JPH0374364B2 - - Google Patents
Info
- Publication number
- JPH0374364B2 JPH0374364B2 JP58105401A JP10540183A JPH0374364B2 JP H0374364 B2 JPH0374364 B2 JP H0374364B2 JP 58105401 A JP58105401 A JP 58105401A JP 10540183 A JP10540183 A JP 10540183A JP H0374364 B2 JPH0374364 B2 JP H0374364B2
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- screen
- optical
- lens
- gradient index
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000003287 optical effect Effects 0.000 claims description 31
- 239000013307 optical fiber Substances 0.000 claims description 31
- 238000003384 imaging method Methods 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 10
- 239000011295 pitch Substances 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920003217 poly(methylsilsesquioxane) Polymers 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 239000012780 transparent material Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/32—Optical coupling means having lens focusing means positioned between opposed fibre ends
Description
【発明の詳細な説明】
本発明は、屈折率分布型レンズと光フアイバと
の光軸を合わせる方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for aligning the optical axes of a gradient index lens and an optical fiber.
屈折率分布型レンズと光フアイバとを組合わせ
て、光フアイバからの出射光を平行光にしたり、
或いは平行光を集束させて光フアイバ内へ入射さ
せたりする装置は、この様な装置を１対用意し、
これらを所定の間隔で互いに対向させて光フアイ
バ同士を光学的に接続する為の光フアイバコネク
タとしたり、或いは装置同士の間にプリズムや干
渉膜フイルタ等を挿入して光分岐器や光分波器等
とすることによつて、有用な光通信用機器を提供
することができる。しかしその為には、屈折率分
布型レンズと光フアイバとの高精度な光軸合わせ
の技術が必要である。 By combining a gradient index lens and an optical fiber, the light emitted from the optical fiber can be made into parallel light.
Alternatively, for a device that focuses parallel light and makes it enter an optical fiber, a pair of such devices is prepared,
These can be made to face each other at a predetermined interval to form an optical fiber connector for optically connecting optical fibers, or a prism or interference film filter can be inserted between the devices to create an optical splitter or optical demultiplexer. By making it into a device etc., useful optical communication equipment can be provided. However, this requires a technique for highly accurate optical axis alignment between the gradient index lens and the optical fiber.
そこで我々は、先に特願昭56−33470号（特開
昭57−147610号）に於いて、この様な光軸合わせ
を行う方法を提案した。その方法は、第１図の様
にして行うものである。即ち、光の蛇行周期の1/
４ピツチ（1/4ピツチの奇数倍でもよい）の長さを
有する屈折率分布型レンズ１の一方の端面１ａか
ら平行光２を入射させ、レンズ１の他方の端面１
ｂに集束した光を光フアイバ３内へ導く。そし
て、検出器４とマイクロコンピユータを含む制御
機構５とによつて光の強度を測定しつつ、ステツ
プモータで駆動される三軸移動機構６によつて、
光フアイバ３をレンズ１の光軸に垂直な平面内で
互いに直交する二方向へ移動させ、最大強度の光
を得られる位置で光フアイバ３を停止する様にし
ている。 Therefore, we previously proposed a method for performing such optical axis alignment in Japanese Patent Application No. 56-33470 (Japanese Unexamined Patent Publication No. 57-147610). The method is as shown in FIG. In other words, 1/ of the meandering period of light
Parallel light 2 is incident from one end surface 1a of a gradient index lens 1 having a length of 4 pitches (an odd number multiple of 1/4 pitch), and the parallel light 2 is incident on the other end surface 1a of the lens 1.
The light focused on point b is guided into the optical fiber 3. While the intensity of the light is measured by a detector 4 and a control mechanism 5 including a microcomputer, a three-axis movement mechanism 6 driven by a step motor measures the intensity of the light.
The optical fiber 3 is moved in two mutually perpendicular directions within a plane perpendicular to the optical axis of the lens 1, and is stopped at a position where the maximum intensity of light can be obtained.
屈折率分布型レンズ１は、ガラスや合成樹脂等
の透明な材料で円柱状に形成され、その屈折率が
軸心位置で最大であり且つ半径方向へ距離の２乗
に略比例して減少している為に、光の入射端面が
平面であつてもレンズ作用を有しており、光が軸
心を中心として蛇行しながら進むレンズである。 The gradient index lens 1 is made of a transparent material such as glass or synthetic resin and has a cylindrical shape, and its refractive index is maximum at the axial center position and decreases in the radial direction approximately in proportion to the square of the distance. Therefore, even if the light incident end face is flat, it has a lens effect, and the light travels in a meandering manner around the axis.
ところで、平行光２が端面１ｂで集束してでき
るスポツト径は数μmであるのに対し、光フアイ
バ３がステツプ型である場合、そのコア径は通常
は50μm以上である。そして、平行光２のスポツ
トがコアと対向してさえいれば、検出器４で検出
される光の強度は殆んど変わらず、強度が最大で
ある位置は１つの点ではなく或る広がりを有する
面となる。また、光フアイバ３がステツプ型では
なくグレーデツド型であつても、その屈折率分布
の勾配が緩やかな場合は、同様の結果となる。従
つて、上述の様な従来の方法では、光の強度分布
の正確な中心位置を求めることができず、レンズ
１と光フアイバ３との光軸合わせの精度が良くな
い。 By the way, the diameter of the spot formed by the collimated light 2 converging at the end face 1b is several μm, whereas when the optical fiber 3 is of a step type, its core diameter is usually 50 μm or more. As long as the spot of the parallel light 2 faces the core, the intensity of the light detected by the detector 4 will hardly change, and the position where the intensity is maximum will not be at one point but over a certain spread. It becomes a surface that has. Further, even if the optical fiber 3 is not a step type but a graded type, the same result will be obtained if the gradient of the refractive index distribution is gentle. Therefore, in the conventional method as described above, it is not possible to determine the accurate center position of the light intensity distribution, and the accuracy of optical axis alignment between the lens 1 and the optical fiber 3 is not good.
本発明は、この様な問題点に鑑み、屈折率分布
型レンズと光フアイバとの光軸を高精度に合わせ
ることができる方法を提供することを目的として
いる。 In view of these problems, it is an object of the present invention to provide a method that can align the optical axes of a gradient index lens and an optical fiber with high precision.
以下、本発明の一実施例を第２図を参照しなが
ら説明する。 An embodiment of the present invention will be described below with reference to FIG.
この実施例に於いては、屈折率分布型レンズ１
から約２ｍの距離にスクリーン１１を配置し、こ
のスクリーン１１に微小な孔１２を設ける。そし
て、光学的真直度測定器（図示せず）等を使用し
つつレンズ１とスクリーン１１とを相対的に移動
させることによつて、レンズ１の光軸とスクリー
ン１１との交点、つまり光軸中心位置X0，Y0を
孔１２に一致させる。次いで、スクリーン１１の
背面側から孔１２を通るスポツトビーム１３を出
射させ、テレビカメラ等の撮像装置１４によつて
スクリーン１１を撮像し、この撮像装置１４内で
の操作によつて検出したスポツトビーム１３の光
点位置を、光軸中心位置X0，Y0として制御機構
５に記憶させる。 In this embodiment, a gradient index lens 1
A screen 11 is placed at a distance of about 2 m from the center, and a minute hole 12 is provided in the screen 11. Then, by relatively moving the lens 1 and the screen 11 using an optical straightness measuring device (not shown), etc., the intersection of the optical axis of the lens 1 and the screen 11, that is, the optical axis The center positions X 0 and Y 0 are aligned with the hole 12 . Next, the spot beam 13 passing through the hole 12 is emitted from the back side of the screen 11, the screen 11 is imaged by an imaging device 14 such as a television camera, and the spot beam detected by the operation within the imaging device 14 is The light spot positions of No. 13 are stored in the control mechanism 5 as optical axis center positions X 0 and Y 0 .
この様な状態で、光フアイバ３にHe−Neレー
ザ光を入射させる。このHe−Neレーザ光は、端
面１ａからレンズ１内へ入射し、端面１ｂから平
行光１５としてスクリーン１１上へ投射される。
このとき、レンズ１と光フアイバ３との光軸がず
れていれば、平行光１５はレンズ１の光軸に対し
てある角度をもつて出射する。 In this state, a He--Ne laser beam is made to enter the optical fiber 3. This He--Ne laser light enters into the lens 1 from the end surface 1a, and is projected onto the screen 11 as parallel light 15 from the end surface 1b.
At this time, if the optical axes of the lens 1 and the optical fiber 3 are misaligned, the parallel light 15 will be emitted at a certain angle with respect to the optical axis of the lens 1.
次いで、撮像装置１４によつてスクリーン１１
を撮像し、画像を制御機構５に入力すると、制御
機構５はこの画像を走査して光の強度分布から平
行光１５のスクリーン１１上に於けるビームスポ
ツトの中心位置Ｘ，Ｙを計算によつて求める。制
御機構５は、更に、光軸中心位置X0，Y0に対す
る上記ビームスポツトの中心位置Ｘ，Ｙのズレ量
を計算し、このズレ量の1/2の値を三軸移動機構
６へ入力する。 Next, the screen 11 is captured by the imaging device 14.
When the image is captured and inputted to the control mechanism 5, the control mechanism 5 scans this image and calculates the center position X, Y of the beam spot on the screen 11 of the parallel light 15 from the light intensity distribution. I ask for it. The control mechanism 5 further calculates the amount of deviation of the center positions X and Y of the beam spot with respect to the optical axis center positions X 0 and Y 0 , and inputs a value of 1/2 of this deviation amount to the three-axis movement mechanism 6. do.
三軸移動機構６は、レンズ１の光軸に垂直な面
内で互いに直交する二方向へ、つまりＸ軸方向と
Ｙ軸方向とへ、制御機構５から入力された値だ
け、光フアイバ３をレンズ１に対して相対的に移
動させる。 The three-axis moving mechanism 6 moves the optical fiber 3 in two mutually orthogonal directions in a plane perpendicular to the optical axis of the lens 1, that is, in the X-axis direction and the Y-axis direction, by the value input from the control mechanism 5. It is moved relative to the lens 1.
撮像装置１４によつてスクリーン１１を撮像し
平行光１５のビームスポツトの中心位置Ｘ，Ｙを
求める工程から、光軸中心位置X0，Y0に対する
ズレ量の1/2の量だけ光フアイバ３を二方向へ移
動させる工程までを繰り返して行い、中心位置
Ｘ，Ｙが光軸中心位置X0，Y0に実質的に等しく
なつた時点で全工程が終了する。 From the step of imaging the screen 11 with the imaging device 14 and determining the center positions X and Y of the beam spot of the parallel light 15, the optical fiber 3 is moved by half the amount of deviation from the optical axis center positions X 0 and Y 0 . The steps up to moving the optical axis in two directions are repeated, and the entire process ends when the center positions X and Y become substantially equal to the optical axis center positions X 0 and Y 0 .
本実施例に於いては、以上の様な全工程を約10
秒で終了させることができた。全工程が終了した
後でレンズ１と光フアイバ３とを接着剤等によつ
て互いに固定すると、両者は光軸が一致した状態
で結合される。 In this example, the entire process as described above was carried out approximately 10 times.
I was able to finish it in seconds. When the lens 1 and the optical fiber 3 are fixed to each other with an adhesive or the like after all the steps are completed, they are combined with their optical axes aligned.
なお、以上の方法に於いては、平行光１５のス
クリーン１１上に於けるビームスポツトの中心位
置Ｘ，Ｙの光軸中心位置X0，Y0に対するズレの
内、撮像装置１４によつて検出される成分をでき
るだけ大きくする為に、レンズ１の光軸と撮像装
置１４との角度はできるだけ小さい値がよく、本
実施例に於いては約10゜とした。 In addition, in the above method, the deviation of the center positions X, Y of the beam spot of the parallel light 15 on the screen 11 with respect to the optical axis center positions X 0 , Y 0 is detected by the imaging device 14. In order to maximize the component that is detected, the angle between the optical axis of the lens 1 and the image pickup device 14 should be as small as possible, and in this embodiment, it was set to about 10 degrees.
以上の様な実施例に於いては、平行光１５のス
クリーン１１上に於けるビームスポツトの中心位
置Ｘ，Ｙの光軸中心位置X0，Y0に対するズレ量
を撮像装置１４及び制御機構５によつて求め、こ
の結果に基づく光フアイバ３の移動を三軸移動機
構６によつて行う様にしているが、これらは共に
約1μmの精度を有している。従つて、レンズ１と
光フアイバ３との光軸を、従来例よりも高精度に
合わせることができる。 In the embodiments described above, the amount of deviation of the center positions X, Y of the beam spots of the parallel light 15 on the screen 11 with respect to the optical axis center positions X 0 , Y 0 is determined by the imaging device 14 and the control mechanism 5. Based on this result, the optical fiber 3 is moved by a three-axis movement mechanism 6, both of which have an accuracy of about 1 μm. Therefore, the optical axes of the lens 1 and the optical fiber 3 can be aligned with higher precision than in the conventional example.
また、上記の実施例に於いては、撮像装置１４
及び制御機構５によつて求めたズレ量の1/2に相
当する量だけ、三軸移動機構６によつて光フアイ
バ３を移動する様にしているので、光フアイバ３
はＸ軸方向及びＹ軸方向の同一方向へのみ移動さ
れ、逆方向へ移動されることはない。従つて、三
軸移動機構６の歯車のバツクラツシユの影響を受
けず、このことによつてもレンズ１と光フアイバ
３との光軸を高精度に合わせることができる。 Further, in the above embodiment, the imaging device 14
Since the optical fiber 3 is moved by the triaxial movement mechanism 6 by an amount corresponding to 1/2 of the amount of deviation determined by the control mechanism 5, the optical fiber 3
is moved only in the same direction of the X-axis direction and the Y-axis direction, and is not moved in the opposite direction. Therefore, the optical axis of the lens 1 and the optical fiber 3 can be aligned with high precision without being affected by the backlash of the gears of the three-axis moving mechanism 6.
以上、本発明を一実施例に基づいて説明した
が、本発明はこの実施例に限定されるものではな
く、各種の変更が可能である。 Although the present invention has been described above based on one embodiment, the present invention is not limited to this embodiment, and various modifications are possible.
例えば、上記の実施例に於いては、１回の工程
で光フアイバ３をレンズ１に対して相対的に移動
させる量は、撮像装置１４及び制御機構５によつ
て求めたズレ量の1/2に相当する量であるが、こ
の量は上記ズレ量と同等またはそれよりも小さい
値の範囲内で任意に設定することができる。しか
しその場合でも、バツクラツシユ誤差と作業時間
とを考慮すると、上記移動量は、上記ズレ量の30
〜90％の範囲内とするのが望ましい。 For example, in the above embodiment, the amount by which the optical fiber 3 is moved relative to the lens 1 in one process is 1/1/2 of the amount of deviation determined by the imaging device 14 and the control mechanism 5. This amount corresponds to 2, but this amount can be arbitrarily set within the range of a value equal to or smaller than the above deviation amount. However, even in that case, considering the backlash error and work time, the above movement amount is 30% of the above shift amount.
It is desirable that it be within the range of ~90%.
上述の如く、本発明は、屈折率分布型レンズか
らの平行光をスクリーン上に投射し、この投射さ
れた平行光の中心位置と基準となる位置とのズレ
を測定することによつて、屈折率分布型レンズと
光フアイバとの光軸のズレを求める様にしてい
る。従つて、屈折率分布型レンズと光フアイバと
の光軸に僅からズレがあつても、スクリーン上で
はこのズレが拡大される。しかも、このズレか
ら、屈折率分布型レンズに対して光フアイバを相
対的に移動させるべき方向と距離とを、定量的に
求めることができる。このため、短時間で互いの
光軸を高精度に合わせることができる。 As described above, the present invention projects parallel light from a gradient index lens onto a screen and measures the deviation between the center position of the projected parallel light and a reference position, thereby measuring refraction. The optical axis deviation between the rate distribution lens and the optical fiber is determined. Therefore, even if there is a slight deviation between the optical axes of the gradient index lens and the optical fiber, this deviation will be magnified on the screen. Moreover, from this deviation, the direction and distance in which the optical fiber should be moved relative to the gradient index lens can be determined quantitatively. Therefore, the mutual optical axes can be aligned with high precision in a short time.
第１図は本発明の従来例を実施する為の装置を
示す概略的な側面図、第２図は本発明の一実施例
を実施する為の装置を示す概略的な側面図であ
る。
なお図面に用いられている符号に於いて、１…
…屈折率分布型レンズ、３……光フアイバ、１１
……スクリーン、１５……平行光である。
FIG. 1 is a schematic side view showing an apparatus for implementing a conventional example of the present invention, and FIG. 2 is a schematic side view showing an apparatus for implementing an embodiment of the present invention. Regarding the symbols used in the drawings, 1...
...Gradient index lens, 3...Optical fiber, 11
... Screen, 15 ... Parallel light.
Claims (1)
交点を求める工程と、光フアイバから前記屈折率
分布型レンズの一方の端面に光を入射させ他方の
端面から平行光を前記スクリーン上へ投射する工
程と、前記スクリーンを撮像し画像を走査して光
の強度分布から前記平行光の前記スクリーン上に
於けるビームスポツトの形状を求める工程と、前
記形状に基きこの形状の中心位置を計算によつて
求める工程と、前記交点に対する前記中心位置の
ズレ量を計算によつて求める工程と、前記ズレ量
がなくなるまで前記光フアイバを前記屈折率分布
型レンズに対して相対的に移動させる工程とを
夫々具備する屈折率分布型レンズと光フアイバと
の光軸を合わせる方法。1. Determining the intersection of the optical axis of the gradient index lens and the screen, and injecting light from an optical fiber into one end surface of the gradient index lens and projecting parallel light from the other end surface onto the screen. a step of imaging the screen and scanning the image to determine the shape of the beam spot of the parallel light on the screen from the light intensity distribution; and a step of calculating the center position of the shape based on the shape. a step of calculating the amount of deviation of the center position with respect to the intersection point, and a step of moving the optical fiber relative to the gradient index lens until the amount of deviation disappears. A method of aligning the optical axes of the gradient index lens and optical fiber, respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10540183A JPS59229515A (en) | 1983-06-13 | 1983-06-13 | Method for aligning optical axis of distributed index lens and optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10540183A JPS59229515A (en) | 1983-06-13 | 1983-06-13 | Method for aligning optical axis of distributed index lens and optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59229515A JPS59229515A (en) | 1984-12-24 |
| JPH0374364B2 true JPH0374364B2 (en) | 1991-11-26 |
Family
ID=14406602
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10540183A Granted JPS59229515A (en) | 1983-06-13 | 1983-06-13 | Method for aligning optical axis of distributed index lens and optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59229515A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4637683A (en) * | 1985-01-28 | 1987-01-20 | Trw Inc. | Method for aligning optical fiber connectors |
| GB2175411B (en) * | 1985-05-16 | 1988-08-03 | Stc Plc | Silica rod lens optical fibre terminations |
| US4772123A (en) * | 1986-11-24 | 1988-09-20 | American Telephone And Telegraph Company, At&T Bell Laboratories | Alignment of optical components |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5515107A (en) * | 1978-07-17 | 1980-02-02 | Nec Corp | Axial aligning method of lens |
| JPS5784412A (en) * | 1980-11-14 | 1982-05-26 | Nippon Sheet Glass Co Ltd | Optical axis aligning method of bar-like lens body and optical fiber |
-
1983
- 1983-06-13 JP JP10540183A patent/JPS59229515A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5515107A (en) * | 1978-07-17 | 1980-02-02 | Nec Corp | Axial aligning method of lens |
| JPS5784412A (en) * | 1980-11-14 | 1982-05-26 | Nippon Sheet Glass Co Ltd | Optical axis aligning method of bar-like lens body and optical fiber |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59229515A (en) | 1984-12-24 |
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