properties such as power), crosstalk, extinction ratio, loss, switching speed, and stability against environments such as temperature and humidity. In particular, in a directional coupler type optical switching element, the optical path is switched via a unidirectional optical power transfer region, and the switching path includes a crystal substrate, so the input light is crystallized. Radiation leakage to the substrate has been pointed out as a major problem. That is, in the case of the optical switching element shown in FIG. 4, even after the optical path switching from port c to port b is completed, a small amount of light continues to be emitted into the crystal substrate 1 from near the edge of the bent portion of the optical waveguide 2a. , it has been pointed out that there is a problem that the water flows into the port c side. In this way, when the synchrotron radiation leaking into the crystal substrate 1 flows through the substrate and reaches the port c side, it reduces the characteristic generally called the extinction ratio, so in the case of an optical modulator, the output “On” or “off” corresponding to “1” or “0” of the optical signal
In addition, in the case of measuring instruments for measuring optical fiber break points, there is a risk that the light-receiving element may falsely detect a break point in the optical fiber cable. Many unforeseen problems arise.
【００１０】本発明の目的は、上記の情況に鑑み、入力
光の基板への放射洩れに基づく出力光の消光比低下の問
題点を改善した導波路型デバイスを提供することである
。SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a waveguide type device that improves the problem of reduced extinction ratio of output light due to radiation leakage of input light to a substrate.
【００１１】[0011]
【課題を解決するための手段】本発明によれば、基板上
に形成される２つの光導波路の光路のスイッチングを前
記光導波路の光学的性質を変化せしめることによって行
う導波路型光デバイスにおいて、前記光導波路近傍の基
板上に該光導波路よりも深い形状の遮光溝が光導波路に
沿って縦長に設けられることを特徴とする導波路型光デ
バイスが得られる。[Means for Solving the Problems] According to the present invention, in a waveguide-type optical device, the optical paths of two optical waveguides formed on a substrate are switched by changing the optical properties of the optical waveguides. A waveguide-type optical device is obtained, characterized in that a light shielding groove having a shape deeper than the optical waveguide is provided on the substrate near the optical waveguide in a longitudinal direction along the optical waveguide.
【００１２】0012
【実施例】以下図面を参照して本発明を詳細に説明する
。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the drawings.
【００１３】図１および図２はそれぞれ本発明の一実施
例を示す導波路型光デバイスの斜視図およびそのＡ−Ａ
′断面図である。本実施例は、従来例の図４と基本構造
を全く同一とする方向性結合型光スイッチング素子に実
施した場合と示すものである。従って、ポートｃ側の光
導波路近傍に新たに設けた遮光溝６以外の主要部には、
図４と同一の符号が付されている。本実施例によれば、
一対の光導波路２ａ，２ｂは、ニオブ酸リチウム結晶基
板１内にチタン（Ｔｉ）を熱拡散して形成され、また、
バッファ層４は二酸化ケイ素（ＳｉＯ２ ）膜で形成さ
れる。このバッファ層４の形成は、光導波路２ａ，２ｂ
内を伝搬する光のＴＭモード光のパワーが、結合制御電
極５の金属膜に吸収されるのを防止するのに、極めて有
効に作用する。FIGS. 1 and 2 are a perspective view of a waveguide type optical device showing one embodiment of the present invention, and its A-A
'It is a sectional view. This embodiment shows a case where the present invention is implemented in a directional coupling type optical switching element whose basic structure is completely the same as that of the conventional example shown in FIG. Therefore, in the main parts other than the newly provided light shielding groove 6 near the optical waveguide on the port c side,
The same reference numerals as in FIG. 4 are attached. According to this embodiment,
The pair of optical waveguides 2a and 2b are formed by thermally diffusing titanium (Ti) in the lithium niobate crystal substrate 1, and
Buffer layer 4 is formed of a silicon dioxide (SiO2) film. The formation of this buffer layer 4 is similar to that of the optical waveguides 2a and 2b.
This is extremely effective in preventing the power of the TM mode light propagating therein from being absorbed by the metal film of the coupling control electrode 5.
【００１４】ここで、ポートｃ側の光導波路近傍に新た
に設けられた遮光溝６は、結晶基板１内に洩れた放射光
が、ポートｃ側の光導波路２ｂの出力端部と結合するの
を阻止するよう作用する。実験した結果によれば、光導
波路２ｂの出力部の縁端から距離１０〜２０μｍ だけ
離間した位置に、光導波路の深さ（５μｍ ）より深い
１０〜２０μｍ の深さをもつ遮光溝６を設けた場合、
ポートｃにおけるノイズ量が激減することが観測され、
消光比が格段に改善されたことが確かめられた。Here, the light shielding groove 6 newly provided near the optical waveguide on the port c side prevents the emitted light leaking into the crystal substrate 1 from coupling with the output end of the optical waveguide 2b on the port c side. It acts to prevent According to the experimental results, a light-shielding groove 6 having a depth of 10 to 20 μm, which is deeper than the depth of the optical waveguide (5 μm), is provided at a distance of 10 to 20 μm from the edge of the output portion of the optical waveguide 2b. If
It was observed that the amount of noise at port c was drastically reduced,
It was confirmed that the extinction ratio was significantly improved.
【００１５】図３は本発明の他の実施例を示す導波路型
光デバイスの斜視図で、光変調器と光ファイバの破断点
測定用計測器とを同一基板上に搭載した構造を示したも
のである本実施例によれば、光導波路２ｂの出力部近傍
の両側には、一対の遮光溝６ａ，６ｂが光導波路を挾み
込むように配設され、また、入力側の光導波路２ａの入
力部の近傍には一つの遮光溝６ｃが配設される。一般に
、遮光溝は方向性結合器の近傍以外であれば、光導波路
に沿う何処の場所にも設けることが出来るが、出力端の
近傍に設けるのが最も効果的であり、これに入力端を加
えればなお一層の効果をあげることが出来る。FIG. 3 is a perspective view of a waveguide type optical device showing another embodiment of the present invention, showing a structure in which an optical modulator and a measuring device for measuring the break point of an optical fiber are mounted on the same substrate. According to this embodiment, a pair of light shielding grooves 6a and 6b are provided on both sides near the output portion of the optical waveguide 2b so as to sandwich the optical waveguide, and the optical waveguide 2a on the input side One light-shielding groove 6c is provided near the input section. Generally, a light-shielding groove can be provided anywhere along the optical waveguide except near the directional coupler, but it is most effective to provide it near the output end, and the input end is connected to this. If you add more, you can get even more effect.
【００１６】なお、本実施例における光導波路２ｃは信
号系には与らないダミー導波路で、信号系の光導波路２
ａ，２ｂ間の直接干渉を防止する役目を果たす。本実施
例のようにダミー導波路を用いると、３ａ，３ｂの２つ
の方向性結合器が必要となり、これに伴って結晶基板１
内への放射光の洩れ量も増加するが、この場合にあって
も遮光溝による効果は極めて顕著である。The optical waveguide 2c in this embodiment is a dummy waveguide that does not participate in the signal system, and the optical waveguide 2c in the signal system
It serves to prevent direct interference between a and 2b. When a dummy waveguide is used as in this embodiment, two directional couplers 3a and 3b are required, and along with this, the crystal substrate 1
The amount of inward leakage of light also increases, but even in this case, the effect of the light-shielding grooves is extremely significant.
【００１７】以上は方向性結合器型光デバイスに実施し
た場合のみを説明したが、全反射型光スイッチング素子
またはガリウム砒素（ＧａＡｓ）とインジウムリン（Ｉ
ｎＰ）との積層基板を用いた。その他の導波路型光デバ
イスに対して実施することも極めて容易である。[0017] The above description has been made only for the case where it is applied to a directional coupler type optical device.
A laminated substrate with nP) was used. It is also extremely easy to implement the present invention for other waveguide type optical devices.
【００１８】[0018]
【発明の効果】以上詳細に説明したように、本発明によ
れば、基板内に放射された入力光の洩れ光を、信号光が
出力するポートの光導波路の近傍、または、入力ポート
の光導波路の近傍に設けた遮光溝で捕捉し、出力ポート
への侵入を阻止することが出来るので、導波路型光デバ
イスの消光比特性の改善に格段の効果を挙げることが出
来る。As described above in detail, according to the present invention, the leakage light of the input light radiated into the substrate is removed from the optical waveguide near the port where the signal light is output or the optical waveguide of the input port. Since the light can be captured by the light-shielding groove provided near the waveguide and prevented from entering the output port, it can be significantly effective in improving the extinction ratio characteristics of the waveguide type optical device.
【図１】本発明の一実施例を示す導波路型光デバイスの
斜視図である。FIG. 1 is a perspective view of a waveguide type optical device showing one embodiment of the present invention.
【図２】図１のＡ−Ａ′断面図である。FIG. 2 is a sectional view taken along line AA' in FIG. 1;
【図３】本発明の他の実施例を示す導波路型光デバイス
の斜視図である。FIG. 3 is a perspective view of a waveguide type optical device showing another embodiment of the present invention.
【図４】従来の導波路型光デバイスの斜視図である。FIG. 4 is a perspective view of a conventional waveguide type optical device.
１ ＬｉＮｂＯ３ 結晶基板 ２ａ，２ｂ，２ｃ 光導波路 ３，３ａ，３ｂ 方向性結合器 ４ バッフィ層（ＳｉＯ２ ） ５，５ａ，５ｂ 結合制御電極 ６，６ａ，６ｂ，６ｃ 遮光溝 ａ，ｂ，ｃ ポート 1 LiNbO3 crystal substrate 2a, 2b, 2c Optical waveguide 3, 3a, 3b Directional coupler 4 Buffy layer (SiO2) 5, 5a, 5b Coupling control electrode 6, 6a, 6b, 6c Light shielding groove a, b, c port
Claims (3)
光路のスイッチングを前記光導波路の光学的性質を変化
せしめることによって行う導波路型光デバイスにおいて
、前記光導波路近傍の基板上に該光導波路よりも深い形
状の遮光溝が光導波路に沿って設けられることを特徴と
する導波路型光デバイス。1. A waveguide-type optical device in which the optical paths of two optical waveguides formed on a substrate are switched by changing the optical properties of the optical waveguides, wherein the optical waveguides are formed on a substrate near the optical waveguides. A waveguide-type optical device characterized in that a light-shielding groove deeper than the waveguide is provided along the optical waveguide.
傍の少なくとも片側の基板上に設けられることを特徴と
する請求項１記載の導波路型光デバイス。2. The waveguide type optical device according to claim 1, wherein the light shielding groove is provided on at least one side of the substrate near the output portion of the optical waveguide.
傍の少なくとも片側の基板上に設けられることを特徴と
する請求項１記載の導波路型光デバイス。3. The waveguide type optical device according to claim 1, wherein the light shielding groove is provided on at least one side of the substrate near the input portion of the optical waveguide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10583991A JPH04333829A (en) | 1991-05-10 | 1991-05-10 | Waveguide type optical device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10583991A JPH04333829A (en) | 1991-05-10 | 1991-05-10 | Waveguide type optical device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04333829A true JPH04333829A (en) | 1992-11-20 |
Family
ID=14418197
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10583991A Pending JPH04333829A (en) | 1991-05-10 | 1991-05-10 | Waveguide type optical device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04333829A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1111413A1 (en) * | 1999-12-23 | 2001-06-27 | Litton Systems, Inc. | Multifunction integrated optics chip having improved polarization extinction ratio |
| WO2004021075A1 (en) * | 2002-08-30 | 2004-03-11 | Sumitomo Osaka Cement Co., Ltd | Optical modulator |
-
1991
- 1991-05-10 JP JP10583991A patent/JPH04333829A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1111413A1 (en) * | 1999-12-23 | 2001-06-27 | Litton Systems, Inc. | Multifunction integrated optics chip having improved polarization extinction ratio |
| WO2004021075A1 (en) * | 2002-08-30 | 2004-03-11 | Sumitomo Osaka Cement Co., Ltd | Optical modulator |
| US7310453B2 (en) | 2002-08-30 | 2007-12-18 | Sumitomo Osaka Cement Co., Ltd. | Optical modulator |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7386198B2 (en) | Optical waveguide device | |
| JP2005221999A (en) | Optical modulator and optical modulator array | |
| JP2014194478A (en) | Optical device and transmitter | |
| JP4308712B2 (en) | Optical device | |
| KR100350414B1 (en) | Digital thermo-optic switch coupled with a variable optical attenuator | |
| JPH07318986A (en) | Waveguide type optical switch | |
| JPWO2005124438A1 (en) | Optical modulator with monitor photodetector | |
| JP6232751B2 (en) | Light modulator | |
| US7184631B2 (en) | Optical device | |
| JPH10260328A (en) | Optical modulating element | |
| JP2940141B2 (en) | Waveguide type optical control device | |
| JPH04328720A (en) | Waveguide type optical device | |
| JPH04333829A (en) | Waveguide type optical device | |
| US7373025B2 (en) | Waveguide-type optical device | |
| JP2936792B2 (en) | Waveguide type optical device | |
| JPS63313120A (en) | Optical polarization control element | |
| JPH05224044A (en) | Waveguide type optical device with monitor | |
| JP2011102891A (en) | Optical functional waveguide | |
| JP2903700B2 (en) | Waveguide type optical device | |
| JP2903702B2 (en) | Waveguide type optical device | |
| JP3139009B2 (en) | Light switch | |
| JPH05297420A (en) | Optical switch | |
| JPH1144867A (en) | Optical modulator module | |
| JP2009014826A (en) | Optical modulator with monitor photodetector | |
| JP3887552B2 (en) | Wavelength management apparatus and optical modulator management method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 19991117 |