JP3147564B2 - Optical circuit - Google Patents
Optical circuitInfo
- Publication number
- JP3147564B2 JP3147564B2 JP1552393A JP1552393A JP3147564B2 JP 3147564 B2 JP3147564 B2 JP 3147564B2 JP 1552393 A JP1552393 A JP 1552393A JP 1552393 A JP1552393 A JP 1552393A JP 3147564 B2 JP3147564 B2 JP 3147564B2
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- Japan
- Prior art keywords
- optical
- optical waveguide
- core
- face
- glass
- Prior art date
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、ガラス光導波路とアレ
イ状の光半導体素子とを一体化したハイブリッド型光集
積回路を実現する光回路に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical circuit for realizing a hybrid optical integrated circuit in which a glass optical waveguide and an array of optical semiconductor elements are integrated.
【０００２】[0002]
【従来の技術】図２は従来のこの種の光回路の一例を示
すもので、同図(a) は平面図、同図(b) は側面図であ
る。図中、１はガラス光導波路、２はガラス光導波路１
の略並列に配置された複数のコア、３はガラス光導波路
１の端面、４はアレイ状の光半導体素子、５は光半導体
素子４の略並列に配置された複数のコア、６はＳｉ基
板、７は光半導体素子４のハンダ固定部、８は光信号の
経路である。2. Description of the Related Art FIG. 2 shows an example of a conventional optical circuit of this type. FIG. 2A is a plan view and FIG. 2B is a side view. In the figure, 1 is a glass optical waveguide, 2 is a glass optical waveguide 1
A plurality of cores arranged substantially in parallel with each other, 3 an end face of the glass optical waveguide 1, 4 an array of optical semiconductor elements, 5 a plurality of cores arranged substantially in parallel with the optical semiconductor elements 4, 6 a Si substrate , 7 are solder fixing portions of the optical semiconductor element 4, and 8 is a path of an optical signal.
【０００３】前記ガラス光導波路１はＳｉ基板６上に直
接形成され、その端面３はドライエッチング等の技術に
より、複数のコア２の光軸及びＳｉ基板６に対して垂直
に形成されている。また、光半導体素子４はその複数の
コア５の光軸と前記ガラス光導波路１の複数のコア２の
光軸とがそれぞれ一致する如く、ハンダ固定部７を介し
てＳｉ基板６に取り付けられている。而して、ガラス光
導波路１のコア２と光半導体素子４のコア５とは空間的
な経路８を介して光学的に結合され、光信号がやりとり
されることになる。The glass optical waveguide 1 is formed directly on a Si substrate 6, and its end face 3 is formed perpendicular to the optical axes of the cores 2 and the Si substrate 6 by a technique such as dry etching. The optical semiconductor element 4 is attached to the Si substrate 6 via the solder fixing part 7 so that the optical axes of the plurality of cores 5 and the optical axes of the plurality of cores 2 of the glass optical waveguide 1 respectively match. I have. Thus, the core 2 of the glass optical waveguide 1 and the core 5 of the optical semiconductor element 4 are optically coupled via the spatial path 8, and optical signals are exchanged.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、前述し
た光回路では、ガラス光導波路１の端面３がコア２の光
軸に対して垂直であるため、ガラス光導波路１から光半
導体素子４へ伝搬される光信号のうちで該端面３により
反射されてガラス光導波路１に戻る光信号、並びに光半
導体素子４からガラス光導波路１へ伝搬される光信号の
うちで該端面３により反射されて光半導体素子４に戻る
光信号（反射戻り光：反射光のうちで信号光路に再結合
する成分）が多く発生し、光半導体素子４や本光回路に
接続される外部の回路の動作を不安定にするという問題
があった。However, in the above-described optical circuit, since the end face 3 of the glass optical waveguide 1 is perpendicular to the optical axis of the core 2, the light propagates from the glass optical waveguide 1 to the optical semiconductor element 4. Optical signal reflected by the end face 3 and returning to the glass optical waveguide 1 among optical signals, and an optical semiconductor reflected by the end face 3 and reflected in the optical signal transmitted from the optical semiconductor element 4 to the glass optical waveguide 1 Many optical signals returning to the element 4 (reflected return light: a component of the reflected light that recombines with the signal light path) are generated, and the operation of the optical semiconductor element 4 or an external circuit connected to the optical circuit is unstable. There was a problem of doing.
【０００５】前記問題を解決する手段としては、1)ガラ
ス光導波路１の端面３に誘電体等による無反射コートを
施す、2)ガラス光導波路１の端面３をコア２の光軸に対
して少し傾け、反射光がコア２又は５へ戻らないように
する、といったことが考えられる。As means for solving the above problems, 1) an anti-reflection coating made of a dielectric or the like is applied to the end face 3 of the glass optical waveguide 1; 2) the end face 3 of the glass optical waveguide 1 is It is conceivable to incline it slightly to prevent reflected light from returning to the core 2 or 5.
【０００６】しかしながら、無反射コートを施しても３
５ｄＢ以上の反射減衰量（入射光に対する反射光の減衰
率）を得ることは困難である上、端面が基板中央部にあ
る場合には無反射コートを施すこと自体が困難であると
いう問題があった。また、端面を傾けた場合、光信号の
経路が曲ることになり、光半導体素子もガラス光導波路
に対して傾けねばならないため、両者の間隙が大きく開
いて結合効率が悪くなり、特にアレイ状の光半導体素子
の場合には顕著になるという問題があった。However, even if an anti-reflection coating is applied, 3
It is difficult to obtain a return loss of 5 dB or more (attenuation rate of reflected light with respect to incident light), and furthermore, it is difficult to apply an anti-reflection coating when the end face is located at the center of the substrate. Was. If the end face is tilted, the path of the optical signal will bend, and the optical semiconductor element must also be tilted with respect to the glass optical waveguide. In the case of the optical semiconductor device described above, there is a problem that it becomes remarkable.
【０００７】本発明は前記従来の問題点に鑑み、ガラス
光導波路及び光半導体素子間の結合効率を悪化させるこ
となく、ガラス光導波路の端面における反射戻り光を減
少させ得る光回路を提供することを目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and provides an optical circuit capable of reducing the reflected return light at the end face of the glass optical waveguide without deteriorating the coupling efficiency between the glass optical waveguide and the optical semiconductor element. With the goal.
【０００８】[0008]
【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、略並列に配置された複数のコアを有するガ
ラス光導波路と、略並列に配置され且つ前記ガラス光導
波路の複数のコアにそれぞれ光学的に結合される複数の
コアを有するアレイ状の光半導体素子とからなる光回路
において、ガラス光導波路とアレイ状の光半導体素子と
は同一の基板上に配置され、ガラス光導波路の端面を、
基板に対して垂直で、各コアの近傍部が該各コアの光軸
に直交する方向に対して傾き且つガラス光導波路のコア
とこれに対応する光半導体素子のコアとの間隙が各コア
毎に等しくなるよう形成した光回路を提案する。According to the present invention, in order to achieve the above object, a glass optical waveguide having a plurality of cores arranged substantially in parallel and a plurality of cores of the glass optical waveguide arranged substantially in parallel are provided. An optical circuit comprising an array of optical semiconductor elements each having a plurality of optically coupled cores, wherein a glass optical waveguide and an array of optical semiconductor elements are provided.
Are arranged on the same substrate, and the end face of the glass optical waveguide is
Perpendicularly to the substrate, the vicinity of each core is inclined with respect to the direction orthogonal to the optical axis of each core, and the gap between the core of the glass optical waveguide and the core of the corresponding optical semiconductor element is different for each core. An optical circuit formed to be equal to is proposed.
【０００９】[0009]
【作用】本発明によれば、ガラス光導波路から光半導体
素子へ伝搬される光信号のうちでガラス光導波路の端面
により反射される光信号は、該端面がコアの光軸に直交
する方向に対して傾いているため、ガラス光導波路のコ
アに再結合しない。また、光半導体素子からガラス光導
波路へ伝搬される光信号のうちでガラス光導波路の端面
により反射される光信号は、該端面がコアの光軸に直交
する方向に対して傾いているため、光半導体素子のコア
に再結合しない。従って、ガラス光導波路の端面による
反射戻り光は大幅に減少する。また、ガラス光導波路の
コアとこれに対応する光半導体素子のコアとの間隙が各
コア毎に等しいので、ガラス光導波路及びアレイ状の光
半導体素子間の結合効率は悪化しない。According to the present invention, of the optical signals propagated from the glass optical waveguide to the optical semiconductor device, the optical signals reflected by the end face of the glass optical waveguide are arranged such that the end face is perpendicular to the optical axis of the core. Since it is inclined with respect to the glass optical waveguide, it does not recombine with the core of the glass optical waveguide. Further, among the optical signals propagated from the optical semiconductor element to the glass optical waveguide, the optical signal reflected by the end face of the glass optical waveguide is inclined with respect to the direction in which the end face is orthogonal to the optical axis of the core. Does not recombine with the core of the optical semiconductor device. Therefore, the reflected light returned by the end face of the glass optical waveguide is greatly reduced. Further, since the gap between the core of the glass optical waveguide and the core of the corresponding optical semiconductor element is equal for each core, the coupling efficiency between the glass optical waveguide and the array of optical semiconductor elements does not deteriorate.
【００１０】[0010]
【実施例】図１は本発明の光回路の第１の実施例を示す
もので、図中、図２と同一構成部分は同一符号をもって
表す。即ち、４はアレイ状の光半導体素子、５は光半導
体素子４の略並列に配置された複数のコア、１１はガラ
ス光導波路、１２はガラス光導波路１１の略並列に配置
された複数のコア、１３はガラス光導波路１１の端面、
１４は光信号の経路である。なお、素子の高さ方向の関
係は図２の場合と同様であるから、側面図は省略した。FIG. 1 shows a first embodiment of the optical circuit of the present invention. In FIG. 1, the same components as those in FIG. 2 are denoted by the same reference numerals. That is, 4 is an array of optical semiconductor elements, 5 is a plurality of cores arranged substantially in parallel with the optical semiconductor element 4, 11 is a glass optical waveguide, and 12 is a plurality of cores arranged in a substantially parallel manner of the glass optical waveguide 11. , 13 are end faces of the glass optical waveguide 11,
Reference numeral 14 denotes an optical signal path. Note that the relationship in the height direction of the element is the same as that in FIG. 2, so that the side view is omitted.
【００１１】ガラス光導波路１１は石英ガラス系で製造
されており、その端面１３は図示しない基板に対して垂
直で各コア１２の近傍部が該各コアの光軸に直交する方
向に対して８°傾き、且つ、該ガラス光導波路１１のコ
ア１２とこれに対応する光半導体素子４のコア５との間
隙が各コア毎に等しくなるよう、階段状に形成されてい
る。このような複雑な端面を製造するには、フォトリソ
グラフィープロセスを使用してマスクを作り、ドライエ
ッチング技術で加工すれば良い。なお、両方の端面１３
相互の位置精度や角度精度もマスク合せなので非常に高
い精度が得られる。The glass optical waveguide 11 is made of silica glass, and its end face 13 is perpendicular to the substrate (not shown) and the vicinity of each core 12 is 8 mm in the direction perpendicular to the optical axis of each core. The glass optical waveguide 11 is formed in a stepwise manner so as to be inclined and the gap between the core 12 of the glass optical waveguide 11 and the core 5 of the corresponding optical semiconductor element 4 becomes equal for each core. In order to manufacture such a complicated end face, a mask may be formed using a photolithography process and processed by a dry etching technique. Note that both end faces 13
Very high accuracy can be obtained because the mutual position accuracy and angle accuracy are also mask matching.
【００１２】前記構成において、ガラス光導波路１１か
ら光半導体素子４へ伝搬される光信号のうちで端面１３
より出射される光信号は、該端面１３がコア１２の光軸
に直交する方向に対して傾いているため、その方向が周
知の「スネルの法則」に基づいて曲げられる。In the above structure, the end face 13 of the optical signal propagated from the glass optical waveguide 11 to the optical semiconductor element 4 is formed.
Since the end face 13 is inclined with respect to the direction orthogonal to the optical axis of the core 12, the direction of the emitted light signal is bent based on the well-known "Snell's law".
【００１３】即ち、図３に示すように、光信号が屈折率
ｎ1 の媒質から屈折率ｎ2 の媒質へ入射する場合、その
入射角φ1 と出射角φ2 （単位はラジアン）との間に
は、偏波の影響を無視すると、 sinφ2 ／ sinφ1 ＝ｎ1 ／ｎ2 ……(1) の関係が成り立つ。本実施例ではφ1 ＝８°、ｎ1 ＝1.
45（石英ガラス）、ｎ2＝１（空気）であるから、前記
(1) 式より、φ2 ≒１２°となり、光信号の振れ角（≡
φ2 −φ1 ）は４°となる。That is, as shown in FIG. 3, when an optical signal enters a medium having a refractive index of n 2 from a medium having a refractive index of n 1 , the angle of incidence φ 1 and the angle of emission φ 2 (in radians) are different. between, ignoring the effects of polarization, sinφ 2 / sinφ 1 = n 1 / n 2 ...... relationship holds in (1). In the present embodiment, φ 1 = 8 ° and n 1 = 1.
45 (quartz glass) and n 2 = 1 (air),
From equation (1), φ 2 ≒ 12 °, and the deflection angle (≡
φ2-φ1) is 4 °.
【００１４】従って、予め光半導体素子４を、そのコア
５がガラス光導波路１１のコア１２に対して４°傾き且
つ該コア５の端面位置がコア１２からの光信号の入射位
置と一致するように設けておくことにより、ガラス光導
波路１１のコア１２より出射される光信号は光半導体素
子４のコア５へ結合されて入射される。また、光半導体
素子４からガラス光導波路１１へ伝搬される光信号のう
ちで端面１３に入射される光信号も、該端面１３がコア
５の光軸に直交する方向に対して傾いており、その方向
が前記同様に曲げられるため、ガラス光導波路１１のコ
ア１２へ結合されて入射される。Therefore, the optical semiconductor element 4 is preliminarily tilted so that its core 5 is inclined by 4 ° with respect to the core 12 of the glass optical waveguide 11 and the end face position of the core 5 coincides with the incident position of the optical signal from the core 12. The optical signal emitted from the core 12 of the glass optical waveguide 11 is coupled to the core 5 of the optical semiconductor element 4 and is incident. Further, among the optical signals transmitted from the optical semiconductor element 4 to the glass optical waveguide 11, the optical signal incident on the end face 13 is also inclined with respect to the direction perpendicular to the optical axis of the core 5, Since the direction is bent as described above, the light is coupled to the core 12 of the glass optical waveguide 11 and is incident.
【００１５】一方、ガラス光導波路１１から光半導体素
子４へ伝搬される光信号のうちで端面１３により反射さ
れる光信号は、該端面１３がコア１２の光軸に直交する
方向に対して傾いているため、コア１２に再結合しな
い。また、同様に、光半導体素子４からガラス光導波路
１１へ伝搬される光信号のうちで端面１３により反射さ
れる光信号は、該端面１３がコア５の光軸に直交する方
向に対して傾いているため、コア５に再結合しない。従
って、ガラス光導波路１１の端面１３による反射戻り光
は大幅に減少する。On the other hand, of the optical signals propagated from the glass optical waveguide 11 to the optical semiconductor element 4, the optical signal reflected by the end face 13 is inclined with respect to the direction in which the end face 13 is orthogonal to the optical axis of the core 12. Therefore, it does not rejoin the core 12. Similarly, among the optical signals propagated from the optical semiconductor element 4 to the glass optical waveguide 11, the optical signal reflected by the end face 13 is inclined with respect to the direction in which the end face 13 is orthogonal to the optical axis of the core 5. Therefore, it does not recombine with the core 5. Therefore, the return light reflected by the end face 13 of the glass optical waveguide 11 is greatly reduced.
【００１６】前述したコアの光軸に直交する方向に対す
る端面の傾き（以下、端面の角度と称す。）と反射戻り
光との関係は、単一モード導波路の場合、ガウシアンビ
ーム近似により簡単に評価できる。The relationship between the inclination of the end face with respect to the direction perpendicular to the optical axis of the core (hereinafter referred to as the angle of the end face) and the reflected return light can be easily calculated by Gaussian beam approximation in the case of a single mode waveguide. Can be evaluated.
【００１７】図４(a) 及び(b) は端面の角度を変化させ
た場合の透過率及び反射減衰量を計算したものである。
本計算は、石英ガラス（ｎ＝1.45）からなるガラス光導
波路より空気（ｎ＝１）中に光信号を出射する場合を想
定しており、光信号の波長（λ）は1.3 μｍ、ガラス光
導波路のスポットサイズ（ω）は５μｍ，３μｍの２つ
のケースについて計算した。なお、透過率については平
面波近似で計算したのでスポットサイズに依存しない。FIGS. 4A and 4B show the calculated transmittance and return loss when the angle of the end face is changed.
In this calculation, it is assumed that an optical signal is emitted from a glass optical waveguide made of quartz glass (n = 1.45) into air (n = 1). The wavelength (λ) of the optical signal is 1.3 μm, and the glass optical waveguide is used. The spot size (ω) of the wave path was calculated for two cases of 5 μm and 3 μm. The transmittance does not depend on the spot size because it is calculated by plane wave approximation.
【００１８】図４(a) では端面の角度に対する偏波方向
（ＴＭ／ＴＥモード）別の透過率（％）を示しており、
端面の角度が増すと光の偏波方向によって反射率に差が
出てくることがわかる。一般に、光信号の偏波は規定さ
れていないので、光部品が偏波依存性を持つことは好ま
しくない。従って、端面の角度を極端に大きくすること
はできない。FIG. 4A shows the transmittance (%) for each polarization direction (TM / TE mode) with respect to the angle of the end face.
It can be seen that as the angle of the end face increases, the reflectivity differs depending on the polarization direction of the light. Generally, since the polarization of an optical signal is not specified, it is not preferable that the optical component has polarization dependency. Therefore, the angle of the end face cannot be extremely increased.
【００１９】また、図４(b) ではガウシアンビーム近似
によって求めた反射減衰量（ｄＢ）を示している。反射
減衰量はスポットサイズに反比例するので、同じ端面の
角度に対してはω＝３μｍのケースの方が反射減衰量は
小さくなる。このグラフより４０ｄＢ以上の反射減衰量
を得ようとすれば、端面の角度はω＝５μｍで６°以
上、ω＝３μｍで１０°以上が必要であることがわか
る。FIG. 4 (b) shows the return loss (dB) obtained by Gaussian beam approximation. Since the return loss is inversely proportional to the spot size, the return loss is smaller in the case of ω = 3 μm for the same end face angle. From this graph, it can be seen that in order to obtain a return loss of 40 dB or more, the angle of the end face needs to be 6 ° or more at ω = 5 μm and 10 ° or more at ω = 3 μm.
【００２０】本実施例において、光信号の波長を1.31μ
ｍ、ガラス光導波路のスポットサイズを一般的な単一モ
ードファイバと同一の５μｍとした場合、端面の角度を
４°とすれば反射減衰量は２６ｄＢとなり、また、６°
とすれば４１ｄＢとなり、さらにまた、８°とすれば６
３ｄＢとなる。実際に、端面の角度を８°として測定し
たところ、測定限界である４０ｄＢ以上の高い反射減衰
量が得られた。なお、スポットサイズが大きめのガラス
光導波路を用い、反射減衰量が３０ｄＢ程度で良いシス
テムであれば、端面の角度は４°ぐらいでも使用できる
可能性がある。In this embodiment, the wavelength of the optical signal is set to 1.31 μm.
m, when the spot size of the glass optical waveguide is 5 μm, which is the same as that of a general single mode fiber, if the angle of the end face is 4 °, the return loss is 26 dB and 6 °.
Is 41 dB, and 8 ° is 6 dB.
3 dB. Actually, when the angle of the end face was measured at 8 °, a high return loss of 40 dB or more, which is a measurement limit, was obtained. If a glass optical waveguide having a large spot size is used and the return loss can be as low as about 30 dB, there is a possibility that the end face can be used at an angle of about 4 °.
【００２１】また、本光回路ではガラス光導波路１１の
端面１３のコア１２の近傍部が他の部分に比べて奥に引
っ込むので、光半導体素子４をガラス光導波路１１に対
して光軸合せする際、光半導体素子４のコア５をガラス
光導波路１１の端面１３にぶつけて破損する危険性が少
ないという利点もある。Further, in the present optical circuit, the portion near the core 12 on the end face 13 of the glass optical waveguide 11 is retracted deeper than other portions, so that the optical semiconductor element 4 is optically aligned with the glass optical waveguide 11. In this case, there is also an advantage that there is less danger of the core 5 of the optical semiconductor element 4 being hit against the end face 13 of the glass optical waveguide 11 and being damaged.
【００２２】図５は本発明の第２の実施例を示すもの
で、ここではガラス光導波路の端面に光半導体素子の端
面と平行な部分を設けている。即ち、図中、２１はガラ
ス光導波路、２２はガラス光導波路２１の略並列に配置
された複数のコア、２３はガラス光導波路２１の端面、
２３´は端面２３の光半導体素子の端面と平行な部分、
２４は光信号の経路である。前記部分２３´に光半導体
素子４の端面（コアのない部分）を突き当てることによ
って、ガラス光導波路２１と光半導体素子４との光軸合
せを無調整化することが可能である。FIG. 5 shows a second embodiment of the present invention. Here, a portion parallel to the end surface of the optical semiconductor element is provided on the end surface of the glass optical waveguide. That is, in the figure, 21 is a glass optical waveguide, 22 is a plurality of cores arranged substantially in parallel with the glass optical waveguide 21, 23 is an end face of the glass optical waveguide 21,
23 'is a portion of the end face 23 parallel to the end face of the optical semiconductor element;
24 is an optical signal path. By abutting the end surface (portion without a core) of the optical semiconductor element 4 on the portion 23 ′, it is possible to adjust the optical axis of the glass optical waveguide 21 and the optical semiconductor element 4 without adjustment.
【００２３】この場合、予め端面２３におけるコア２２
の位置から部分２３´の延長線上の位置までが所定の距
離になるようにマスク設計しておく必要があるが、これ
は簡単な幾何光学的計算により可能である。また、この
際、２つのガラス光導波路２１の間隔を光半導体素子４
の両端面間の長さに一致させると組立作業が困難になる
ので、少し長めに作っておき、どちらか片面を合せれば
他端の間隙も合うように設定しておけば良い。なお、そ
の他の構成・作用は第１の実施例と同様である。In this case, the core 22 on the end face 23 is previously determined.
It is necessary to design a mask so that a predetermined distance is provided from the position to the position on the extension of the portion 23 ', but this can be achieved by a simple geometrical optical calculation. At this time, the interval between the two glass optical waveguides 21 is set to be equal to that of the optical semiconductor element 4.
Since the assembly work becomes difficult if the length between both end surfaces is made equal, the length may be made slightly longer and the gap at the other end may be set to match if one of the surfaces is joined. Other configurations and operations are the same as those of the first embodiment.
【００２４】図６は本発明の第３の実施例を示すもの
で、ここでは第２の実施例においてガラス光導波路のコ
アの先端に球レンズを設けている。即ち、図中、２５は
ガラス光導波路２１のコア２２を半球形状に突出させ、
レンズ効果を持たせた球レンズである。該球レンズ２５
により、ガラス光導波路２１からの光信号のスポットを
絞り込み、光半導体素子４のスポットとマッチングさせ
て結合効率を改善させることができる。FIG. 6 shows a third embodiment of the present invention. In this embodiment, a spherical lens is provided at the tip of the core of the glass optical waveguide in the second embodiment. That is, in the figure, reference numeral 25 indicates that the core 22 of the glass optical waveguide 21 projects in a hemispherical shape,
A spherical lens with a lens effect. The ball lens 25
Thereby, the spot of the optical signal from the glass optical waveguide 21 can be narrowed down and matched with the spot of the optical semiconductor element 4 to improve the coupling efficiency.
【００２５】前述した球レンズは選択エッチング法によ
り作製できる。例えば、ガラス光導波路２１が石英ガラ
ス系でコア２２のドーパントがゲルマニウムの場合に
は、緩衝フッ酸液で端面２３をエッチングすればコア２
２のみが突出した形状を得ることができる。The above-mentioned spherical lens can be manufactured by a selective etching method. For example, when the glass optical waveguide 21 is a quartz glass-based material and the dopant of the core 22 is germanium, the end face 23 is etched with a buffered hydrofluoric acid solution.
Only 2 can obtain a protruding shape.
【００２６】このような結合系の場合、最大結合効率は
上がるものの、球レンズ２５と光半導体素子４との間隙
のトレランスが厳しくなるという問題があるが、本発明
を用いれば、第２の実施例で説明したように予めマスク
設計により間隙の無調整化が可能なので、光軸合せが非
常に楽になる。なお、半球状の球レンズの代りに小径の
真球状の球レンズを用いても本実施例と同様の効果が期
待できる。また、その他の構成・作用は第２の実施例と
同様である。In the case of such a coupling system, although the maximum coupling efficiency is increased, there is a problem that the tolerance of the gap between the spherical lens 25 and the optical semiconductor element 4 becomes strict. As described in the example, since the gap can be made unadjustable by designing the mask in advance, the optical axis alignment becomes very easy. It should be noted that the same effect as in the present embodiment can be expected even if a small-diameter true spherical ball lens is used instead of the hemispherical spherical lens. Other configurations and operations are the same as those of the second embodiment.
【００２７】図７は本発明の第４の実施例を示すもの
で、ここでは従来の端面が直線状のガラス光導波路に後
から追加加工して光半導体素子を挿入するようになした
例を示す。即ち、図中、３１はガラス光導波路、３２は
ガラス光導波路３１の略並列に配置された複数のコア、
３３は直線状の端面に追加加工して形成したガラス光導
波路３１の端面、３４は球レンズ、３５は光信号の経路
である。FIG. 7 shows a fourth embodiment of the present invention. In this embodiment, an optical semiconductor element is inserted into a conventional glass optical waveguide having a straight end face by additional processing. Show. That is, in the figure, 31 is a glass optical waveguide, 32 is a plurality of cores arranged substantially in parallel with the glass optical waveguide 31,
Reference numeral 33 denotes an end surface of the glass optical waveguide 31 formed by additionally processing a linear end surface, reference numeral 34 denotes a spherical lens, and reference numeral 35 denotes an optical signal path.
【００２８】本実施例では光半導体素子４のコア５に対
して光信号が斜めに結合することによる結合損失増が生
ずるが、角度による損失増はスポットサイズに反比例す
るため、スポットサイズの小さい光半導体素子側では影
響は少ない。即ち、ガウシアンビーム近似の計算によれ
ば、スポットサイズ 1.5μｍ、信号波長1.31μｍ、入射
角４°（ガラス光導波路の端面の角度が約８°のケース
に相当）の場合の損失増は約0.27ｄＢであり、通常のレ
ーザダイオードと光ファイバとの間の結合損失が３ｄＢ
程度あることを考えれば十分小さいといえる。なお、そ
の他の構成・作用は第１、第３の実施例と同様である。In this embodiment, the coupling loss increases due to the diagonal coupling of the optical signal to the core 5 of the optical semiconductor element 4. However, the loss increase due to the angle is inversely proportional to the spot size. The effect is small on the semiconductor element side. That is, according to the Gaussian beam approximation calculation, the increase in loss in the case of a spot size of 1.5 μm, a signal wavelength of 1.31 μm, and an incident angle of 4 ° (corresponding to the case where the angle of the end face of the glass optical waveguide is about 8 °) is about 0.27. and the coupling loss between the ordinary laser diode and the optical fiber is 3 dB.
Considering that there are some degrees, it can be said that it is small enough. Other configurations and operations are the same as those of the first and third embodiments.
【００２９】図８は本発明の第５の実施例を示すもの
で、ここでは光半導体素子側もその端面をコアに対して
傾けることにより、反射戻り光をより少なくした例を示
す。即ち、図中、４１はガラス光導波路、４２はガラス
光導波路４１の略並列に配置された複数のコア、４３は
ガラス光導波路４１の端面、４４はアレイ状の光半導体
素子、４５は光半導体素子４４の略並列に配置された複
数のコア、４６は光半導体素子４４の端面、４７は光信
号の経路である。この場合、光半導体素子４４の方が屈
折率が高く、その端面４６での光信号の振れ角が大きく
（約６°）なるので、図示したような光路配置となる
が、予め計算してマスク設計しておけば問題なく作製可
能である。なお、その他の構成・作用は第１の実施例と
同様である。FIG. 8 shows a fifth embodiment of the present invention. In this embodiment, the optical semiconductor element side has its end face inclined with respect to the core so that the reflected return light is further reduced. That is, in the figure, 41 is a glass optical waveguide, 42 is a plurality of cores arranged substantially in parallel with the glass optical waveguide 41, 43 is an end face of the glass optical waveguide 41, 44 is an optical semiconductor element in an array, and 45 is an optical semiconductor. A plurality of cores arranged substantially in parallel with the element 44, 46 is an end face of the optical semiconductor element 44, and 47 is a path of an optical signal. In this case, the optical semiconductor element 44 has a higher refractive index, and the deflection angle of the optical signal at its end face 46 is larger (about 6 °). If they are designed, they can be manufactured without any problems. Other configurations and operations are the same as those of the first embodiment.
【００３０】図９は本発明の第６の実施例を示すもの
で、ここではガラス光導波路のコアを傾けることによ
り、光半導体素子に対して左右対称としたものである。
即ち、図中、５１はガラス光導波路、５２はガラス光導
波路５１の略並列に配置された複数のコア、５３はガラ
ス光導波路５１の端面、５４は球レンズ、５５は光信号
の経路である。本実施例では端面５３を加工する際にオ
ーバーエッチングが生じても両端面とも等しくずれて行
くので、光軸がずれないという利点がある。FIG. 9 shows a sixth embodiment of the present invention, in which the core of the glass optical waveguide is inclined so as to be symmetrical with respect to the optical semiconductor element.
That is, in the figure, 51 is a glass optical waveguide, 52 is a plurality of cores arranged substantially in parallel with the glass optical waveguide 51, 53 is an end face of the glass optical waveguide 51, 54 is a spherical lens, and 55 is a path of an optical signal. . In this embodiment, even if overetching occurs when processing the end face 53, both end faces are equally shifted, so that there is an advantage that the optical axis does not shift.
【００３１】なお、これまで説明した実施例ではアレイ
状の光半導体素子の両側にガラス光導波路がある場合に
ついて説明したが、片側のみの場合及び光半導体素子の
代りにリチウムナイオベイト等の光機能素子を用いた場
合にも適用できることは言うまでもない。In the above-described embodiments, the case where the glass optical waveguides are provided on both sides of the optical semiconductor device in the form of an array has been described. However, only the optical semiconductor device on one side and the optical function such as lithium niobate are used instead of the optical semiconductor device. It goes without saying that the present invention can be applied to the case where an element is used.
【００３２】[0032]
【発明の効果】以上説明したように本発明によれば、略
並列に配置された複数のコアを有するガラス光導波路
と、略並列に配置され且つ前記ガラス光導波路の複数の
コアにそれぞれ光学的に結合される複数のコアを有する
アレイ状の光半導体素子とからなる光回路において、ガ
ラス光導波路の端面を、各コアの近傍部が該各コアの光
軸に直交する方向に対して傾き且つガラス光導波路のコ
アとこれに対応する光半導体素子のコアとの間隙が各コ
ア毎に等しくなるよう形成したため、ガラス光導波路及
びアレイ状の光半導体素子間の結合効率を悪化させるこ
となく、ガラス光導波路の端面による反射戻り光を大幅
に減少することができる。As described above, according to the present invention, a glass optical waveguide having a plurality of cores arranged substantially in parallel, and a plurality of cores of the glass optical waveguide arranged substantially in parallel, In an optical circuit comprising an array of optical semiconductor elements having a plurality of cores coupled to the end surface of the glass optical waveguide, the vicinity of each core is inclined with respect to a direction orthogonal to the optical axis of each core and Since the gap between the core of the glass optical waveguide and the core of the corresponding optical semiconductor element is formed so as to be equal for each core, the glass is not deteriorated in the coupling efficiency between the glass optical waveguide and the array-like optical semiconductor element. The return light reflected by the end face of the optical waveguide can be greatly reduced.
【００３３】また、本発明によれば、ガラス光導波路の
端面のコアの近傍部が少し奥に引っ込む形になるので、
光軸調整中に光半導体素子のコアをぶつけて破損する危
険性が少なくなり、組立時の歩留まり向上が期待でき
る。また、本光回路の性能は、主としてガラス光導波路
の端面の加工精度で決まるが、この端面はフォトリソグ
ラフィープロセスによって作製できるので、非常に高精
度に、しかも再現性良く製造でき、量産に適している。
また、本発明によれば、端面形状の工夫により、ガラス
光導波路及び光半導体素子間の距離を無調整化でき、さ
らにまた、端面が直線状のガラス光導波路に後から追加
加工して光半導体素子を挿入するようなことも可能であ
る。Further, according to the present invention, since the vicinity of the core on the end face of the glass optical waveguide is slightly retracted,
The risk of hitting and damaging the core of the optical semiconductor element during optical axis adjustment is reduced, and an improvement in the yield during assembly can be expected. The performance of this optical circuit is mainly determined by the processing accuracy of the end face of the glass optical waveguide. Since this end face can be manufactured by a photolithography process, it can be manufactured with very high accuracy and with good reproducibility, and is suitable for mass production. I have.
Further, according to the present invention, the distance between the glass optical waveguide and the optical semiconductor element can be made unadjustable by devising the end face shape, and furthermore, the optical semiconductor is further processed into a glass optical waveguide having a straight end face. It is also possible to insert an element.
【図１】本発明の光回路の第１の実施例を示す構成図FIG. 1 is a configuration diagram showing a first embodiment of an optical circuit of the present invention.
【図２】従来の光回路の一例を示す構成図FIG. 2 is a configuration diagram showing an example of a conventional optical circuit.
【図３】光の屈折のようすを示す説明図FIG. 3 is an explanatory diagram showing a state of refraction of light.
【図４】端面の角度に対する透過率及び反射減衰量を示
すグラフFIG. 4 is a graph showing transmittance and return loss with respect to an angle of an end face;
【図５】本発明の光回路の第２の実施例を示す構成図FIG. 5 is a configuration diagram showing a second embodiment of the optical circuit of the present invention.
【図６】本発明の光回路の第３の実施例を示す構成図FIG. 6 is a configuration diagram showing a third embodiment of the optical circuit of the present invention.
【図７】本発明の光回路の第４の実施例を示す構成図FIG. 7 is a configuration diagram showing a fourth embodiment of the optical circuit of the present invention.
【図８】本発明の光回路の第５の実施例を示す構成図FIG. 8 is a configuration diagram showing a fifth embodiment of the optical circuit of the present invention.
【図９】本発明の光回路の第６の実施例を示す構成図FIG. 9 is a configuration diagram showing a sixth embodiment of the optical circuit of the present invention.
４，４４…光半導体素子、５，４５…光半導体素子のコ
ア、１１，２１，３１，４１，５１…ガラス光導波路、
１２，２２，３２，４２，５２…ガラス光導波路のコ
ア、１３，２３，２３´，３３，４３，５３…ガラス光
導波路の端面、１４，２４，３５，４７，５５…光信号
の経路、２５，３４，５４…球レンズ。4, 44: optical semiconductor element; 5, 45: core of optical semiconductor element; 11, 21, 31, 41, 51: glass optical waveguide;
12, 22, 32, 42, 52 ... core of glass optical waveguide, 13, 23, 23 ', 33, 43, 53 ... end face of glass optical waveguide, 14, 24, 35, 47, 55 ... optical signal path, 25, 34, 54: spherical lens.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平５−157944（ＪＰ，Ａ) 特開 平２−195309（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G02B 6/42 - 6/43 G02B 6/12 - 6/14 G02B 6/30 - 6/35 G02B 6/26 - 6/27 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-157944 (JP, A) JP-A-2-195309 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) G02B 6/42-6/43 G02B 6/12-6/14 G02B 6/30-6/35 G02B 6/26-6/27
Claims (1)
ガラス光導波路と、略並列に配置され且つ前記ガラス光
導波路の複数のコアにそれぞれ光学的に結合される複数
のコアを有するアレイ状の光半導体素子とからなる光回
路において、ガラス光導波路とアレイ状の光半導体素子とは同一の基
板上に配置され、 ガラス光導波路の端面を、基板に対して垂直で、各コア
の近傍部が該各コアの光軸に直交する方向に対して傾き
且つガラス光導波路のコアとこれに対応する光半導体素
子のコアとの間隙が各コア毎に等しくなるよう形成した
ことを特徴とする光回路。1. An array comprising a glass optical waveguide having a plurality of cores arranged substantially in parallel, and a plurality of cores arranged substantially in parallel and optically coupled to the plurality of cores of the glass optical waveguide, respectively. In an optical circuit composed of optical semiconductor elements, the glass optical waveguide and the optical semiconductor
The glass optical waveguide is disposed on a plate, and the end face of the glass optical waveguide is perpendicular to the substrate, and the vicinity of each core is inclined with respect to a direction orthogonal to the optical axis of each core and corresponds to the core of the glass optical waveguide. An optical circuit characterized in that a gap between a core of an optical semiconductor element to be formed and a core thereof is made equal for each core.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1552393A JP3147564B2 (en) | 1993-02-02 | 1993-02-02 | Optical circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1552393A JP3147564B2 (en) | 1993-02-02 | 1993-02-02 | Optical circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06230237A JPH06230237A (en) | 1994-08-19 |
| JP3147564B2 true JP3147564B2 (en) | 2001-03-19 |
Family
ID=11891177
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1552393A Expired - Lifetime JP3147564B2 (en) | 1993-02-02 | 1993-02-02 | Optical circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3147564B2 (en) |
Cited By (1)
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|---|---|---|---|---|
| US20140348461A1 (en) * | 2013-05-21 | 2014-11-27 | International Business Machines Corporation | Optical component with angled-facet waveguide |
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|---|---|---|---|---|
| JPH1130722A (en) * | 1997-07-11 | 1999-02-02 | Nippon Telegr & Teleph Corp <Ntt> | Optical module |
| JP3337403B2 (en) | 1997-09-19 | 2002-10-21 | 日本電信電話株式会社 | Frequency stabilized laser |
| KR100357851B1 (en) * | 2000-12-19 | 2002-10-25 | 삼성전자 주식회사 | Apparatus of reducing loss variation in a multi-channel optical module by means of mode dismatch |
| JP3517657B2 (en) | 2002-07-03 | 2004-04-12 | Ｔｄｋ株式会社 | Embedded optical non-reciprocal circuit device |
| WO2007077419A1 (en) * | 2006-01-05 | 2007-07-12 | University Of Southampton | Optical fibre with angled core |
| JP2010526344A (en) * | 2007-05-02 | 2010-07-29 | ホーヤ コーポレイション ユーエスエイ | Optical elements for free space propagation between optical waveguides and other optical waveguides, components and devices |
| JP2018092152A (en) * | 2016-11-30 | 2018-06-14 | 株式会社フジクラ | Ferrule structure body, ferrule structure body with fiber, and manufacturing method of ferrule structure body with fiber |
| JP2019040040A (en) * | 2017-08-24 | 2019-03-14 | 富士通株式会社 | Optical functional module, optical transceiver using the same, and method of manufacturing optical functional module |
| US11740407B2 (en) * | 2021-10-22 | 2023-08-29 | Voyant Photonics, Inc. | Etched facet coupling for flip-chip to photonics chip bonding |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02195309A (en) * | 1989-01-24 | 1990-08-01 | Nippon Telegr & Teleph Corp <Ntt> | Optical coupling element |
| JPH05157944A (en) * | 1991-12-03 | 1993-06-25 | Nippon Hoso Kyokai <Nhk> | Two-way optical device |
-
1993
- 1993-02-02 JP JP1552393A patent/JP3147564B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140348461A1 (en) * | 2013-05-21 | 2014-11-27 | International Business Machines Corporation | Optical component with angled-facet waveguide |
| US9645311B2 (en) * | 2013-05-21 | 2017-05-09 | International Business Machines Corporation | Optical component with angled-facet waveguide |
| US9857531B2 (en) | 2013-05-21 | 2018-01-02 | International Business Machines Corporation | Optical component with angled-facet waveguide |
| US9927574B2 (en) | 2013-05-21 | 2018-03-27 | International Business Machines Corporation | Optical component with angled-facet waveguide |
| US10082625B2 (en) | 2013-05-21 | 2018-09-25 | International Business Machines Corporation | Optical component with angled-facet waveguide |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06230237A (en) | 1994-08-19 |
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