JP2002169130A - Optical attenuator - Google Patents
Optical attenuatorInfo
- Publication number
- JP2002169130A JP2002169130A JP2000370390A JP2000370390A JP2002169130A JP 2002169130 A JP2002169130 A JP 2002169130A JP 2000370390 A JP2000370390 A JP 2000370390A JP 2000370390 A JP2000370390 A JP 2000370390A JP 2002169130 A JP2002169130 A JP 2002169130A
- Authority
- JP
- Japan
- Prior art keywords
- optical
- attenuator
- optical attenuator
- light
- waveguides
- 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 169
- 239000002184 metal Substances 0.000 claims abstract description 20
- 239000010409 thin film Substances 0.000 claims abstract description 20
- 239000000758 substrate Substances 0.000 claims abstract description 10
- 230000002238 attenuated effect Effects 0.000 claims description 8
- 238000010438 heat treatment Methods 0.000 claims description 5
- 238000002955 isolation Methods 0.000 abstract description 6
- 239000013307 optical fiber Substances 0.000 description 15
- 230000001902 propagating effect Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000010453 quartz Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 206010037660 Pyrexia Diseases 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Landscapes
- Optical Integrated Circuits (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
Abstract
(57)【要約】
【課題】 小型で各チャネル間のアイソレーションが確
実な光減衰器を提供する。
【解決手段】 各光減衰部５ａ〜５ｄの位置を基板２３
上の光信号の伝播方向と平行な方向にずらしたことによ
り、光信号の伝播方向に垂直な方向の長さを大きくする
ことなく、各光減衰部５ａ〜５ｄ間の間隔を大きくする
ことができるので、光減衰部５ａ〜５ｄの金属薄膜ヒー
タが加熱しても隣接する光減衰部５ａ〜５ｄへの熱の影
響のない光減衰器２０が得られる。また、各光減衰部５
ａ〜５ｄをジグザグ状にずらして配置することにより、
光減衰部５ａ〜５ｄの金属薄膜ヒータ４ａ〜４ｈのいず
れかが加熱しても隣接する光減衰部５ａ〜５ｄへの熱の
影響がなくなるだけでなく、光減衰器３０の光信号の伝
播方向の長さを短くすることができる。
PROBLEM TO BE SOLVED: To provide an optical attenuator which is small in size and ensures isolation between channels. SOLUTION: The positions of respective light attenuating parts 5a to 5d are set on a substrate 23.
By shifting the optical signal in the direction parallel to the propagation direction of the optical signal, it is possible to increase the distance between the light attenuating portions 5a to 5d without increasing the length in the direction perpendicular to the propagation direction of the optical signal. As a result, even if the metal thin film heaters of the light attenuating sections 5a to 5d are heated, an optical attenuator 20 having no influence on the adjacent light attenuating sections 5a to 5d can be obtained. In addition, each light attenuation unit 5
By disposing a to 5d in a zigzag manner,
Even if any of the metal thin film heaters 4a to 4h of the light attenuators 5a to 5d heats, not only the influence of heat on the adjacent light attenuators 5a to 5d is eliminated but also the propagation direction of the optical signal of the optical attenuator 30. Can be shortened.
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、光減衰器に関す
る。[0001] The present invention relates to an optical attenuator.
【０００２】[0002]
【従来の技術】光ファイバ通信に用いられるデバイスと
して光減衰器がある。2. Description of the Related Art There is an optical attenuator as a device used for optical fiber communication.
【０００３】図４（ａ）は従来の光減衰器の平面図であ
り、図４（ｂ）は図４（ａ）のＤ−Ｄ線断面図である。
図５は図４（ａ）に示した光減衰器のＤ−Ｄ線方向の温
度分布を示す図であり、横軸が位置を示し、縦軸が温度
を示している。FIG. 4 (a) is a plan view of a conventional optical attenuator, and FIG. 4 (b) is a sectional view taken along the line DD of FIG. 4 (a).
FIG. 5 is a diagram showing the temperature distribution in the DD line direction of the optical attenuator shown in FIG. 4A, wherein the horizontal axis indicates the position and the vertical axis indicates the temperature.
【０００４】この光減衰器１は、一対の光導波路２ａ、
２ｂが一対のＹ分岐光導波路３ａ、３ｂの分岐側間に並
列接続され、その並列接続された光導波路２ａ、２ｂに
金属薄膜ヒータ４ａ、４ｂがそれぞれ取付けられた光減
衰部５ａと、光減衰部５ａの一方（図では左側）のＹ分
岐光導波路３ａの合流側に接続され光信号が入力される
入力用光導波路６ａと、光減衰部の他方（図では右側）
のＹ分岐光導波路３ｂの合流側に接続され光強度が減衰
された光信号が出力される出力用光導波路７ａとが同一
の石英基板８上に４組並列に配置されたものである。The optical attenuator 1 includes a pair of optical waveguides 2a,
A light attenuating section 5a in which metal thin film heaters 4a and 4b are attached to the parallel-connected optical waveguides 2a and 2b, respectively; An input optical waveguide 6a, which is connected to the converging side of the Y-branch optical waveguide 3a on one side (left side in the figure) of the section 5a and receives an optical signal, and the other of the optical attenuation section (right side in the figure)
The four output optical waveguides 7a connected to the converging side of the Y-branch optical waveguide 3b and outputting an optical signal whose optical intensity is attenuated are arranged in parallel on the same quartz substrate 8.
【０００５】各光導波路２ａ〜２ｈ、３ａ〜３ｈは石英
基板８上に形成された導波路コア２ａ〜２ｈ、３ａ〜３
ｈと、導波路コア２ａ〜２ｈ、３ａ〜３ｈを覆うと共に
導波路コア２ａ〜２ｈ、３ａ〜３ｈより屈折率の低いク
ラッド９とで構成されている。Each of the optical waveguides 2a to 2h, 3a to 3h is a waveguide core 2a to 2h, 3a to 3h formed on a quartz substrate 8.
h and a cladding 9 that covers the waveguide cores 2a to 2h and 3a to 3h and has a lower refractive index than the waveguide cores 2a to 2h and 3a to 3h.
【０００６】光減衰器１の入力側は４本の入力用光ファ
イバ１０ａ〜１０ｄを有する入力用光ファイバアレイ１
１に接続され、光減衰器１の出力側は４本の出力用光フ
ァイバ１２ａ〜１２ｄを有する出力用光ファイバアレイ
１３に接続されている。The input side of the optical attenuator 1 is an input optical fiber array 1 having four input optical fibers 10a to 10d.
The output side of the optical attenuator 1 is connected to an output optical fiber array 13 having four output optical fibers 12a to 12d.
【０００７】この光減衰器１の入力用光導波路６ａ〜６
ｄのうち、例えば入力用光導波路６ａを伝播する光信号
は、Ｙ分岐構造によって光導波路２ａ、２ｂに一旦分岐
された後、再度Ｙ分岐構造によって合流される。このよ
うな光導波路２ａ、２ｂに分岐された光信号は、クラッ
ド９の表面に取付けられた金属薄膜ヒータ４ａ、４ｂの
いずれか一方、例えば光導波路４ａを加熱することによ
り、光導波路２ａのみが加熱されて屈折率が変化する
（熱光学効果）。この時加熱された方の光導波路２ａを
伝播する光信号に位相遅れが生じ、その結果、入力用光
ファイバ１０ａ及び入力用光導波路６ａを伝播してきた
光信号は、出力用光導波路７ａに再度結合する際に減衰
して出力用光ファイバ１２ａを伝播する。The input optical waveguides 6a to 6 of the optical attenuator 1
Among the signals d, for example, an optical signal propagating through the input optical waveguide 6a is once branched into the optical waveguides 2a and 2b by the Y-branch structure, and then joined again by the Y-branch structure. The optical signal branched into such optical waveguides 2a and 2b is heated by heating one of the metal thin film heaters 4a and 4b attached to the surface of the clad 9, for example, the optical waveguide 4a, so that only the optical waveguide 2a is heated. Heating changes the refractive index (thermo-optic effect). At this time, a phase delay occurs in the optical signal propagating through the heated optical waveguide 2a. As a result, the optical signal propagating through the input optical fiber 10a and the input optical waveguide 6a is again transmitted to the output optical waveguide 7a. The light is attenuated when coupled and propagates through the output optical fiber 12a.
【０００８】この光減衰器１は、光導波路２ａと光導波
路２ｂとの間に温度差を付加することによって（図５参
照。）、出力光信号に減衰が発生するものであり、その
温度差（換言すると金属薄膜ヒータ４ａの電力）を調節
することによって減衰量を調節することができるように
なっている。In this optical attenuator 1, an output optical signal is attenuated by adding a temperature difference between the optical waveguide 2a and the optical waveguide 2b (see FIG. 5). By adjusting (in other words, the power of the metal thin film heater 4a), the amount of attenuation can be adjusted.
【０００９】この光減衰器１は、光減衰部５ａ〜５ｄを
光信号の伝播方向に対して垂直な方向（中央）に複数個
配置することにより複数チャネル（図では４チャネル）
を実現している。This optical attenuator 1 has a plurality of channels (four channels in the figure) by arranging a plurality of optical attenuators 5a to 5d in a direction (center) perpendicular to the propagation direction of an optical signal.
Has been realized.
【００１０】[0010]
【発明が解決しようとする課題】ところで、図４
（ａ）、（ｂ）に示した光減衰器１の金属薄膜ヒータ４
ａで発生した熱は、光減衰器１全体に伝導して図５に示
すような温度分布をもたらせる結果となる。このため、
金属薄膜ヒータ４ａが通電されている光減衰部５ａに隣
接する光導波路２ｃ、６ｂ、７ｂや光減衰部５ｂにも若
干の温度差が生じ、その結果、出力用光導波路７ａを伝
播する光信号だけでなく、出力用光導波路７ｂを伝播す
る光信号の光強度にも減衰を起こさせてしまい、チャネ
ル間のアイソレーションに影響を及ぼしてしまう（光減
衰部５ａに隣接する光減衰部５ｂの光導波路２ｃに０．
５℃の温度差が発生すると０．５ｄＢの減衰が発生す
る。）。By the way, FIG.
(A), the metal thin film heater 4 of the optical attenuator 1 shown in (b)
The heat generated in (a) is transmitted to the entire optical attenuator 1, resulting in a temperature distribution as shown in FIG. For this reason,
A slight temperature difference also occurs in the optical waveguides 2c, 6b, 7b and the optical attenuator 5b adjacent to the optical attenuator 5a to which the metal thin film heater 4a is energized, and as a result, the optical signal propagating through the output optical waveguide 7a. Not only that, the optical intensity of the optical signal propagating through the output optical waveguide 7b is also attenuated, thereby affecting the isolation between channels (the optical attenuator 5b adjacent to the optical attenuator 5a). 0. 0 in the optical waveguide 2c.
When a temperature difference of 5 ° C. occurs, attenuation of 0.5 dB occurs. ).
【００１１】そこで、隣接する光減衰部５ａ〜５ｄの影
響を十分小さくするためには、隣接光減衰部５ａ〜５ｄ
間の間隔を大きくとる必要があるが、結果として基板８
が光信号の伝播方向に垂直な方向の長さが大きくなって
しまうという問題があった。In order to sufficiently reduce the influence of the adjacent light attenuators 5a to 5d, the adjacent light attenuators 5a to 5d
It is necessary to increase the distance between the substrates, but as a result,
However, there is a problem that the length in the direction perpendicular to the propagation direction of the optical signal becomes large.
【００１２】そこで、本発明の目的は、上記課題を解決
し、小型で各チャネル間のアイソレーションが確実な光
減衰器を提供することにある。SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an optical attenuator which is small and ensures isolation between channels.
【００１３】[0013]
【課題を解決するための手段】上記目的を達成するため
に本発明の光減衰器は、一対の光導波路が一対のＹ分岐
光導波路の分岐側間に並列接続され、その並列接続され
た光導波路の少なくとも一方に金属薄膜ヒータが取付け
られた光減衰部と、光減衰部の一方のＹ分岐光導波路の
合流側に接続され光信号が入力される入力用光導波路
と、光減衰部の他方のＹ分岐光導波路の合流側に接続さ
れ金属薄膜ヒータの通電加熱で生じる屈折率変化に伴う
位相差により光強度が減衰された光信号が出力される出
力用光導波路とが同一基板上に複数組並列に配置された
光減衰器において、各光減衰部が光信号の伝播方向と平
行な方向に位置をずらして配置されているものである。In order to achieve the above object, an optical attenuator according to the present invention comprises a pair of optical waveguides connected in parallel between the branch sides of a pair of Y-branch optical waveguides. An optical attenuator having a metal thin film heater attached to at least one of the waveguides, an input optical waveguide connected to the converging side of one of the Y-branch optical waveguides of the optical attenuator and receiving an optical signal, and the other of the optical attenuator And a plurality of output optical waveguides connected to the converging side of the Y-branch optical waveguide and outputting an optical signal whose optical intensity is attenuated by a phase difference caused by a change in refractive index caused by energization heating of the metal thin film heater on the same substrate. In the optical attenuators arranged in pairs, each optical attenuator is arranged so as to be shifted in a direction parallel to the propagation direction of the optical signal.
【００１４】上記構成に加え本発明の光減衰器は、各光
減衰部の光導波路間の間隔Ａと、各入出力用光導波路の
間隔Ｂと、各光減衰部間の入出力用光導波路に沿った方
向の間隔ＣとがＡ＜Ｂ＜Ｃとなるように配置されている
ものである。In addition to the above configuration, the optical attenuator according to the present invention includes an interval A between the optical waveguides of each optical attenuator, an interval B between the input / output optical waveguides, and an input / output optical waveguide between the optical attenuators. Are arranged so that the interval C in the direction along the line satisfies A <B <C.
【００１５】上記構成に加え本発明の光減衰器は、各光
減衰部がジグザグ状にずらして配置されているものであ
る。In addition to the above configuration, the optical attenuator of the present invention is such that the respective optical attenuators are arranged in a zigzag manner.
【００１６】本発明によれば、光減衰部の位置を基板上
の光信号の伝播方向と平行な方向にずらしたことによ
り、光減衰器の光信号の伝播方向に垂直な方向の長さを
大きくすることなく、光減衰部間の間隔を大きくするこ
とができるので、光減衰部の金属薄膜ヒータが加熱して
も隣接する光減衰部への熱の影響がなくなる。また、各
光減衰部をジグザグ状にずらして配置することにより、
光減衰部の金属薄膜ヒータが加熱しても隣接する光減衰
部への熱の影響がなくなるだけでなく、光減衰器の光信
号の伝播方向の長さを短くすることができる。According to the present invention, the length of the optical attenuator in the direction perpendicular to the propagation direction of the optical signal is reduced by shifting the position of the optical attenuator in the direction parallel to the propagation direction of the optical signal on the substrate. Since the distance between the light attenuating portions can be increased without increasing the size, even if the metal thin film heater of the light attenuating portion is heated, there is no influence of heat on the adjacent light attenuating portion. Also, by disposing each light attenuating part in a zigzag shape,
Even if the metal thin film heater of the light attenuator heats, not only the influence of heat on the adjacent light attenuator is eliminated, but also the length of the optical attenuator in the propagation direction of the optical signal can be shortened.
【００１７】[0017]
【発明の実施の形態】以下、本発明の実施の形態を添付
図面に基づいて詳述する。Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
【００１８】図１は本発明の光減衰器の一実施の形態を
示す平面図であり、図２は図１に示した光減衰器の説明
図である。尚、図４（ａ）、（ｂ）に示した部材と同様
の部材には共通の符号を用いた。FIG. 1 is a plan view showing an embodiment of the optical attenuator of the present invention, and FIG. 2 is an explanatory diagram of the optical attenuator shown in FIG. Note that common members are used for members similar to those shown in FIGS. 4A and 4B.
【００１９】図１に示す光減衰器２０は、一対の光導波
路２ａ、２ｂが一対のＹ分岐光導波路３ａ、３ｂの分岐
側間に並列接続され、その並列接続された光導波路２
ａ、２ｂの両方（少なくとも一方であってもよい。）に
金属薄膜ヒータ４ａ、４ｂが取付けられた光減衰部５ａ
と、光減衰部５ａの一方（図では左側）のＹ分岐光導波
路３ａの合流側に接続され光信号が入力される入力用光
導波路２１ａと、光減衰部５ａの他方（図では右側）の
Ｙ分岐光導波路３ｂの合流側に接続され金属薄膜ヒータ
４ａ、４ｂのいずれか一方の通電加熱で生じる屈折率変
化に伴う位相差により光強度が減衰された光信号が出力
される出力用光導波路２２ａとが同一の石英基板２３上
に複数組（図では４組であるが限定されない。）並列に
配置され、同様の光減衰部５ｂ〜５ｄが光信号の伝播方
向と平行な方向に位置をずらして配置されているもので
ある。In an optical attenuator 20 shown in FIG. 1, a pair of optical waveguides 2a and 2b are connected in parallel between the branch sides of a pair of Y-branch optical waveguides 3a and 3b, and the parallel-connected optical waveguide 2
Light attenuator 5a having metal thin film heaters 4a, 4b attached to both (or at least one of them) a and 2b
An input optical waveguide 21a connected to the converging side of one Y-branch optical waveguide 3a (left side in the figure) of the optical attenuator 5a and receiving an optical signal; and the other (right side in the figure) of the optical attenuator 5a An output optical waveguide that is connected to the converging side of the Y-branch optical waveguide 3b and outputs an optical signal whose light intensity has been attenuated by a phase difference caused by a change in refractive index caused by energization heating of one of the metal thin film heaters 4a and 4b. 22a are arranged in parallel on the same quartz substrate 23 (in the figure, four sets are not limited), and similar light attenuators 5b to 5d are positioned in a direction parallel to the propagation direction of the optical signal. They are staggered.
【００２０】光減衰部５ａの光導波路２ａ、２ｂ間の間
隔Ａと、入力（出力）用光導波路６ａ、６ｂ（７ａ、７
ｂ）の間隔Ｂと、光減衰部５ａ、５ｂ間の光信号の伝搬
方向に沿った方向の間隔ＣとはＡ＜Ｂ＜Ｃとなるように
配置されている。他の光減衰部５ｂ〜５ｄについても同
様である。The distance A between the optical waveguides 2a and 2b of the optical attenuator 5a and the input (output) optical waveguides 6a and 6b (7a and 7)
The interval B in b) and the interval C in the direction along the propagation direction of the optical signal between the optical attenuators 5a and 5b are arranged so that A <B <C. The same applies to the other light attenuation parts 5b to 5d.
【００２１】光減衰器２０の入力側は４本の入力用光フ
ァイバ１０ａ〜１０ｄを有する入力用光ファイバアレイ
１１に接続され、光減衰器１の出力側は４本の出力用光
ファイバ１２ａ〜１２ｄを有する出力用光ファイバアレ
イ１３に接続されている。The input side of the optical attenuator 20 is connected to an input optical fiber array 11 having four input optical fibers 10a to 10d, and the output side of the optical attenuator 1 is connected to four output optical fibers 12a to 12d. It is connected to an output optical fiber array 13 having 12d.
【００２２】次に図１に示した光減衰器２０の作用につ
いて図２を参照して説明する。Next, the operation of the optical attenuator 20 shown in FIG. 1 will be described with reference to FIG.
【００２３】例えば光減衰部５ａに光減衰を与えるた
め、金属薄膜ヒータ４ｂに電力を印加すると、通電加熱
で生じる屈折率変化に伴う位相差により、光ファイバ１
０ａに入力された光信号は光強度が減衰された後、出力
用光導波路２２ａを経て出力用光ファイバ１２ａから出
力されるが、このときの温度分布は、図２に示すように
なる。等温線Ｌ１の温度をＴ１とし、等温線Ｌ２の温度
をＴ２とし、等温線Ｌ３の温度をＴ３とし、等温線Ｌ４
の温度をＴ４とし（Ｔ１＞Ｔ２＞Ｔ３＞Ｔ４）、温度Ｔ
３は光減衰部５ａ〜５ｄに影響を与えない温度とする。For example, when electric power is applied to the metal thin-film heater 4b in order to apply light attenuation to the light attenuation section 5a, the optical fiber 1
The optical signal input to 0a is output from the output optical fiber 12a via the output optical waveguide 22a after the light intensity is attenuated, and the temperature distribution at this time is as shown in FIG. The temperature of the isotherm L1 is T1, the temperature of the isotherm L2 is T2, the temperature of the isotherm L3 is T3, and the isotherm L4
T4 (T1>T2>T3> T4), and the temperature T
Reference numeral 3 denotes a temperature that does not affect the light attenuation parts 5a to 5d.
【００２４】金属薄膜ヒータ４ｂで発生した熱の等温線
Ｌ１（温度Ｔ１）は、破線で示す光減衰部（図４（ａ）
に示す従来例に相当）５ｂｂの一方（図では上側）の光
導波路２ｃｃと接触し、等温線Ｌ２（温度Ｔ２）も光減
衰部５ｂｂの他方（図では下側）の光導波路２ｄｄと接
触している。このため、光減衰部５ａに隣接する光減衰
部５ｂｂは、光減衰部５ａの金属薄膜ヒータ４ｂで発生
した熱の影響を受けることが分かる。The heat isotherm L1 (temperature T1) of the heat generated by the metal thin film heater 4b is represented by a light attenuating portion indicated by a broken line (FIG. 4A).
) And the isothermal line L2 (temperature T2) also contacts the optical waveguide 2dd on the other side (lower side in the figure) of the light attenuator 5bb. ing. Therefore, it can be seen that the light attenuator 5bb adjacent to the light attenuator 5a is affected by the heat generated in the metal thin film heater 4b of the light attenuator 5a.
【００２５】これに対して図１に示した光減衰器２０の
光減衰部５ａに隣接する光減衰部５ｂは等温線Ｌ１、Ｌ
２には接触しておらず、わずかに等温線Ｌ３が光減衰部
５ｂの光導波路２ｃに接触している。On the other hand, the light attenuator 5b adjacent to the light attenuator 5a of the optical attenuator 20 shown in FIG.
2, the isotherm L3 is slightly in contact with the optical waveguide 2c of the light attenuation section 5b.
【００２６】従って光減衰部５ａの金属薄膜ヒータ４ｂ
の熱が隣接する光減衰部５ｂに漏れたとしても、光導波
路２ｃ、２ｄ間の温度差はごく小さく抑えることがで
き、光減衰部５ｂの光減衰量に影響を及ぼさない。Therefore, the metal thin film heater 4b of the light attenuating section 5a
Even if the heat leaks to the adjacent light attenuating portion 5b, the temperature difference between the optical waveguides 2c and 2d can be kept very small, and does not affect the light attenuation of the light attenuating portion 5b.
【００２７】すなわち、本光減衰器２０は光信号の伝播
方向と垂直な方向の長さを大きくすることなく、光減衰
部５ａ〜５ｄ間の間隔をＣ大きくすることができるの
で、光減衰部５ａの金属薄膜ヒータ４ｂを通電加熱して
も隣接する光減衰部５ｂへの熱の影響がない。That is, the optical attenuator 20 can increase the distance between the optical attenuators 5a to 5d by C without increasing the length in the direction perpendicular to the propagation direction of the optical signal. Even if the metal thin film heater 4b of 5a is energized and heated, there is no influence of heat on the adjacent light attenuation section 5b.
【００２８】従って、小型で各チャネル間のアイソレー
ションが確実な光減衰器の提供を実現することができ
る。Therefore, it is possible to provide an optical attenuator which is small and has reliable isolation between channels.
【００２９】図３は本発明の光減衰器の他の実施の形態
を示す平面図である。FIG. 3 is a plan view showing another embodiment of the optical attenuator of the present invention.
【００３０】図１に示した実施の形態との相違点は、各
光減衰部５ａ〜５ｄをジグザグ状にずらして配置した点
である。尚、３１ａ〜３１ｄは入力用光導波路を示し、
３２ａ〜３２ｄは出力用光導波路を示し、３３は基板を
示している。The difference from the embodiment shown in FIG. 1 is that the light attenuating portions 5a to 5d are arranged in a zigzag manner. 31a to 31d indicate input optical waveguides,
32a to 32d indicate output optical waveguides, and 33 indicates a substrate.
【００３１】このような光減衰器３０においても図１に
示した光減衰器２０と同様の効果が得られるだけでな
く、各光減衰部５ａ〜５ｄをジグザグ状にずらして配置
することにより、光減衰器３０の光信号の伝播方向の長
さを短くすることができ、図１に示した光減衰器３０よ
りも小型化することができる。In such an optical attenuator 30, not only the same effects as in the optical attenuator 20 shown in FIG. 1 can be obtained, but also by disposing the optical attenuators 5a to 5d in a zigzag manner. The length of the optical attenuator 30 in the propagation direction of the optical signal can be reduced, and the optical attenuator 30 can be smaller than the optical attenuator 30 shown in FIG.
【００３２】本光減衰器は、波長多重伝送方式（Ｗａｖ
ｅｌｅｎｇｔｈ ＤｉｖｉｓｉｏｎＭｕｌｔｉ／Ｄｅｍ
ｕｌｔｉｐｌｅｘｅｒ、ＷＤＭ）で各波長毎の強度を調
節することによってチャネル毎の光強度をイコライズさ
せることができる。[0032] This optical attenuator, wavelength multiplex transmission method (W av
elength D ivision M ulti / Dem
The optical intensity for each channel can be equalized by adjusting the intensity for each wavelength with a multiplexer (WDM).
【００３３】以上において、本発明によれば、小型で各
チャネル間のアイソレーションが確実な多チャネル光減
衰器を製作することができる。As described above, according to the present invention, it is possible to manufacture a small-sized multi-channel optical attenuator having a reliable isolation between channels.
【００３４】[0034]
【発明の効果】以上要するに本発明によれば、次のよう
な優れた効果を発揮する。In summary, according to the present invention, the following excellent effects are exhibited.
【００３５】小型で各チャネル間のアイソレーションが
確実な光減衰器の提供を実現することができる。It is possible to provide an optical attenuator which is small in size and ensures isolation between channels.
【図１】本発明の光減衰器の一実施の形態を示す平面図
である。FIG. 1 is a plan view showing an embodiment of an optical attenuator of the present invention.
【図２】図１に示した光減衰器の説明図である。FIG. 2 is an explanatory diagram of the optical attenuator shown in FIG.
【図３】本発明の光減衰器の他の実施の形態を示す平面
図である。FIG. 3 is a plan view showing another embodiment of the optical attenuator of the present invention.
【図４】（ａ）は従来の光減衰器の平面図であり、
（ｂ）は（ａ）のＤ−Ｄ線断面図である。FIG. 4A is a plan view of a conventional optical attenuator,
(B) is a sectional view taken along line DD of (a).
【図５】図４（ａ）に示した光減衰器のＤ−Ｄ線方向の
温度分布を示す図である。FIG. 5 is a diagram showing a temperature distribution in the direction of line DD of the optical attenuator shown in FIG.
４ａ〜４ｈ 金属薄膜ヒータ ５ａ〜５ｄ 光減衰部 ２３、３３ 基板 １１ 入力用光ファイバアレイ １３ 出力用光ファイバアレイ ２１ａ〜２１ｄ、３１ａ〜３１ｄ 入力用光導波路 ２２ａ〜２２ｄ、３２ａ〜３２ｄ 出力用光導波路 ２０、３０ 光減衰器 4a-4h Metal thin-film heaters 5a-5d Light attenuator 23, 33 Substrate 11 Input optical fiber array 13 Output optical fiber array 21a-21d, 31a-31d Input optical waveguide 22a-22d, 32a-32d Output optical waveguide 20, 30 Optical attenuator
Claims (3)
の分岐側間に並列接続され、その並列接続された光導波
路の少なくとも一方に金属薄膜ヒータが取付けられた光
減衰部と、該光減衰部の一方のＹ分岐光導波路の合流側
に接続され光信号が入力される入力用光導波路と、上記
光減衰部の他方のＹ分岐光導波路の合流側に接続され上
記金属薄膜ヒータの通電加熱で生じる屈折率変化に伴う
位相差により光強度が減衰された光信号が出力される出
力用光導波路とが同一基板上に複数組並列に配置された
光減衰器において、各光減衰部が光信号の伝播方向と平
行な方向に位置をずらして配置されていることを特徴と
する光減衰器。An optical attenuator, comprising: a pair of optical waveguides connected in parallel between the branch sides of a pair of Y-branch optical waveguides; and a light-attenuating unit having a metal thin film heater attached to at least one of the parallel-connected optical waveguides. An input optical waveguide connected to the converging side of one of the Y-branch optical waveguides of the attenuator and receiving an optical signal; In an optical attenuator in which a plurality of sets of output optical waveguides that output optical signals whose optical intensities are attenuated by a phase difference due to a change in refractive index caused by heating are arranged in parallel on the same substrate, each optical attenuator is An optical attenuator, wherein the optical attenuator is displaced in a direction parallel to a propagation direction of an optical signal.
入出力用光導波路の間隔Ｂと、各光減衰部間の入出力用
光導波路に沿った方向の間隔ＣとがＡ＜Ｂ＜Ｃとなるよ
うに配置されている請求項１に記載の光減衰器。2. The distance A between the optical waveguides of each light attenuating part, the distance B between the input / output optical waveguides, and the distance C between the light attenuating parts in the direction along the input / output optical waveguide are A. The optical attenuator according to claim 1, wherein the optical attenuator is arranged so that <B <C.
されている請求項１又は２に記載の光減衰器。3. The optical attenuator according to claim 1, wherein each of the optical attenuators is displaced in a zigzag manner.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000370390A JP2002169130A (en) | 2000-12-05 | 2000-12-05 | Optical attenuator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000370390A JP2002169130A (en) | 2000-12-05 | 2000-12-05 | Optical attenuator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002169130A true JP2002169130A (en) | 2002-06-14 |
Family
ID=18840295
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000370390A Pending JP2002169130A (en) | 2000-12-05 | 2000-12-05 | Optical attenuator |
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| Country | Link |
|---|---|
| JP (1) | JP2002169130A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1536275A1 (en) * | 2003-11-25 | 2005-06-01 | Nec Corporation | Multi-channel Mach-Zehnder interferometer type optical circuits with means for restraining heat interference of adjacent channels |
| JP2012103505A (en) * | 2010-11-10 | 2012-05-31 | Nippon Telegr & Teleph Corp <Ntt> | Ganged thermo-optic phase shifter and optical interference circuit using the same |
| WO2019172176A1 (en) * | 2018-03-08 | 2019-09-12 | 日本電信電話株式会社 | Optical switch array and multicast switch |
-
2000
- 2000-12-05 JP JP2000370390A patent/JP2002169130A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1536275A1 (en) * | 2003-11-25 | 2005-06-01 | Nec Corporation | Multi-channel Mach-Zehnder interferometer type optical circuits with means for restraining heat interference of adjacent channels |
| US7228019B2 (en) | 2003-11-25 | 2007-06-05 | Nec Corporation | Multi-channel Mach-Zehnder interferometer type optical circuits for restraining heat interference of adjacent channel |
| CN100338503C (en) * | 2003-11-25 | 2007-09-19 | 日本电气株式会社 | Multi-channel Mach-Zehnder interferometer type optical circuits for restraining heat interference of adjacent channel |
| JP2012103505A (en) * | 2010-11-10 | 2012-05-31 | Nippon Telegr & Teleph Corp <Ntt> | Ganged thermo-optic phase shifter and optical interference circuit using the same |
| WO2019172176A1 (en) * | 2018-03-08 | 2019-09-12 | 日本電信電話株式会社 | Optical switch array and multicast switch |
| JP2019158976A (en) * | 2018-03-08 | 2019-09-19 | 日本電信電話株式会社 | Optical switch array and multicast switch |
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