JP3201554B2 - Crossed optical waveguide - Google Patents
Crossed optical waveguideInfo
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- JP3201554B2 JP3201554B2 JP20605393A JP20605393A JP3201554B2 JP 3201554 B2 JP3201554 B2 JP 3201554B2 JP 20605393 A JP20605393 A JP 20605393A JP 20605393 A JP20605393 A JP 20605393A JP 3201554 B2 JP3201554 B2 JP 3201554B2
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- Prior art keywords
- optical waveguide
- optical
- crossing
- excess loss
- mode
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Description
【０００１】[0001]
【産業上の利用分野】本発明は導波路型光回路に関し、
特に光回路を集積化するために用いられる交差光導波路
に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide type optical circuit,
In particular, the present invention relates to a crossed optical waveguide used for integrating an optical circuit.
【０００２】[0002]
【従来の技術】従来より、光通信や光信号処理のための
光部品として、ＬｉＮｂＯ3 や石英系光導波路を用いた
光分岐器、光スイッチ、光合分波器等が実現されてい
る。また、これらの光回路を構成要素とした１２８ｃｈ
光周波数選択スイッチ、８×８マトリクス・光スイッ
チ、８ｃｈ光周波数合分波器等の大規模な光回路が実現
されてきている（例えば、Opt.Quantum Electron、22,3
91、1990、M.Kawachi 参照）。そして、これらの大規模
な光回路をより高密度に集積化させたり、小規模な光回
路をアレイ状に多数集積化するには交差光導波路を用い
ることが有効である。2. Description of the Related Art Hitherto, as optical components for optical communication and optical signal processing, optical splitters, optical switches, optical multiplexers / demultiplexers, and the like using LiNbO 3 or quartz optical waveguides have been realized. In addition, 128 channels including these optical circuits as constituent elements
Large-scale optical circuits such as an optical frequency selection switch, an 8 × 8 matrix optical switch, and an 8ch optical frequency multiplexer / demultiplexer have been realized (for example, Opt. Quantum Electron, 22, 3).
91, 1990, M. Kawachi). In order to integrate these large-scale optical circuits at a higher density or to integrate a large number of small-scale optical circuits in an array, it is effective to use a crossed optical waveguide.
【０００３】図１は交差光導波路による光回路の集積化
のようすを示すもので、図中、１は基板、２は該基板１
上に光導波路で構成された光回路構成要素、３は該要素
２の入出力端に接続された少なくとも１本の光導波路群
である。ここで、光回路構成要素２が２入力２出力を有
する単一のマッハ・ツェンダ光干渉計で構成された光合
分波器であるとすると、光導波路群３は２本程度の光導
波路である。FIG. 1 shows how an optical circuit is integrated by means of a crossed optical waveguide. In FIG.
The optical circuit component 3 composed of an optical waveguide above is at least one optical waveguide group connected to the input / output end of the component 2. Here, assuming that the optical circuit component 2 is an optical multiplexer / demultiplexer constituted by a single Mach-Zehnder optical interferometer having two inputs and two outputs, the optical waveguide group 3 is about two optical waveguides. .
【０００４】図１(a) は交差光導波路を用いない場合の
回路構成を示すものであるが、図１(b) に示すように交
差光導波路４を用いることにより集積密度を約２倍にで
き、また、図１(c) に示すように交差光導波路部５ａ，
５ｂを用いることによりアレイ状に多数集積化できる。FIG. 1A shows a circuit configuration in the case where the crossed optical waveguide is not used. As shown in FIG. 1B, the use of the crossed optical waveguide 4 doubles the integration density. As shown in FIG. 1 (c), the crossed optical waveguides 5a,
By using 5b, many can be integrated in an array.
【０００５】しかしながら、一般に、光導波路は交差さ
せると過剰損失を生じる。従って、光回路構成要素２自
体の過剰損失が所要値以下であったとしても、交差光導
波路４や交差光導波路部５ａ，５ｂでの過剰損失がそれ
らに比べて大きければ、回路特性を劣化させることにな
る。特に、交差数が増えるほど過剰損失は増加し、回路
特性への影響を十分考慮する必要がでてくる。However, in general, crossing optical waveguides causes excessive loss. Therefore, even if the excess loss of the optical circuit component 2 itself is equal to or less than a required value, if the excess loss in the crossed optical waveguide 4 and the crossed optical waveguide portions 5a and 5b is larger than those, circuit characteristics are deteriorated. Will be. In particular, the excess loss increases as the number of intersections increases, and it is necessary to sufficiently consider the influence on circuit characteristics.
【０００６】前記過剰損失はその光導波路の構造、即ち
コアとクラッドの比屈折率差やコア径等に依存する。ま
た、光導波路の交差角にも依存することは良く知られ、
一般に、交差角が大きくなるほど交差光導波路の過剰損
失は減少する。このように、所要の回路特性が最小交差
角を制限し、該最小交差角が設計の自由度を制限し、結
果として光回路の集積度を制限することになる。The excess loss depends on the structure of the optical waveguide, that is, the relative refractive index difference between the core and the clad, the core diameter, and the like. It is also well known that it depends on the crossing angle of the optical waveguide.
In general, as the crossing angle increases, the excess loss of the crossing optical waveguide decreases. Thus, the required circuit characteristics limit the minimum crossing angle, which limits the degree of freedom in design and consequently the degree of integration of the optical circuit.
【０００７】図２は導波路型光回路に含まれる交差光導
波路の一例を示すもので、図中、１１はシリコン基板、
１２はシリコン基板１１上に形成された第１の石英系光
導波路、１３はシリコン基板１１上に形成されたＮ本の
第２の石英系光導波路である。ここで、光導波路１２，
１３はその高さＨ、幅Ｗ、コアとクラッドの比屈折率差
Δが同一であり、各光導波路１３は光導波路１２に対し
て交差角θ及び隣接する光導波路間の間隔ｌで交差して
いるものとする。FIG. 2 shows an example of a crossed optical waveguide included in a waveguide type optical circuit, in which 11 is a silicon substrate,
Reference numeral 12 denotes a first quartz optical waveguide formed on the silicon substrate 11, and reference numeral 13 denotes N second quartz optical waveguides formed on the silicon substrate 11. Here, the optical waveguide 12,
13 have the same height H, width W, and relative refractive index difference Δ between the core and the cladding, and each optical waveguide 13 intersects the optical waveguide 12 at an intersection angle θ and an interval 1 between adjacent optical waveguides. It is assumed that
【０００８】図２の交差光導波路において、間隔ｌを光
ファイバアレイと光回路との接続を考慮した間隔、即ち
一般に用いられている光ファイバアレイのファイバ間隔
である２５０μｍとした場合の交差角θ（１０度〜９０
度）に対する波長１．３１μｍのＴＥ及びＴＭモード並
びに１．５５μｍのＴＥ及びＴＭモードの光の過剰損失
を図３、図４に示す。In the crossed optical waveguide shown in FIG. 2, the intersecting angle θ is set when the interval 1 is set to the interval considering the connection between the optical fiber array and the optical circuit, that is, 250 μm, which is the fiber interval of a commonly used optical fiber array. (10 degrees to 90
The excess loss of 1.31 μm wavelength TE and TM mode and 1.55 μm TE and TM mode light with respect to (degree) is shown in FIGS.
【０００９】図３はＨ＝８μｍ、Ｗ＝８μｍ、Δ＝０．
３％、即ち単一モード光導波路の場合の例であり、Ｎ＝
１００、過剰損失は一交差当りの値で示している。例え
ば、θ＝３０度では一交差当りの過剰損失は約０．０５
ｄＢであるが、交差数Ｎ＝１００では約５ｄＢとなり、
この交差光導波路では約３２％しか透過しない。θ＝６
０度にすると、Ｎ＝１００での過剰損失は約１ｄＢとな
り、約７９％透過させることができる。FIG. 3 shows H = 8 μm, W = 8 μm, Δ = 0.
3%, ie, an example of a single mode optical waveguide, where N =
100, excess loss is shown as a value per cross. For example, at θ = 30 degrees, the excess loss per intersection is about 0.05
It is about 5 dB when the number of intersections N = 100.
Only about 32% is transmitted through this crossed optical waveguide. θ = 6
At 0 degrees, the excess loss at N = 100 is about 1 dB, allowing about 79% transmission.
【００１０】また、図４はＨ＝７μｍ、Ｗ＝６．５μ
ｍ、Δ＝０．７５％、即ち疑似単一モード光導波路の場
合の例であり、Ｎ＝１００、過剰損失は一交差当りの値
で示している。比屈折率差Δを大きくすると、同じ交差
角θでも過剰損失が大きくなることがわかる。例えば、
θ＝３０度では一交差当りの過剰損失は約０．３ｄＢで
あるが、Ｎ＝１００では約３０ｄＢとなり、約０．１％
しか透過しないことになる。θ＝６０度にすると、Ｎ＝
１００での過剰損失は約４ｄＢであり、約４０％透過さ
せることができる。また、Ｎ＝２５にすると過剰損失を
約１ｄＢにでき、約７９％透過させることができる。即
ち、過剰損失を許容値以下にするためには、最小交差角
や交差数を制限する必要がある。FIG. 4 shows H = 7 μm and W = 6.5 μm.
m, Δ = 0.75%, that is, an example of a quasi-single-mode optical waveguide, where N = 100, and excess loss is shown as a value per cross. It can be seen that when the relative refractive index difference Δ is increased, the excess loss increases even at the same intersection angle θ. For example,
When θ = 30 degrees, the excess loss per crossing is about 0.3 dB, but when N = 100, it becomes about 30 dB, which is about 0.1%.
Will only be transmitted. When θ = 60 degrees, N =
The excess loss at 100 is about 4 dB, which allows about 40% transmission. When N = 25, the excess loss can be reduced to about 1 dB, and about 79% of the light can be transmitted. That is, it is necessary to limit the minimum intersection angle and the number of intersections in order to reduce the excess loss to an allowable value or less.
【００１１】また、交差光導波路の過剰損失は、交差部
での光導波路の比屈折率差Δを小さくする、幅Ｗを広げ
る、高さＨを高くする等により低減することもできる
（例えば、in Tech.Dig.OEC'92、16B4-1、1992、T.Komi
nato et al.,参照）。The excess loss of the crossed optical waveguide can also be reduced by reducing the relative refractive index difference Δ of the optical waveguide at the crossing portion, increasing the width W, increasing the height H, and the like (for example, in Tech.Dig.OEC'92, 16B4-1, 1992, T.Komi
nato et al., see).
【００１２】[0012]
【発明が解決しようとする課題】前述したように、過剰
損失を所要値以下にするためには、交差角を一定の角度
以上にするか、交差数を一定数以下にする必要がある。
それゆえ、交差数が増すほど最小交差角は大きくなり、
設計の自由度が減り、集積度を上げることができなくな
るという問題があった。As described above, in order to reduce the excess loss to a required value or less, it is necessary to set the intersection angle to a certain angle or more, or to make the number of intersections a certain number or less.
Therefore, as the number of intersections increases, the minimum intersection angle increases,
There is a problem that the degree of freedom in design is reduced and the degree of integration cannot be increased.
【００１３】また、前述したように、交差部での光導波
路の比屈折率差を小さくする、幅を広げる、高さを高く
する等により過剰損失を調整することもできるが、比屈
折率差を下げたり、高さを高くすることは作製プロセス
を複雑にすることになり、特に、これらの調整を所望の
位置の数１００μｍ程度の領域で高精度に行うことは、
作製プロセスをより複雑にするという問題があった。ま
た、損失が生じないように比屈折率差、幅、高さ等を所
望の値に調整するにはこれらを十分なだらかに変化させ
る必要があり、この調整のための領域が必要となり、集
積度を制限することになるという問題があった。さらに
この場合、交差数が増すほど比屈折率差、幅、高さ等を
大きく変える必要があり、その分、前記調整のための領
域が大きくなり、集積度をより制限することになるとい
う問題があった。Further, as described above, excess loss can be adjusted by reducing the relative refractive index difference of the optical waveguide at the intersection, increasing the width, increasing the height, and the like. Decreasing the height or increasing the height complicates the manufacturing process. In particular, performing these adjustments with high accuracy in a desired position in a region of about several hundred μm is difficult.
There was a problem that the manufacturing process became more complicated. Further, in order to adjust the relative refractive index difference, width, height, and the like to desired values so that no loss occurs, it is necessary to change these gently enough, and an area for this adjustment is required, and the There was a problem that would be limited. Further, in this case, as the number of intersections increases, the relative refractive index difference, the width, the height, and the like need to be greatly changed, and accordingly, the area for the adjustment increases, and the degree of integration is further limited. was there.
【００１４】本発明は前記従来の問題点に鑑み、交差部
での光導波路の構造を変えることなく、最小交差角を小
さくでき、しかも交差数を多くなし得る低損失な交差光
導波路を提供することを目的とする。The present invention has been made in view of the above-mentioned conventional problems, and provides a low-loss crossed optical waveguide capable of reducing the minimum crossing angle and increasing the number of crossings without changing the structure of the optical waveguide at the crossing portion. The purpose is to:
【００１５】[0015]
【課題を解決するための手段】本発明では前記目的を達
成するため、一の基板上に形成された比屈折率差が３％
以下の単一モードあるいは疑似単一モード光導波路より
なる第１の光導波路と、該第１の光導波路に交差する如
く前記一の基板上に形成された少なくとも３本の比屈折
率差が３％以下の単一モードあるいは疑似単一モード光
導波路よりなる第２の光導波路とで構成され、前記第１
の光導波路と第２の光導波路の交差部のうち少なくとも
１つは交差角が９０°未満である交差光導波路におい
て、前記交差部は等しい間隔で配置され、その間隔を３
０μｍ〜１５０μｍとした交差光導波路を提案する。According to the present invention, in order to achieve the above object, the relative refractive index difference formed on one substrate is 3%.
A first optical waveguide comprising the following single mode or pseudo single mode optical waveguide, and at least three relative refractive index differences formed on the one substrate so as to intersect the first optical waveguide are 3 % Or less of a single mode or pseudo single mode optical waveguide .
At least the intersection of the optical waveguide and the second optical waveguide
One is that in an intersection optical waveguide having an intersection angle of less than 90 °, the intersections are arranged at equal intervals, and the interval is set to 3
A crossed optical waveguide having a thickness of 0 μm to 150 μm is proposed.
【００１６】[0016]
【作用】本発明によれば、交差部での交差間隔を限定す
るのみで過剰損失を低減できるので、最小交差角を小さ
く構成することができ、光回路の集積度を上げることが
できる。また、光導波路の構造を変える必要がないの
で、作製プロセスを複雑にしたり、光導波路の構造を変
えることによる過剰損失を生じさせることもない。ま
た、光導波路の構造を変える領域を必要としないことか
ら、より高集積化が図れる。According to the present invention, since the excess loss can be reduced only by limiting the crossing interval at the crossing portion, the minimum crossing angle can be reduced, and the degree of integration of the optical circuit can be increased. Further, since it is not necessary to change the structure of the optical waveguide, there is no need to complicate the manufacturing process or to cause excessive loss due to changing the structure of the optical waveguide. Further, since a region for changing the structure of the optical waveguide is not required, higher integration can be achieved.
【００１７】[0017]
【実施例１】本実施例の交差光導波路の構造は図２に示
したものと同一であり、ここで、高さＨを８μｍ、幅Ｗ
を８μｍ、比屈折率差Δを０．３％とした石英系単一モ
ード光導波路を光導波路１２，１３に用い、交差角θを
３０度、交差数Ｎを５０とし、交差間隔ｌを５０μｍと
したところ、交差による過剰損失は約０．２ｄＢとな
り、９５％透過させることができた。Embodiment 1 The structure of the crossed optical waveguide of this embodiment is the same as that shown in FIG. 2, where the height H is 8 μm and the width W is
8 μm, and a silica-based single mode optical waveguide having a relative refractive index difference Δ of 0.3% is used for the optical waveguides 12 and 13, the intersection angle θ is 30 degrees, the number of intersections N is 50, and the intersection interval 1 is 50 μm. As a result, the excess loss due to the intersection was about 0.2 dB, and 95% transmission was possible.
【００１８】前記構成において、交差間隔ｌ（８μｍ〜
２０００μｍ）に対する波長１．３１μｍのＴＥ及びＴ
Ｍモード並びに１．５５μｍのＴＥ及びＴＭモードの光
の過剰損失を図５に示す。なお、ここでは交差間隔ｌに
対する過剰損失の変化を分かり易くするために１．５５
μｍのＴＥモードでの実測値を実線で結んである。ま
た、過剰損失は一交差当りの損失値で示してある。In the above structure, the crossing interval l (8 μm to
1.3 μm TE and T for 2000 μm)
FIG. 5 shows the excess loss of light in the M mode and the 1.55 μm TE and TM modes. Here, in order to make it easy to understand the change of the excess loss with respect to the intersection distance l, 1.55
The measured value in μm TE mode is connected by a solid line. The excess loss is indicated by a loss value per intersection.
【００１９】図６は図５の一部拡大図であり、交差間隔
ｌが２００μｍ以下での過剰損失を示す。交差間隔ｌを
３０μｍ〜１５０μｍにすれば、一交差当りの過剰損失
を０．０２５ｄＢ以下、即ち従来の交差光導波路の過剰
損失の約１／２程度にでき、実用上は十分である。特
に、交差間隔ｌを３０μｍ〜１３０μｍにすれば、一交
差当りの過剰損失を０．０２ｄＢ以下にでき、さらに交
差間隔ｌを３０μｍ〜１００μｍにすれば、一交差当り
の過剰損失を０．０１ｄＢ以下にできることが分かる。FIG. 6 is a partially enlarged view of FIG. 5, and shows an excess loss when the intersecting interval 1 is 200 μm or less. If the crossing interval 1 is 30 μm to 150 μm, the excess loss per crossing can be 0.025 dB or less, that is, about 1/2 of the excess loss of the conventional crossing optical waveguide, which is practically sufficient. In particular, if the crossing interval 1 is 30 μm to 130 μm, the excess loss per crossing can be 0.02 dB or less, and if the crossing interval 1 is 30 μm to 100 μm, the excess loss per crossing is 0.01 dB or less. You can see that you can do it.
【００２０】[0020]
【実施例２】本実施例の交差光導波路の構造は図２に示
したものと同一であり、ここで、高さＨを７μｍ、幅Ｗ
を６．５μｍ、比屈折率差Δを０．７５％とした石英系
疑似単一モード光導波路を光導波路１２，１３に用い、
交差角θを３０度、交差数Ｎを１００とし、交差間隔ｌ
を５０μｍとしたところ、交差による過剰損失は約０．
８ｄＢとなり、８３％透過させることができた。Embodiment 2 The structure of the crossed optical waveguide of this embodiment is the same as that shown in FIG. 2, where the height H is 7 μm and the width W is
Is used for the optical waveguides 12 and 13 using a quartz-based pseudo single-mode optical waveguide having a refractive index difference of 6.5 μm and a relative refractive index difference Δ of 0.75%.
The intersection angle θ is 30 degrees, the number of intersections N is 100, and the intersection interval l
Is set to 50 μm, the excess loss due to crossing is about 0.
8 dB, and 83% transmission was possible.
【００２１】前記構成において、交差間隔ｌ（６．５μ
ｍ〜２０００μｍ）に対する波長１．３１μｍのＴＥ及
びＴＭモード並びに１．５５μｍのＴＥ及びＴＭモード
の光の過剰損失を図７に示す。なお、ここでは交差間隔
ｌに対する過剰損失の変化を分かり易くするために１．
５５μｍのＴＥモードでの実測値を実線で結んである。
また、過剰損失は一交差当りの損失値で示してある。In the above configuration, the crossing interval l (6.5 μ
The excess loss of 1.31 μm wavelength TE and TM modes and 1.55 μm TE and TM modes of light for m-2000 μm) is shown in FIG. Here, in order to make it easy to understand the change of the excess loss with respect to the intersecting interval l, 1.
The measured values in the 55 μm TE mode are connected by solid lines.
The excess loss is indicated by a loss value per intersection.
【００２２】図８は図７の一部拡大図であり、交差間隔
ｌが２００μｍ以下での過剰損失を示す。交差間隔ｌを
３０μｍ〜１５０μｍにすれば、一交差当りの過剰損失
を０．２ｄＢ以下、即ち従来の交差光導波路の過剰損失
以下にできる。特に、交差間隔ｌを３０μｍ〜１３０μ
ｍにすれば、一交差当りの過剰損失を０．１ｄＢ以下、
即ち従来の交差光導波路の過剰損失の約１／２程度にで
き、さらに交差間隔ｌを３０μｍ〜１００μｍにすれ
ば、一交差当りの過剰損失を０．０５ｄＢ以下にできる
ことが分かる。FIG. 8 is a partially enlarged view of FIG. 7, and shows an excess loss when the intersecting distance 1 is 200 μm or less. If the crossing interval 1 is 30 μm to 150 μm, the excess loss per crossing can be 0.2 dB or less, that is, the excess loss of the conventional crossing optical waveguide. In particular, the crossing interval l is set to 30 μm to 130 μm.
m, the excess loss per crossing is 0.1 dB or less,
That is, it can be seen that the excess loss per cross can be reduced to 0.05 dB or less if the excess loss of the conventional crossed optical waveguide can be reduced to about 1/2 and the crossing interval l is set to 30 μm to 100 μm.
【００２３】このように、比屈折率差Δが３％までの単
一モードあるいは疑似単一モード光導波路を用いた交差
光導波路では、交差間隔ｌを３０μｍ〜１５０μｍにす
ることにより、一交差当りの過剰損失を従来の交差光導
波路以下にできる。特に、損失をより小さくするには、
交差間隔ｌを３０μｍ〜１００μｍにすることが望まし
い。As described above, in a crossed optical waveguide using a single-mode or quasi-single-mode optical waveguide having a relative refractive index difference Δ of up to 3%, by setting the crossing interval l to 30 μm to 150 μm, In excess of the conventional crossed optical waveguide. In particular, to make the loss smaller,
It is desirable that the intersecting interval 1 be 30 μm to 100 μm.
【００２４】前記実施例１，２における光導波路１２，
１３は、１．３１μｍ及び１．５５μｍで１次モードを
伝搬できる２モード光導波路であるが、光回路を構成す
る上では単一モード光導波路と同様に扱える疑似単一モ
ード光導波路である。しかしながら、２モード光導波路
であるため、大きな光の蛇行が生じ易く、交差間隔ｌが
２００μｍ以上において、図７に見られるように蛇行周
期とほぼ同じ周期の損失変動が生じている。交差間隔ｌ
＝２００μｍ以上で交差光導波路を構成する場合は、過
剰損失が小さくなる交差間隔ｌを設定することが望まし
い。また、過剰損失が小さくなる交差間隔ｌは光の波長
により若干異なるので、これを考慮する必要がある。In the first and second embodiments, the optical waveguides 12 and
Reference numeral 13 denotes a two-mode optical waveguide that can propagate a first-order mode at 1.31 μm and 1.55 μm, but is a pseudo single-mode optical waveguide that can be treated in the same manner as a single-mode optical waveguide in forming an optical circuit. However, since it is a two-mode optical waveguide, large meandering of light is likely to occur, and when the crossing interval l is 200 μm or more, a loss fluctuation having a cycle substantially equal to the meandering cycle occurs as shown in FIG. Intersection interval l
In the case where a crossed optical waveguide is formed at a distance of 200 μm or more, it is desirable to set a crossing interval 1 at which excess loss is reduced. Further, since the crossing interval l at which the excess loss becomes small differs slightly depending on the wavelength of light, it is necessary to consider this.
【００２５】なお、「疑似単一モード光導波路」とは、
基本モード（０次モード）ばかりでなく１次モード以上
のモードをも伝搬できる光導波路のうち、光回路を構成
する上で「単一モード光導波路」として扱える光導波路
であり、主に１次〜２次モードまで伝搬できる光導波路
を示している。また、３次モード以上の高次モードまで
伝搬できる光導波路においても、交差間隔ｌには本発明
と同様な適切な値が存在する。The “quasi-single-mode optical waveguide” is
Among the optical waveguides that can propagate not only the fundamental mode (0th-order mode) but also the first-order mode or higher, the optical waveguide can be treated as a “single-mode optical waveguide” in forming an optical circuit, and is mainly a primary mode. 1 shows an optical waveguide that can propagate up to the second mode. Also, in an optical waveguide capable of propagating to a third-order mode or higher mode, an appropriate value similar to that of the present invention is present in the intersecting interval l.
【００２６】また、前記実施例では直線導波路と直線導
波路との交差の場合を示したが、これに限定されるもの
ではなく、曲げ導波路と直線導波路との交差、曲げ導波
路と曲げ導波路との交差も本発明の対象である。Further, in the above-described embodiment, the case where the straight waveguide intersects with the straight waveguide is shown. However, the present invention is not limited to this. Intersection with bent waveguides is also an object of the present invention.
【００２７】また、前記実施例では交差角θを３０度と
したが、これに限定されるものではなく、交差角θが数
度〜９０度のものが本発明の対象である。但し、交差角
θが数度程度の場合、交差した光導波路への光結合割合
が大きくなることから、前述した実施例ほどの過剰損失
の低減は期待できない。In the above embodiment, the crossing angle θ is set to 30 degrees. However, the present invention is not limited to this, and the object of the present invention is that the crossing angle θ is several degrees to 90 degrees. However, when the crossing angle θ is about several degrees, the ratio of light coupling to the crossed optical waveguides becomes large, so that the reduction of excess loss as in the above-described embodiment cannot be expected.
【００２８】また、前記実施例では各光導波路１３の光
導波路１２への交差角θが同一の場合を示したが、ある
程度の範囲内で交差角θが異なっていても本発明は適用
可能である。また、前記実施例では交差光導波路が同一
平面内にある場合を示したが、３次元的に交差し、その
あおり角ψがある程度の範囲内で異なっていても本発明
は適用可能である。In the above embodiment, the case where the crossing angle θ of each optical waveguide 13 with respect to the optical waveguide 12 is the same is shown. However, the present invention is applicable even if the crossing angle θ differs within a certain range. is there. In the above-described embodiment, the case where the crossing optical waveguides are in the same plane is shown. However, the present invention is applicable even if they cross three-dimensionally and their tilt angles 異 な っ differ within a certain range.
【００２９】また、前記実施例では交差部の光導波路の
構造をそれ以外の光回路と同じ構造としたが、交差部の
光導波路の比屈折率差を下げる、幅を広げる、高さを高
くする等の過剰損失を低減する構成と本発明を組み合わ
せても良く、特に、交差角が小さい場合に有効である。In the above embodiment, the structure of the optical waveguide at the intersection is the same as that of the other optical circuit. However, the relative refractive index difference of the optical waveguide at the intersection is reduced, the width is increased, and the height is increased. The present invention may be combined with a configuration for reducing excess loss, such as the case where the crossing angle is small.
【００３０】また、前記実施例ではコア形状を矩形とし
たが、この形状に限定されるものではなく、重要なのは
その電界分布であって、本請求範囲内の比屈折率差で単
一モードあるいは疑似単位モードとなる光導波路であれ
ば良く、例えばコア形状は円形でも良い。In the above embodiment, the core shape is rectangular. However, the shape is not limited to the rectangular shape, but what is important is the electric field distribution. It is sufficient if the optical waveguide is a pseudo unit mode, and for example, the core shape may be circular.
【００３１】また、前記実施例では交差光導波路を光回
路構成要素と分離したが、これに限定されるものではな
く、光回路構成要素内に交差光導波路がある場合も本発
明の対象である。In the above embodiment, the crossed optical waveguide is separated from the optical circuit component. However, the present invention is not limited to this, and the case where the crossed optical waveguide is included in the optical circuit component is also an object of the present invention. .
【００３２】さらにまた、前記実施例では、光導波路と
してシリコン基板上に形成された石英系単一モード光導
波路及び石英系疑似単一モード光導波路を用いたが、こ
れに限定されるものではなく、他の材料系の光導波路、
例えば多成分ガラス基板やニオブ酸リチウム結晶基板上
に金属イオン拡散技術により形成したイオン拡散光導波
路等も本発明の適応対象である。Furthermore, in the above-described embodiment, the quartz single mode optical waveguide and the quartz pseudo single mode optical waveguide formed on the silicon substrate are used as the optical waveguide, but the present invention is not limited to this. , Other material-based optical waveguides,
For example, an ion diffusion optical waveguide formed by a metal ion diffusion technique on a multi-component glass substrate or a lithium niobate crystal substrate is also applicable to the present invention.
【００３３】[0033]
【発明の効果】以上説明したように本発明によれば、一
の基板上に形成された比屈折率差が３％以下の単一モー
ドあるいは疑似単一モード光導波路よりなる第１の光導
波路と、該第１の光導波路に交差する如く前記一の基板
上に形成された少なくとも３本の比屈折率差が３％以下
の単一モードあるいは疑似単一モード光導波路よりなる
第２の光導波路とで構成され、前記第１の光導波路と第
２の光導波路の交差部のうち少なくとも１つは交差角が
９０°未満である交差光導波路において、前記交差部は
等しい間隔で配置され、その間隔を３０μｍ〜１５０μ
ｍとしたため、小さい交差角でも低過剰損失にでき、光
回路の高集積化が図れ、製品を小型化できる。また、高
集積化が図れることにより、従来の光回路の作製プロセ
スにて、より大規模な光回路を作製できる等の利点があ
る。As described above, according to the present invention, a first optical waveguide formed of a single mode or pseudo single mode optical waveguide having a relative refractive index difference of 3% or less formed on one substrate. And a second optical waveguide comprising at least three single-mode or quasi-single-mode optical waveguides having a relative refractive index difference of 3% or less formed on the one substrate so as to intersect with the first optical waveguide. A first optical waveguide and a second optical waveguide.
At least one of the intersections of the two optical waveguides has an intersection angle of
In a crossed optical waveguide that is less than 90 °, the intersection is
It is arranged at equal intervals, and the interval is 30 μm to 150 μm.
m, the excess loss can be reduced even at a small intersection angle, the optical circuit can be highly integrated, and the product can be downsized. In addition, by achieving high integration, there is an advantage that a larger-scale optical circuit can be manufactured by a conventional optical circuit manufacturing process.
【図１】交差光導波路による光回路の集積化のようすを
示す模式図FIG. 1 is a schematic diagram showing how an optical circuit is integrated by a crossed optical waveguide.
【図２】交差光導波路の一例を示す構成図FIG. 2 is a configuration diagram illustrating an example of a crossed optical waveguide;
【図３】図２に示した交差光導波路を単一モード光導波
路で交差間隔２５０μｍとして構成した場合の交差角に
対する過剰損失を示す図FIG. 3 is a diagram showing excess loss with respect to the crossing angle when the crossing optical waveguide shown in FIG. 2 is configured by a single mode optical waveguide with a crossing interval of 250 μm.
【図４】図２に示した交差光導波路を疑似単一モード光
導波路で交差間隔２５０μｍとして構成した場合の交差
角に対する過剰損失を示す図FIG. 4 is a diagram showing excess loss with respect to a crossing angle when the crossing optical waveguide shown in FIG. 2 is configured with a crossing interval of 250 μm using a pseudo single mode optical waveguide.
【図５】図２に示した交差光導波路を単一モード光導波
路で交差角３０度として構成した場合の交差間隔に対す
る過剰損失を示す図FIG. 5 is a diagram showing excess loss with respect to an intersecting interval when the intersecting optical waveguide shown in FIG. 2 is configured by a single mode optical waveguide with an intersecting angle of 30 degrees.
【図６】図５の一部拡大図FIG. 6 is a partially enlarged view of FIG. 5;
【図７】図２に示した交差光導波路を疑似単一モード光
導波路で交差角３０度として構成した場合の交差間隔に
対する過剰損失を示す図FIG. 7 is a diagram showing excess loss with respect to an intersecting interval when the intersecting optical waveguide shown in FIG. 2 is configured with an intersecting angle of 30 degrees using a pseudo single mode optical waveguide.
【図８】図７の一部拡大図8 is a partially enlarged view of FIG. 7;
１１…シリコン基板、１２…第１の石英系光導波路、１
３…第２の石英系光導波路。11 silicon substrate, 12 first quartz optical waveguide, 1
3. Second silica-based optical waveguide.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 加藤 勝己 東京都千代田区内幸町１丁目１番６号 日本電信電話株式会社内 (56)参考文献 特開 平５−80362（ＪＰ，Ａ) 特開 平４−102806（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G02B 6/12 - 6/14 ＪＩＣＳＴファイル（ＪＯＩＳ)──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Katsumi Kato 1-6-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-5-80362 (JP, A) 4-102806 (JP, A) (58) Field surveyed (Int. Cl. 7 , DB name) G02B 6/12-6/14 JICST file (JOIS)
Claims (1)
％以下の単一モードあるいは疑似単一モード光導波路よ
りなる第１の光導波路と、該第１の光導波路に交差する
如く前記一の基板上に形成された少なくとも３本の比屈
折率差が３％以下の単一モードあるいは疑似単一モード
光導波路よりなる第２の光導波路とで構成され、前記第
１の光導波路と第２の光導波路の交差部のうち少なくと
も１つは交差角が９０°未満である交差光導波路におい
て、前記交差部は等しい間隔で配置され、その 間隔を３０μ
ｍ〜１５０μｍとしたことを特徴とする交差光導波路。A relative refractive index difference formed on one substrate is 3
% Of a single-mode or pseudo-single-mode optical waveguide having a relative refractive index difference of at least three formed on the one substrate so as to intersect the first optical waveguide. 3% or less of a single-mode or quasi-single-mode optical waveguide .
At least the intersection of the first optical waveguide and the second optical waveguide
Another is a crossed optical waveguide having a crossing angle of less than 90 ° , wherein the crossing portions are arranged at equal intervals, and the interval is set to 30 μm.
A crossed optical waveguide having a diameter of from about m to about 150 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20605393A JP3201554B2 (en) | 1993-08-20 | 1993-08-20 | Crossed optical waveguide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20605393A JP3201554B2 (en) | 1993-08-20 | 1993-08-20 | Crossed optical waveguide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0756034A JPH0756034A (en) | 1995-03-03 |
| JP3201554B2 true JP3201554B2 (en) | 2001-08-20 |
Family
ID=16517096
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20605393A Expired - Lifetime JP3201554B2 (en) | 1993-08-20 | 1993-08-20 | Crossed optical waveguide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3201554B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2056493A1 (en) | 2005-08-31 | 2009-05-06 | Fujitsu Limited | Differential multilevel modulated optical signal receiver apparatus |
| US7776651B2 (en) | 2003-03-31 | 2010-08-17 | Intel Corporation | Method for compensating for CTE mismatch using phase change lead-free super plastic solders |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6668107B2 (en) * | 2001-12-21 | 2003-12-23 | Agilent Technologies, Inc. | Method and apparatus for reducing optical insertion loss in planar lightwave circuits through dielectric perturbation optimization |
| JP5440660B2 (en) * | 2012-06-18 | 2014-03-12 | 沖電気工業株式会社 | Optical waveguide device |
-
1993
- 1993-08-20 JP JP20605393A patent/JP3201554B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7776651B2 (en) | 2003-03-31 | 2010-08-17 | Intel Corporation | Method for compensating for CTE mismatch using phase change lead-free super plastic solders |
| EP2056493A1 (en) | 2005-08-31 | 2009-05-06 | Fujitsu Limited | Differential multilevel modulated optical signal receiver apparatus |
| US7613403B2 (en) | 2005-08-31 | 2009-11-03 | Fujitsu Limited | Differential multilevel modulated optical signal receiver apparatus |
| US8509628B2 (en) | 2005-08-31 | 2013-08-13 | Fujitsu Limited | Differential multilevel modulated optical signal receiver apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0756034A (en) | 1995-03-03 |
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