JPH02244105A - Waveguide type diffraction grating - Google Patents
Waveguide type diffraction gratingInfo
- Publication number
- JPH02244105A JPH02244105A JP6558889A JP6558889A JPH02244105A JP H02244105 A JPH02244105 A JP H02244105A JP 6558889 A JP6558889 A JP 6558889A JP 6558889 A JP6558889 A JP 6558889A JP H02244105 A JPH02244105 A JP H02244105A
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- dimensional
- waveguide
- waveguides
- dimensional waveguide
- diffraction grating
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- 239000000758 substrate Substances 0.000 abstract description 12
- 230000004304 visual acuity Effects 0.000 abstract 2
- 230000003287 optical effect Effects 0.000 description 13
- 230000008878 coupling Effects 0.000 description 7
- 238000010168 coupling process Methods 0.000 description 7
- 238000005859 coupling reaction Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
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- 230000005855 radiation Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
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Abstract
Description
【発明の詳細な説明】
「産業上の利用分野」
本発明は、優れた分解能および高い回折効率を有する導
波路形回折格子に関するものである。DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a waveguide-type diffraction grating having excellent resolution and high diffraction efficiency.
「従来の技術」
近年、波長分割多重伝送システムにおいて、多重度を増
やし伝送量を増大させようという試みがなされている。"Prior Art" In recent years, attempts have been made to increase the degree of multiplexing and increase the amount of transmission in wavelength division multiplexing transmission systems.
これを実現するには波長間隔の小さい光を分波できる分
波器が必要であるが、従来の回折格子を用いた分波器で
は、分解能を上げるために回折次数の高い回折・光を用
いると、回折効率が低下するという欠点があった。これ
を回避する有用な方法の１つとして、複数の同心円弧上
に配置された三次元導波路により、回折格子の機能を持
たせる方法が知られている（’Ｎｅｗ ｆｏｃｕｓｉｎ
ｇａｎｄ ｄｉｓｐｅｒｓｉｖｅ ｐｌａｎａｒ
ｃｏｍｐｏｎｅｎｔ ｂａｓｅｄ ｏｎ ａｎ
ｏｐｔｉｃａｌ ｐｈａｓｅｄ ａｒｒａｙ ： Ｍ、
に、５ｓｉｔ＋ ＥｌｅｃｔｒｏｎｉｃｓＬｅｔｔｅｒ
ｓ、 Ｖｏｌ、２４． ｐｐ、３８５−３８６．１９８
８．） 。同論文の方法においては、回折角θ、導波路
間隔ΔＲ１円弧の開き角φ、二次元導波路の等側屈折率
ｎ１、三次元導波路の等側屈折率ｎｃ、回折次数ｍ、真
空中での波長λは次式の関係にある。To achieve this, a demultiplexer capable of demultiplexing light with small wavelength intervals is required, but conventional demultiplexers using diffraction gratings use diffraction/light with a high diffraction order to increase resolution. However, there was a drawback that the diffraction efficiency decreased. One useful method to avoid this is to use three-dimensional waveguides arranged on multiple concentric arcs to function as a diffraction grating ('New focus').
gand dispersive planar
component based on an
Optical phased array: M,
5sit+ Electronics Letter
s, Vol, 24. pp, 385-386.198
8. ). In the method of the same paper, the diffraction angle θ, the waveguide spacing ΔR1, the arc opening angle φ, the isolateral refractive index n1 of the two-dimensional waveguide, the isolateral refractive index nc of the three-dimensional waveguide, the diffraction order m, and in vacuum The wavelength λ of is in the following relationship.
ｎ、ΔＲ５１ｎθ＋ｎ、、φΔＲ＝ｍλ ・（、ｌ
）中心波長λ。の近傍においてはθ＝０であり、このと
き回折次数ｍは次式で与えられる。n, ΔR51nθ+n,, φΔR=mλ ・(, l
) center wavelength λ. In the vicinity of , θ=0, and in this case, the diffraction order m is given by the following equation.
□＝ 」−逆」」− λ。□＝ ”−Reverse””− λ.
・・・（２）
従って、分解可能最小波長間隔Δλは、導波路数をＮと
して、次式で与えられる。(2) Therefore, the minimum resolvable wavelength interval Δλ is given by the following equation, where N is the number of waveguides.
Δλ＝ １° ＝ １° ・・（３）Ｎ
ｍ ｎ ｃφＮΔＲ
上式（３）において、導波路数Ｎと導波路間隔ΔＲの積
ＮΔＲは、およそその導波路形回折格子の横幅を示すも
ので、その大きさは導波路を形成する基板の大きさに制
限される。ｎ、、ｎｃは導波路の材料により定まるもの
である。従って、導波路材料と基板の大きさが限定され
た場合、高分解能な回折格子を得るためには円弧の開き
角φを大きく取れば良い。Δλ= 1° = 1°...(3)N
m n cφNΔR In the above equation (3), the product NΔR of the number of waveguides N and the waveguide spacing ΔR approximately indicates the width of the waveguide-shaped diffraction grating, and its size depends on the size of the substrate forming the waveguide. limited to. n, , nc are determined by the material of the waveguide. Therefore, when the waveguide material and the size of the substrate are limited, in order to obtain a high-resolution diffraction grating, it is sufficient to increase the opening angle φ of the circular arc.
「発明が解決しようとする課題」
ところが、現実的には開き角φを３π以上取ることは不
可能であり、これが高分解能化の障害となっている。"Problem to be Solved by the Invention" However, in reality, it is impossible to set the opening angle φ to 3π or more, and this is an obstacle to achieving high resolution.
また、■各三次元導波路の曲率半径が異なるため各三次
元導波路の伝搬特性が一様でない、■入力光軸と出力光
軸のなす角度を任意に設定できないため実際に合分波器
として組み立てる際に光軸合わせなどが煩雑になる、と
いう欠点があった。In addition, ■The propagation characteristics of each three-dimensional waveguide are not uniform because the radius of curvature of each three-dimensional waveguide is different. ■The angle between the input optical axis and the output optical axis cannot be set arbitrarily, so it is difficult to actually use a multiplexer/demultiplexer. The drawback was that alignment of the optical axis was complicated when assembling the device.
本発明は、このような問題を解決課題とし、波長間隔の
狭い波長分割多重伝送システム用光合分波器に適用でき
る高分解能でかつ回折効率の高い導波路形回折格子を提
供することを目的とする。The present invention aims to solve these problems and to provide a waveguide-type diffraction grating with high resolution and high diffraction efficiency that can be applied to an optical multiplexer/demultiplexer for a wavelength division multiplexing transmission system with a narrow wavelength interval. do.
「課題を解決するための手段」
本発明の導波路形回折格子は、入力端を有する第１の二
次元導波路と、出力端を有する第２の二次元導波路と、
第１の二次元導波路と第２の二次元導波路を接続する長
さの異なる複数の三次元導波路からなり、三次元導波路
を伝搬した後の光の位相が各三次元導波路間で異なるこ
とにより波長依存性角度分散を有することを特徴とする
。"Means for Solving the Problems" The waveguide-type diffraction grating of the present invention includes a first two-dimensional waveguide having an input end, a second two-dimensional waveguide having an output end,
Consisting of a plurality of three-dimensional waveguides with different lengths connecting the first two-dimensional waveguide and the second two-dimensional waveguide, the phase of light after propagating through the three-dimensional waveguide is different between each three-dimensional waveguide. It is characterized by having wavelength-dependent angular dispersion.
「作用」
本発明の導波路形回折格子は、長さが異なる複数の三次
元導波路によって、光の位相を各三次元導波路間で異な
らせることにより、形状的に制限されることな（、基板
の大きさが許す範囲内で三次元導波路間に大きな行路長
差を生じさせて、高分解能化を実現する。"Function" The waveguide-type diffraction grating of the present invention uses a plurality of three-dimensional waveguides with different lengths to make the phase of light different between the three-dimensional waveguides, so that the waveguide-type diffraction grating is not limited in shape ( , high resolution is achieved by creating a large path length difference between the three-dimensional waveguides within the range allowed by the size of the substrate.
また、各三次元導波路を円弧状および直線状の三次元導
波路の組合せとすることにより、隣接する三次元導波路
間の行路長差を、直線部分の長さを変えることによって
発生させる。また、この場合には、円弧部の曲率半径を
等しくし、その円弧部の伝搬特性を全ての導波路におい
て等しくして、三次元導波路からの出力を均一にすると
共に、円弧と直線の組合せによって人力光軸と出刃先軸
の角度を任意に設定できるものとする。Furthermore, by forming each three-dimensional waveguide as a combination of arc-shaped and linear three-dimensional waveguides, a path length difference between adjacent three-dimensional waveguides is generated by changing the length of the straight portion. In this case, the radii of curvature of the circular arc parts are made equal, the propagation characteristics of the circular arc parts are made the same in all waveguides, and the output from the three-dimensional waveguide is made uniform, and the combination of circular arcs and straight lines is The angle between the manual optical axis and the cutting edge axis can be set arbitrarily.
また、入力端を含むローランド円の直径を半径とする円
周上に三次元導波路と第１の二次元導波路の結合部を配
置し、出力端を含むローランド円の直径を半径とする円
周上に三次元導波路の他端と第２の二次元導波路の結合
部を配置することにより、コリメート及び集光用のレン
ズを必要としない設計を可能とする。In addition, the coupling part of the three-dimensional waveguide and the first two-dimensional waveguide is arranged on a circle whose radius is the diameter of the Rowland circle including the input end, and the coupling part of the three-dimensional waveguide and the first two-dimensional waveguide is arranged on a circle whose radius is the diameter of the Rowland circle including the output end. By arranging the coupling portion between the other end of the three-dimensional waveguide and the second two-dimensional waveguide on the circumference, a design that does not require collimating and focusing lenses is possible.
さらに、各三次元導波路の途中に高反射率の終端処理を
施すことにより、第１の二次元導波路と第２の二次元導
波路を同一のものとして全体の大きさを半減すると共に
、円弧状の三次元導波路を必要としない構成を実現して
、導波路設計の労力を低減する。Furthermore, by applying high reflectivity termination treatment to the middle of each three-dimensional waveguide, the first two-dimensional waveguide and the second two-dimensional waveguide are made the same, and the overall size is halved. A configuration that does not require an arcuate three-dimensional waveguide is realized to reduce the labor involved in waveguide design.
「実施例」
以下、本発明の詳細な説明するに先立ち、本発明の特徴
と従来技術との差異について説明する。"Example" Before explaining the present invention in detail, the features of the present invention and the differences from the prior art will be explained below.
先述の論文の方法における分解能の限界の原因は、複数
の三次元導波路間の行路長差を円弧の曲率の違いにより
発生させていたことにある。−力木発明においては、長
さの異なる複数の三次元導波路によって、三次元導波路
間に行路長差を生じさせるものであり、そのための−構
成例としては、各三次元導波路を円弧状および直線状の
三次元導波路の組合せとして、隣接する三次元導波路間
の行路長差を、それらの直線部分の長さを変えることに
よって発生させる。この構成例において、円弧状の三次
元導波路の目的は、長さの異なる直線状三次元導波路を
配置するために行路を曲げることであり、行路長差を発
生させることを目的としていないため、曲率半径はすべ
て等しい。この点において本発明と先述の論文の方法は
まった（異なる。The reason for the resolution limit in the method of the above-mentioned paper is that the path length difference between the plurality of three-dimensional waveguides is caused by the difference in the curvature of the circular arc. - In the strength tree invention, a path length difference is created between the three-dimensional waveguides by using a plurality of three-dimensional waveguides having different lengths. As a combination of arcuate and linear three-dimensional waveguides, path length differences between adjacent three-dimensional waveguides are generated by changing the lengths of their straight sections. In this configuration example, the purpose of the arc-shaped three-dimensional waveguide is to bend the path in order to arrange linear three-dimensional waveguides with different lengths, and the purpose is not to create a path length difference. , all have the same radius of curvature. In this respect, the method of the present invention and the method of the above-mentioned paper are different.
ところで、隣接する三次元導波路間の行路長差をΔＬと
すると第２の二次元導波路内の回折光の回折角βは次式
で与えられる。By the way, if the path length difference between adjacent three-dimensional waveguides is ΔL, the diffraction angle β of the diffracted light in the second two-dimensional waveguide is given by the following equation.
ａ （ｇｉｎ ａ ＋ｓｉｎβ）ｎ、＋ΔＬｎａ＝ｍλ
・・・（４）
ここで、ａは第２の二次元導波路に結合する部分におけ
る複数の三次元導波路の間隔、αは入射角である。ｓｉ
ｎα＋ｓｉｎβ＝０なる中心波長λ。においては次式が
成立する。a (gin a + sin β) n, +ΔLna=mλ
(4) Here, a is the interval between the plurality of three-dimensional waveguides in the portion coupled to the second two-dimensional waveguide, and α is the incident angle. si
Center wavelength λ where nα+sinβ=0. The following equation holds true.
ΔＬｎ ｃ
ｍ＝ □ ・・・（５）λ
。ΔLn c m= □ ...(5)λ
.
従って、分解可能最小波長間隔Δλは次式で与えられる
。Therefore, the minimum resolvable wavelength interval Δλ is given by the following equation.
Δλ＝ １・” ・・・（６）ｎｃ
Ｎ ΔＬ
ΔＬには形状的な制限がないため、本発明においては、
基板の大きさが許す範囲内でその値を大きく設定するこ
とが可能となる。従って、容易に高分解能化が可能であ
る。Δλ= 1・” ...(6) nc
Since there is no shape limit on N ΔL ΔL, in the present invention,
It is possible to set the value large within the range allowed by the size of the board. Therefore, high resolution is easily possible.
次に、図面に基づき本発明の実施例について詳述する。Next, embodiments of the present invention will be described in detail based on the drawings.
第１図に本発明の第１の実施例を示す。FIG. 1 shows a first embodiment of the present invention.
本実施例では、導波路基板ｌ上に入力用三次元導波路９
、第１の二次元導波路２、コリメート用導波路レンズ７
、三次元導波路４、第２の二次元導波路３、集光用導波
路レンズ８、出力用三次元導波路ｌＯが配置されている
。各三次元導波路４は４個の９０°円弧状三次元導波路
５と５個の直線状三次元導波路６からなり、その行路長
は隣接するものとΔしたけ異なるように設計する。全て
の円弧状三次元導波路５の曲率半径は等しく、隣接する
導波路間の行路長差ΔＬは直線部の長さの違いにより生
じている。同第１図から明らかなように、本実施例にお
いては、基板の大きさの範囲内であれば、形状的な制限
無しでΔＬを設定できることになる。In this embodiment, an input three-dimensional waveguide 9 is provided on the waveguide substrate l.
, first two-dimensional waveguide 2, collimating waveguide lens 7
, a three-dimensional waveguide 4, a second two-dimensional waveguide 3, a condensing waveguide lens 8, and an output three-dimensional waveguide lO are arranged. Each three-dimensional waveguide 4 is made up of four 90° arc-shaped three-dimensional waveguides 5 and five straight three-dimensional waveguides 6, and is designed so that its path length differs from the adjacent one by an amount of Δ. All the arcuate three-dimensional waveguides 5 have the same radius of curvature, and the path length difference ΔL between adjacent waveguides is caused by the difference in length of the straight portions. As is clear from FIG. 1, in this embodiment, ΔL can be set without any geometrical restrictions as long as it is within the size of the substrate.
このような構成において、入力用三次元導波路９から入
射した波長の異なる光の混合光は、導波路レンズ７によ
り平行光に変換され、第１の二次元導波路２と結合して
いる複数の三次元導波路４に導かれる。三次元導波路４
を伝搬した後の混合光は第２の二次元導波路３内を伝搬
する際、それぞれ前述した（４）式を満足する方向に回
折し、導波路レンズ８により収束され異なる位置に焦点
を結ぶ。出力用三次元導波路１０の一端はあらかじめ各
波長の光が収束する位置に配置されており、異なる波長
の光はそれぞれ異なる三次元導波路８内を伝搬し基板端
に到達する。In such a configuration, mixed light of different wavelengths incident from the input three-dimensional waveguide 9 is converted into parallel light by the waveguide lens 7, and a plurality of parallel lights coupled to the first two-dimensional waveguide 2 are converted into parallel light by the waveguide lens 7. is guided to a three-dimensional waveguide 4. Three-dimensional waveguide 4
When the mixed light propagates through the second two-dimensional waveguide 3, it is diffracted in a direction that satisfies the above-mentioned equation (4), and is converged by the waveguide lens 8 to focus at different positions. . One end of the output three-dimensional waveguide 10 is placed in advance at a position where light of each wavelength converges, and light of different wavelengths propagates in different three-dimensional waveguides 8 and reaches the substrate edge.
本実施例では、各三次元導波路４が５個の直線状三次元
導波路６と４個の円弧状三次元導波路５からなり、入射
光軸と出射光軸が同一直線上にあるとしたが、本発明は
この実施例に限定されるものでなく、例えば、２個の直
線上三次元同一と１個の円弧上三次元導波路を組み合わ
せて、入射光軸と出射光軸を直行させる、等の設計がで
きることは自明である。In this embodiment, each three-dimensional waveguide 4 consists of five linear three-dimensional waveguides 6 and four arc-shaped three-dimensional waveguides 5, and the input optical axis and the output optical axis are on the same straight line. However, the present invention is not limited to this embodiment. For example, by combining two linear three-dimensional waveguides and one circular arc three-dimensional waveguide, the input optical axis and the output optical axis are perpendicular to each other. It is obvious that it is possible to design such that
第２図は本発明の第２の実施例である。FIG. 2 shows a second embodiment of the invention.
本実施例では、第１の二次元導波路１２と結合する三次
元導波路１４の端部が入力用三次元導波路１９端部を含
む第１のローランド円１７の直径を半径とする円周上に
配置され、第２の二次元導波路１３と接合する三次元導
波路１４の端部が出力用三次元導波路２０端部を含むロ
ーランド円１８の直径を半径とする円周上に配置されて
いる。In this embodiment, the end of the three-dimensional waveguide 14 that couples with the first two-dimensional waveguide 12 has a circumference that has a radius equal to the diameter of the first Roland circle 17 that includes the end of the input three-dimensional waveguide 19. The end of the three-dimensional waveguide 14 which is arranged above and joins with the second two-dimensional waveguide 13 is arranged on a circumference whose radius is the diameter of the Rowland circle 18 that includes the end of the output three-dimensional waveguide 20. has been done.
このような配置によりコリメート用レンズと集光用レン
ズが不用となることは従来の凹面回折格子から明らかで
ある。二次元導波路内にレンズを作製する必要がないた
め、１回のバタンニングで作製できプロセスの時間と経
費を大幅に軽減できる。It is clear from conventional concave diffraction gratings that such an arrangement eliminates the need for a collimating lens and a focusing lens. Since there is no need to fabricate a lens within the two-dimensional waveguide, it can be fabricated by one batch of batting, significantly reducing process time and costs.
本実施例における回折格子としての動作及び得られる効
果は第１の実施例と同様である。The operation of the diffraction grating and the effects obtained in this embodiment are the same as in the first embodiment.
第３図は本発明の第３の実施例である。FIG. 3 shows a third embodiment of the invention.
本実施例の特徴は、直線状三次元導波路２３の一端に高
反射率終端処理２４を施すことにより、第１および第２
の実施例で２個必要だった二次元導波路を１（ＩＩとし
ている点である。入力用三次元導波路２６の一端と出力
用三次元導波路２７の一端は同一のローランド円２５上
に配置され、ローランド円２５の直径を半径とする円周
上に三次元導波路２３と二次元導波路２２の結合部が配
置されている。第１および第２の実施例が透過形回折格
子であったのに対して、本実施例は反射形回折格子であ
る。本実施例の構造とすることにより、構造の簡易化と
小型化を図ることができる。また、本実施例では所望の
行路長差ΔＬを円弧状三次元導波路を用いず実現できる
のも特筆すべき点である。本実施例の回折格子としての
動作及び得られる効果は第１および第２の実施例と同様
である。The feature of this embodiment is that by applying high reflectance termination treatment 24 to one end of the linear three-dimensional waveguide 23,
The number of two-dimensional waveguides that were required in the embodiment is one (II). One end of the input three-dimensional waveguide 26 and one end of the output three-dimensional waveguide 27 are on the same Rowland circle 25. The coupling portion of the three-dimensional waveguide 23 and the two-dimensional waveguide 22 is arranged on the circumference of a circle whose radius is the diameter of the Rowland circle 25.The first and second embodiments are transmission type diffraction gratings. In contrast, this embodiment uses a reflection type diffraction grating.By adopting the structure of this embodiment, the structure can be simplified and miniaturized.In addition, in this embodiment, the desired path can be It is also noteworthy that the length difference ΔL can be realized without using an arcuate three-dimensional waveguide.The operation of this example as a diffraction grating and the effects obtained are the same as those of the first and second examples. .
ところで、上述した第１から第３の実施例においては、
二次元導波路と複数の三次元導波路は直接端面結合して
いるためモード変換損失を生じ、回折効率の点からは最
適な構造とは言い難い。この欠点を解決するには、二次
元導波路と複数の三次元導波路の間にテーバ状導波路を
挿入することが有効である。この構造により、本発明の
回折格子としての特徴を損なうことなく回折効率をさら
に向上させることが可能である。By the way, in the first to third embodiments described above,
Since the two-dimensional waveguide and the plurality of three-dimensional waveguides are directly end-coupled, mode conversion loss occurs, and the structure cannot be said to be optimal from the viewpoint of diffraction efficiency. To solve this drawback, it is effective to insert a tapered waveguide between the two-dimensional waveguide and the plurality of three-dimensional waveguides. With this structure, it is possible to further improve the diffraction efficiency without impairing the characteristics of the diffraction grating of the present invention.
また、第１から第３の実施例においては、第１の二次元
導波路レンズと第２の二次元導波路レンズを等しいとし
、第１の二次元導波路に結合する三次元導波路の間隔と
第２の二次元導波路に結合する三次元導波路の間隔とを
等しいとしたが、本発明はこの実施例に限定されるもの
ではなく、異なった値に設計することが可能であること
は明らかである。In addition, in the first to third embodiments, the first two-dimensional waveguide lens and the second two-dimensional waveguide lens are made equal, and the interval between the three-dimensional waveguides coupled to the first two-dimensional waveguide is Although the spacing of the three-dimensional waveguide coupled to the second two-dimensional waveguide is set to be equal, the present invention is not limited to this example, and can be designed to have different values. is clear.
また、第１から第３の実施例においては、三次元導波路
の間隔を一定値とし、三次元導波路の導波路長差を一定
値としたが、本発明はこの実施例に限定されるものでは
なく、間隔と導波路長差が比例の関係にあれば必ずしも
一定の値である必要がないことは明らかである。Further, in the first to third embodiments, the interval between the three-dimensional waveguides was set to a constant value, and the waveguide length difference of the three-dimensional waveguides was set to a constant value, but the present invention is limited to this embodiment. It is clear that the distance does not necessarily have to be a constant value as long as the distance and the waveguide length difference are in a proportional relationship.
また、第１から第３の実施例においては、第１の二次元
導波路に入力用三次元導波路を備え、第２の二次元導波
路に出力用三次元導波路を備えていたが、本発明はこの
実施例に限定されるものではなく、第１の二次元導波路
および第２の二次元導波路の端部から直接入出力が可能
であることは自明である。Further, in the first to third embodiments, the first two-dimensional waveguide was provided with the input three-dimensional waveguide, and the second two-dimensional waveguide was provided with the output three-dimensional waveguide. It is obvious that the present invention is not limited to this embodiment, and direct input/output is possible from the ends of the first two-dimensional waveguide and the second two-dimensional waveguide.
「発明の効果」
以上説明したように、本発明の導波路形回折格子は、長
さが異なる複数の三次元導波路によって、光の位相を各
三次元導波路間で異ならせる構成であるから、形状的に
制限されることなく、基板の大きさが許す範囲内で三次
元導波路間に大きな行路長差を生じさせて、高分解能化
を実現することができる。従って、本発明によればフォ
トリソグラフィ技術を用いて、従来の回折格子よりも高
分解能で、しかも回折効率が高い導波路形回折格子を得
ることができる。また、コリメート用および集光用レン
ズを不用とすることも可能である。これらの特徴は、波
長間隔の小さな波長分割多重伝送システム用導波路形光
合分波器を構成する上で非常に大きな利点となる。"Effects of the Invention" As explained above, the waveguide-type diffraction grating of the present invention is configured to have a plurality of three-dimensional waveguides with different lengths, and the phase of light is made to differ between each three-dimensional waveguide. , high resolution can be achieved by creating a large path length difference between the three-dimensional waveguides within the range allowed by the size of the substrate without being limited in shape. Therefore, according to the present invention, a waveguide diffraction grating with higher resolution and higher diffraction efficiency than conventional diffraction gratings can be obtained using photolithography technology. It is also possible to eliminate the need for collimating and condensing lenses. These features are very advantageous in configuring a waveguide type optical multiplexer/demultiplexer for a wavelength division multiplexing transmission system with a small wavelength spacing.
また、各三次元導波路を円弧状および直線状の三次元導
波路の組合せとすることにより、隣接する三次元導波路
間の行路長差を、直線部分の長さを変えることによって
発生させることができる。Furthermore, by forming each three-dimensional waveguide as a combination of arc-shaped and linear three-dimensional waveguides, it is possible to generate a path length difference between adjacent three-dimensional waveguides by changing the length of the straight part. I can do it.
また、その円弧部の曲率半径を等しくすることにより、
その円弧部の伝搬特性を全ての導波路において等しくし
て、三次元導波路からの出力を均一にすることができる
。また、円弧と直線の組合せにより人力光軸と出力光軸
の角度を任意に設定できる、等先述の論文の方法で問題
となっていた点を解決することができる。しかも、上述
した（５）式で与えられる回折次数の回折光に光の強度
が集中して不用次数への放射が少なく、回折効率が非常
に高い。Also, by making the radius of curvature of the arc part equal,
By making the propagation characteristics of the circular arc portion equal in all waveguides, it is possible to make the output from the three-dimensional waveguide uniform. In addition, the angles between the manual optical axis and the output optical axis can be arbitrarily set by combining circular arcs and straight lines, which solves the problems associated with the method in the above-mentioned paper. Moreover, the intensity of the light is concentrated in the diffracted light of the diffraction order given by the above-mentioned equation (5), so that there is little radiation to unnecessary orders, and the diffraction efficiency is very high.
また、入力端を含むローランド円の直径を半径とする円
周上に三次元導波路と第１の二次元導波路の結合部を配
置し、出力端を含むローランド円の直径を半径とする円
周上に三次元導波路の他端と第２の二次元導波路の結合
部を配置することにより、コリメート及び集光用のレン
ズを必要としない設計が可能となる。In addition, the coupling part of the three-dimensional waveguide and the first two-dimensional waveguide is arranged on a circle whose radius is the diameter of the Rowland circle including the input end, and the coupling part of the three-dimensional waveguide and the first two-dimensional waveguide is arranged on a circle whose radius is the diameter of the Rowland circle including the output end. By arranging the coupling portion between the other end of the three-dimensional waveguide and the second two-dimensional waveguide on the circumference, a design that does not require collimating and focusing lenses is possible.
さらに、各三次元導波路の途中に高反射率の終端処理を
施すことにより、第１の二次元導波路と第２の二次元導
波路を同一のものとすることができる。また、この場合
には、全体の大きさが半減できるだけでな（、円弧状の
三次元導波路を必要としない構成ができて導波路設計の
労力を低減することも可能となる。Furthermore, the first two-dimensional waveguide and the second two-dimensional waveguide can be made the same by performing high-reflectance termination treatment in the middle of each three-dimensional waveguide. Furthermore, in this case, not only can the overall size be halved (but also a configuration that does not require an arcuate three-dimensional waveguide can be created, thereby reducing the labor involved in waveguide design).
第１図は本発明の第１の実施例の構成図、第２図は本発
明の第２の実施例の構成図、第３図は本発明の第３の実
施例の構成図である。
ｌ・・・・・・導波路基板、２・・・・・・第１の二次
元導波路、３・・・・・・第２の二次元導波路、４・・
・・・・三次元導波路、５・・・・・・円弧状三次元導
波路、
６・・・・・・直線状三次元導波路、
７・・・・・・コリメート用導波路レンズ、８・・・・
・・集光用導波路レンズ、
９・・・・・・入力用三次元導波路、
１０・・・・・・出力用三次元導波路、１１・・・・・
・導波路基板、
１２・・・・・・第１の二次元導波路、１３・・・・・
・第２の二次元導波路、１４・・・・・・三次元導波路
、
１５・・・・・・円弧状三次元導波路、１６・・・・・
・直線状三次元導波路、１７・・・・・・第１のローラ
ンド円、８・・・・・・第２のローランド円、
９・・・・・・入力用三次元導波路、
０・・・・・・出力用三次元導波路、
■・・・・・・導波路基板、２２・・・・・・二次元導
波路、３・・・・・・三次元導波路、
４・・・・・・高反射率終端処理、
５・・・・・・ローランド円、
６・・・・・・人力用三次元導波路、
７・・・・・・出力用三次元導波路。
出願人 日本電信電話株式会社
−２にFIG. 1 is a block diagram of a first embodiment of the present invention, FIG. 2 is a block diagram of a second embodiment of the present invention, and FIG. 3 is a block diagram of a third embodiment of the present invention. 1... Waveguide substrate, 2... First two-dimensional waveguide, 3... Second two-dimensional waveguide, 4...
... Three-dimensional waveguide, 5 ... Arc-shaped three-dimensional waveguide, 6 ... Straight three-dimensional waveguide, 7 ... Waveguide lens for collimating, 8...
... Condensing waveguide lens, 9... Three-dimensional waveguide for input, 10... Three-dimensional waveguide for output, 11...
- Waveguide substrate, 12...First two-dimensional waveguide, 13...
・Second two-dimensional waveguide, 14... Three-dimensional waveguide, 15... Arc-shaped three-dimensional waveguide, 16...
- Straight three-dimensional waveguide, 17... First Rowland circle, 8... Second Rowland circle, 9... Three-dimensional waveguide for input, 0. ... three-dimensional waveguide for output, ■ ... waveguide substrate, 22 ... two-dimensional waveguide, 3 ... three-dimensional waveguide, 4 ... ... High reflectance termination treatment, 5 ... Rowland circle, 6 ... Three-dimensional waveguide for human power, 7 ... Three-dimensional waveguide for output. Applicant Nippon Telegraph and Telephone Corporation-2
Claims (4)
有する第２の二次元導波路と、第１の二次元導波路と第
２の二次元導波路を接続する長さの異なる複数の三次元
導波路からなり、三次元導波路を伝搬した後の先の位相
が各三次元導波路間で異なることにより波長依存性角度
分散を有することを特徴とする導波路形回折格子。(1) A first two-dimensional waveguide having an input end, a second two-dimensional waveguide having an output end, and a length connecting the first two-dimensional waveguide and the second two-dimensional waveguide. A waveguide-shaped diffraction grating comprising a plurality of different three-dimensional waveguides and having wavelength-dependent angular dispersion because the phase after propagation through the three-dimensional waveguides is different between the three-dimensional waveguides. .
、曲率半径の等しい複数の円弧状三次元導波路の組合せ
から構成され、各三次元導波路の行路長を直線部分の長
さで調整することにより、任意の位相分布を得ることを
特徴とする第１請求項に記載の導波路形回折格子。(2) Each three-dimensional waveguide is composed of a combination of a plurality of linear three-dimensional waveguides and a plurality of arc-shaped three-dimensional waveguides with the same radius of curvature, and the path length of each three-dimensional waveguide is the straight part of the waveguide. The waveguide diffraction grating according to claim 1, wherein an arbitrary phase distribution can be obtained by adjusting the length.
端は、入力端を含む第１のローランド円の直径を半径と
する円周上に配置され、第２の二次元導波路と結合する
三次元導波路の他端は、出力端を含む第２のローランド
円の直径を半径とする円周上に配置されていることを特
徴とする第１請求項に記載の導波路形回折格子。(3) One end of the three-dimensional waveguide coupled to the first two-dimensional waveguide is arranged on a circumference whose radius is the diameter of the first Rowland circle including the input end, and the second two-dimensional waveguide is connected to the second two-dimensional waveguide. The waveguide shape according to claim 1, characterized in that the other end of the three-dimensional waveguide coupled to is arranged on a circumference having a radius equal to the diameter of the second Rowland circle including the output end. Diffraction grating.
であって、入力端、出力端及び複数の三次元導波路の片
端と結合し、三次元導波路の他端は高反射率終端とされ
ていることを特徴とする第１請求項に記載の導波路形回
折格子。(4) The first two-dimensional waveguide and the second two-dimensional waveguide are the same and are coupled to the input end, the output end, and one end of the plurality of three-dimensional waveguides, and the other end of the three-dimensional waveguide is The waveguide-type diffraction grating according to claim 1, characterized in that it is terminated with a high reflectance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6558889A JP2599786B2 (en) | 1989-03-17 | 1989-03-17 | Waveguide type diffraction grating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6558889A JP2599786B2 (en) | 1989-03-17 | 1989-03-17 | Waveguide type diffraction grating |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02244105A true JPH02244105A (en) | 1990-09-28 |
| JP2599786B2 JP2599786B2 (en) | 1997-04-16 |
Family
ID=13291323
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6558889A Expired - Lifetime JP2599786B2 (en) | 1989-03-17 | 1989-03-17 | Waveguide type diffraction grating |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2599786B2 (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06250133A (en) * | 1993-02-19 | 1994-09-09 | American Teleph & Telegr Co <Att> | Optical filter device |
| JPH0763934A (en) * | 1993-08-30 | 1995-03-10 | Nippon Telegr & Teleph Corp <Ntt> | Optical waveguide circuit |
| WO2000034811A1 (en) * | 1998-12-09 | 2000-06-15 | The Furukawa Electric Co., Ltd. | Arrayed waveguide grating multiplexer and demultiplexer |
| US6842560B2 (en) | 2001-02-27 | 2005-01-11 | Ntt Electronics Corporation | Optical multiplexing circuit and optical multiplexer |
| WO2005081022A1 (en) * | 2004-02-19 | 2005-09-01 | Keio University | Array waveguide diffraction grating |
| US6996302B2 (en) | 2002-11-29 | 2006-02-07 | Matsushita Electric Industrial Co., Ltd | Optical demultiplexer, optical multi-/demultiplexer, and optical device |
| US7164817B2 (en) | 2002-05-24 | 2007-01-16 | Hoya Corporation | Optical switch and optical add/drop multiplexer using the same |
| US7236657B2 (en) | 2002-05-24 | 2007-06-26 | Hoya Corporation | Optical switch and optical add/drop multiplexer using the same |
| JP2009251176A (en) * | 2008-04-03 | 2009-10-29 | Nippon Telegr & Teleph Corp <Ntt> | Optical signal processing circuit |
| JP2012203173A (en) * | 2011-03-25 | 2012-10-22 | Fujitsu Ltd | Optical waveguide element and optical hybrid circuit |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003050327A (en) | 2001-05-31 | 2003-02-21 | Hoya Corp | Optical waveguide device and method for manufacturing the same |
-
1989
- 1989-03-17 JP JP6558889A patent/JP2599786B2/en not_active Expired - Lifetime
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06250133A (en) * | 1993-02-19 | 1994-09-09 | American Teleph & Telegr Co <Att> | Optical filter device |
| JPH0763934A (en) * | 1993-08-30 | 1995-03-10 | Nippon Telegr & Teleph Corp <Ntt> | Optical waveguide circuit |
| WO2000034811A1 (en) * | 1998-12-09 | 2000-06-15 | The Furukawa Electric Co., Ltd. | Arrayed waveguide grating multiplexer and demultiplexer |
| US6404946B1 (en) | 1998-12-09 | 2002-06-11 | The Furukawa Electric Co., Ltd. | Arrayed waveguide grating type optical multiplexer/demultiplexer |
| US6842560B2 (en) | 2001-02-27 | 2005-01-11 | Ntt Electronics Corporation | Optical multiplexing circuit and optical multiplexer |
| US7164817B2 (en) | 2002-05-24 | 2007-01-16 | Hoya Corporation | Optical switch and optical add/drop multiplexer using the same |
| US7236657B2 (en) | 2002-05-24 | 2007-06-26 | Hoya Corporation | Optical switch and optical add/drop multiplexer using the same |
| US6996302B2 (en) | 2002-11-29 | 2006-02-07 | Matsushita Electric Industrial Co., Ltd | Optical demultiplexer, optical multi-/demultiplexer, and optical device |
| WO2005081022A1 (en) * | 2004-02-19 | 2005-09-01 | Keio University | Array waveguide diffraction grating |
| JP2009251176A (en) * | 2008-04-03 | 2009-10-29 | Nippon Telegr & Teleph Corp <Ntt> | Optical signal processing circuit |
| JP2012203173A (en) * | 2011-03-25 | 2012-10-22 | Fujitsu Ltd | Optical waveguide element and optical hybrid circuit |
| US8837879B2 (en) | 2011-03-25 | 2014-09-16 | Fujitsu Limited | Optical waveguide device and optical hybrid circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2599786B2 (en) | 1997-04-16 |
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