JPH03273208A - Semiconductor laser module - Google Patents
Semiconductor laser moduleInfo
- Publication number
- JPH03273208A JPH03273208A JP7206890A JP7206890A JPH03273208A JP H03273208 A JPH03273208 A JP H03273208A JP 7206890 A JP7206890 A JP 7206890A JP 7206890 A JP7206890 A JP 7206890A JP H03273208 A JPH03273208 A JP H03273208A
- Authority
- JP
- Japan
- Prior art keywords
- light
- semiconductor laser
- faraday rotator
- lens
- photodiode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000004065 semiconductor Substances 0.000 title claims abstract description 30
- 239000013307 optical fiber Substances 0.000 claims abstract description 6
- 239000000463 material Substances 0.000 claims abstract description 4
- 238000012544 monitoring process Methods 0.000 claims description 4
- 230000003287 optical effect Effects 0.000 abstract description 19
- 238000004519 manufacturing process Methods 0.000 abstract description 6
- 230000010287 polarization Effects 0.000 abstract description 4
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 238000004804 winding Methods 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000005259 measurement Methods 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
- G02B6/42—Coupling light guides with opto-electronic elements
- G02B6/4201—Packages, e.g. shape, construction, internal or external details
- G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
- G02B6/4207—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms with optical elements reducing the sensitivity to optical feedback
- G02B6/4208—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms with optical elements reducing the sensitivity to optical feedback using non-reciprocal elements or birefringent plates, i.e. quasi-isolators
- G02B6/4209—Optical features
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Semiconductor Lasers (AREA)
- Optical Couplings Of Light Guides (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は光通信、光計測等に適用され、電気信号を光信
号に変換する半導体レーザモジュールに関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor laser module that is applied to optical communication, optical measurement, etc., and converts an electrical signal into an optical signal.
〔従来の技術：・
従来、高速ＰＣＭ伝送やアナログ直接変調による画像伝
送システムでは、半導体レーザが用いられることはよく
知られている。しかし、このようなンステムでは光コネ
クタや他の光デバイス等からの反射光が半導体レーザに
再注入して生じる反射雑音の影響が大きく、このため反
射光の再注入を阻止するアイソレータを内蔵した半導体
レーザモジュールが開発されている。[Conventional technology: It is well known that semiconductor lasers are conventionally used in image transmission systems using high-speed PCM transmission or analog direct modulation. However, in such systems, the influence of reflection noise caused by the reinjection of reflected light from optical connectors and other optical devices into the semiconductor laser is significant, so semiconductors with built-in isolators to prevent the reinjection of reflected light have a large effect. A laser module has been developed.
第２図は、このような従来の光アイソレータ内蔵半導体
レーザモジュールの構成を示したものである。半導体レ
ーザ１の出射光は、レンズ２により平行光に変換された
後、偏光子３および４５゜ファラデー回転子４ならびに
検光子５から構成される光アイソレータを経て、レンズ
６により収束され、ファイバ７に結合される構成となっ
ており、反射光の再注入を阻止するようになっている。FIG. 2 shows the configuration of such a conventional semiconductor laser module with a built-in optical isolator. The emitted light from the semiconductor laser 1 is converted into parallel light by a lens 2, passes through an optical isolator consisting of a polarizer 3, a 45° Faraday rotator 4, and an analyzer 5, is converged by a lens 6, and is transmitted to a fiber 7. The structure is such that the reflected light is prevented from being reinjected.
ところが、上述した従来の光アイソレータ内蔵の半導体
レーザモジュールでは、半導体レーザからの出射光が第
１のレンズ２により平行光に変換され、偏光子３および
４５°フアラデ一回転子４ならびに検光子５から構成さ
れる光アイソレータを経て、第２のレンズ６により収束
され、ファイバ７に結合される構成となっており、４５
°フアラデ一回転子４にはマグネット等により固定の直
流磁界が印加されている。このため、半導体レーザモジ
ュールを構成するうえで、偏光子３および検光子５の光
学面を調整するのに高精度が要され、製作難度が極めて
高く、製作時間も多く必要とする等の問題がある。However, in the above-described conventional semiconductor laser module with a built-in optical isolator, the light emitted from the semiconductor laser is converted into parallel light by the first lens 2, and the light emitted from the semiconductor laser is converted into parallel light by the polarizer 3, the 45° Farade rotator 4, and the analyzer 5. After passing through an optical isolator, it is converged by a second lens 6 and coupled to a fiber 7.
A fixed DC magnetic field is applied to the Farade rotor 4 by a magnet or the like. For this reason, when constructing a semiconductor laser module, high precision is required to adjust the optical surfaces of the polarizer 3 and analyzer 5, which causes problems such as extremely high manufacturing difficulty and a long manufacturing time. be.
本発明はこのような事情に鑑みてなされたもので、製作
時のファラデー回転子の光軸調整に対する難度の軽減お
よび自由度の拡大により、製作時間の短縮等が図れる半
導体レーザモジュールを提供することを目的とする。The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a semiconductor laser module that can shorten the manufacturing time by reducing the difficulty in adjusting the optical axis of a Faraday rotator during manufacturing and increasing the degree of freedom. With the goal.
本発明は、半導体レーザと、この半導体レーザから出射
されるレーザ光を所定の直径の平行光に変換する第１の
レンズと、平行光の一部を反射戻り光として分離する直
角プリズムと、異常光の移動距離が平行光の所定の直径
以上となる複屈折材料を用いた偏光子と、回転角を変更
する手段を備えたファラデー回転子と、偏向面が偏光子
のそれに対して略４５°傾いた検光子と、平行光を収束
する第２のレンズと、収束光が出射される光ファイバと
、直角プリズムで分離された反射戻り光をモニタする手
段とを備え、これによりファラデー回転子の光軸の調整
難度を低減できると共に、フィードバック制御が実現で
き、上述した目的を達成するもである。The present invention provides a semiconductor laser, a first lens that converts laser light emitted from the semiconductor laser into parallel light of a predetermined diameter, a right-angle prism that separates a part of the parallel light as reflected return light, and an abnormality. A polarizer using a birefringent material that allows light to travel a distance equal to or greater than a predetermined diameter of parallel light, a Faraday rotator equipped with means for changing the rotation angle, and a polarizer whose polarization plane is approximately 45 degrees with respect to that of the polarizer. It includes an inclined analyzer, a second lens that converges parallel light, an optical fiber from which the converged light is emitted, and a means for monitoring the reflected return light separated by a right-angle prism. The degree of difficulty in adjusting the optical axis can be reduced, feedback control can be realized, and the above-mentioned objects can be achieved.
なお、ファラデー回転子の回転角を変更する手段はコイ
ルとされる。Note that the means for changing the rotation angle of the Faraday rotator is a coil.
また、直角プリズムで分離された反射戻り光をモニタす
る手段は、フォトダイオードとされる。Further, the means for monitoring the reflected return light separated by the right-angle prism is a photodiode.
以下、本発明に係わる半導体レーザモジュールの一実施
例を第１図を参照して説明する。Hereinafter, one embodiment of a semiconductor laser module according to the present invention will be described with reference to FIG.
本実施例の半導体レーザモジュールは、半導体レーザ１
１と、この半導体レーザ１１から出射されるレーザ光を
所定の直径の平行光に変換する第１のレンズ１２と、直
角プリズム１３と、異常光の移動距離が平行光の所定の
直径以上となる複屈折材料を用いた偏光子１４と、ファ
ラデー回転子１５と、偏向面が偏光子１４のそれに対し
て略４５°傾いた検光子１６と、平行光を収束する第２
のレンズ１７と、光ファイバ１８と、直角プリズム１３
からの反射光をモニタし、その反射光に応じた光電流を
発生させるフォトダイオード１９と、ファラデー回転子
１５に巻かれ、フォトダイオード１９からの光電流に応
じて直流電流ｒが流され直流磁界Ｈを励起するコイル２
０とによって構成されている。The semiconductor laser module of this embodiment has a semiconductor laser 1
1, a first lens 12 that converts the laser light emitted from the semiconductor laser 11 into parallel light having a predetermined diameter, and a right angle prism 13, so that the traveling distance of the extraordinary light is equal to or greater than the predetermined diameter of the parallel light. A polarizer 14 using a birefringent material, a Faraday rotator 15, an analyzer 16 whose polarization plane is inclined at approximately 45 degrees with respect to that of the polarizer 14, and a second polarizer that converges parallel light.
lens 17, optical fiber 18, and right angle prism 13
A photodiode 19 that monitors the reflected light from the photodiode 19 and generates a photocurrent according to the reflected light; and a photodiode 19 that is wound around the Faraday rotator 15 and receives a direct current r in accordance with the photocurrent from the photodiode 19 to generate a direct current magnetic field. Coil 2 that excites H
0.
しかし、半導体レーザ１１の出射光は、第１のレンズ１
２により平行光に変換された後、直角プリズム１３を通
過して、偏光子１４およびファラデー回転子１５を経て
、検光子１６を通過し、第２のレンズ１７で収束され、
光ファイバ１８に入射される。その際、ファラデー回転
子１５には、直流電流Ｉを流すとｉＩＩ流磁界Ｈを励起
するコイル２０が巻かれているので、この直流電流■を
制御し、直流磁界Ｈを変化させると、ファラデー回転子
１５のファラデー回転角θは次の（１）式の関係を満足
して変化することが可能である。However, the light emitted from the semiconductor laser 11 is transmitted through the first lens 1.
2, the light passes through a right-angle prism 13, passes through a polarizer 14 and a Faraday rotator 15, passes through an analyzer 16, and is converged by a second lens 17.
The light is input into the optical fiber 18. At this time, since a coil 20 is wound around the Faraday rotator 15, which excites an III-flow magnetic field H when a DC current I is passed through it, when this DC current ■ is controlled and the DC magnetic field H is changed, the Faraday rotation The Faraday rotation angle θ of the child 15 can be changed while satisfying the relationship of the following equation (1).
θ＝ＶＨ・１ ・・・・・・（１）
（ｖ：ベルデ定数、１：ファラデー回転子１５の長さ）
いま、偏光子１４の前方（出射側）に反射点があり、反
射光が戻ってくるものとすると、反射光は直角プリズム
１３にて、半導体レーザ１１に入射されずフォトダイオ
ード１９に入射され、フォトダイオード１９に入射され
た反射光に応じた光電流が発生する。この光電流を外部
にてモニタし、その平均値を検出する回路を外部に設け
、またその検出電圧を電流に変換する制御回路をモジュ
ール外部に設け、ファラデー回転子１５にフィードバッ
クする構成とすると、反射戻り光がなくなるようにファ
ラデー回転子１５の回転角を自動的に最適に合わせ込む
ように動作する。θ=VH・1 (1) (v: Verdet constant, 1: length of Faraday rotator 15) Now, there is a reflection point in front of the polarizer 14 (output side), and the reflected light Assuming that the reflected light returns, the reflected light is not incident on the semiconductor laser 11 but is incident on the photodiode 19 at the right angle prism 13, and a photocurrent corresponding to the reflected light incident on the photodiode 19 is generated. If a circuit is provided externally to monitor this photocurrent and detect its average value, and a control circuit is provided externally to the module to convert the detected voltage into a current, and is fed back to the Faraday rotator 15, The rotation angle of the Faraday rotator 15 is automatically adjusted to the optimum value so that reflected return light is eliminated.
したがって、従来ではマグネット等により半固定状態で
、光学面の調整等の難度が高く、何等かの外部要因で軸
がずれても補償する手段がなかったのに対し、本実施例
では、反射戻り光のモニタが可能で、かつファラデー回
転子１５の回転角を連続的に変化可能としたので、製造
時のファラデー回転子の光軸の調整難度を低減できると
共に、フィードバック制御が実現でき、自由度の大きい
半導体レーザダイオードが実現できるようになる。Therefore, in the past, the optical surface was semi-fixed using magnets, etc., making it difficult to adjust the optical surface, and there was no way to compensate for axis deviation due to some external factor. Since the light can be monitored and the rotation angle of the Faraday rotator 15 can be changed continuously, the difficulty in adjusting the optical axis of the Faraday rotator during manufacturing can be reduced, and feedback control can be realized, increasing the degree of freedom. This makes it possible to realize semiconductor laser diodes with large diameters.
以上のように本発明によれば、モジュール内に前方の反
射戻り光のモニタができる直角プリズムとフォトダイオ
ード等とを設けると共に、光アイソレータのファラデー
回転子にコイル等を巻いた構成としたことで、ファラデ
ー回転子の光軸の調整難度を低減できると共に、フィー
ドバック制御が実現でき、自由度の大きい半導体レーザ
ダイオードが実現できるようになるという優れた効果が
奏される。As described above, according to the present invention, a rectangular prism, a photodiode, etc. that can monitor the forward reflected return light are provided in the module, and a coil etc. is wound around the Faraday rotator of the optical isolator. , the difficulty in adjusting the optical axis of the Faraday rotator can be reduced, feedback control can be realized, and a semiconductor laser diode with a large degree of freedom can be realized, which is an excellent effect.
第１図は本発明の一実施例を示す構成図、第２図は従来
例を示す構成図である。
１１・・・・・・半導体レーザ、１２・・・・・・レン
ズ、１３・・・・・・直角プリズム、１４・・・・・・
偏光子、１５・・・・・・ファラデー転子、１６・・・
・・・検光子、１７・・・・・・レンズ、
１８・・・・・・光ファイバ、
１９・・・フォトダイオード、
２０・・・・・・コイル。FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional example. 11... Semiconductor laser, 12... Lens, 13... Right angle prism, 14...
Polarizer, 15... Faraday trochanter, 16...
...Analyzer, 17...Lens, 18...Optical fiber, 19...Photodiode, 20...Coil.
Claims (1)
の平行光に変換する第１のレンズと、平行光の一部を反
射戻り光として分離する直角プリズムと、 異常光の移動距離が平行光の所定の直径以上となる複屈
折材料を用いた偏光子と、 回転角を変更する手段を備えたファラデー回転子と、 偏向面が前記偏光子のそれに対して略４５゜傾いた検光
子と、 平行光を収束する第２のレンズと、 収束光が出射される光ファイバと、 前記直角プリズムで分離された反射戻り光をモニタする
手段 とを具備することを特徴とする半導体レーザモジュール
。 ２、ファラデー回転子の回転角を変更する手段はコイル
であることを特徴とする請求項１記載の半導体レーザモ
ジュール。 ３、直角プリズムで分離された反射戻り光をモニタする
手段は、フォトダイオードであることを特徴とする請求
項１記載の半導体レーザモジュール。[Claims] 1. A semiconductor laser, a first lens that converts the laser light emitted from the semiconductor laser into parallel light of a predetermined diameter, and a right angle lens that separates a part of the parallel light as reflected return light. a prism; a polarizer using a birefringent material such that the travel distance of the extraordinary light is equal to or greater than a predetermined diameter of the parallel light; a Faraday rotator having a means for changing the rotation angle; The analyzer is provided with an analyzer tilted at approximately 45 degrees with respect to the analyzer, a second lens that converges parallel light, an optical fiber from which the converged light is emitted, and means for monitoring reflected return light separated by the right angle prism. A semiconductor laser module characterized by: 2. The semiconductor laser module according to claim 1, wherein the means for changing the rotation angle of the Faraday rotator is a coil. 3. The semiconductor laser module according to claim 1, wherein the means for monitoring the reflected return light separated by the right-angle prism is a photodiode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7206890A JPH03273208A (en) | 1990-03-23 | 1990-03-23 | Semiconductor laser module |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7206890A JPH03273208A (en) | 1990-03-23 | 1990-03-23 | Semiconductor laser module |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03273208A true JPH03273208A (en) | 1991-12-04 |
Family
ID=13478716
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7206890A Pending JPH03273208A (en) | 1990-03-23 | 1990-03-23 | Semiconductor laser module |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03273208A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999030205A1 (en) * | 1997-12-09 | 1999-06-17 | Samsung Electronics Co., Ltd. | Optical attenuator using isolator and optical communications system including the same |
| DE10001389B4 (en) * | 1999-01-14 | 2004-12-30 | Samsung Electronics Co., Ltd., Suwon | Optical attenuation isolator |
| CN103364894A (en) * | 2012-03-30 | 2013-10-23 | 富士通株式会社 | Optical transmitter, optical module, and optical connector |
-
1990
- 1990-03-23 JP JP7206890A patent/JPH03273208A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999030205A1 (en) * | 1997-12-09 | 1999-06-17 | Samsung Electronics Co., Ltd. | Optical attenuator using isolator and optical communications system including the same |
| US6441944B1 (en) | 1997-12-09 | 2002-08-27 | Samsung Electronics Co., Ltd. | Optical attenuator using isolator and optical communications system including the same |
| AU751728B2 (en) * | 1997-12-09 | 2002-08-29 | Samsung Electronics Co., Ltd. | Optical attenuator using isolator and optical communications system including the same |
| DE10001389B4 (en) * | 1999-01-14 | 2004-12-30 | Samsung Electronics Co., Ltd., Suwon | Optical attenuation isolator |
| CN103364894A (en) * | 2012-03-30 | 2013-10-23 | 富士通株式会社 | Optical transmitter, optical module, and optical connector |
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