JPH01129483A - Light amplifier - Google Patents

Light amplifier

Info

Publication number
JPH01129483A
JPH01129483A JP62287655A JP28765587A JPH01129483A JP H01129483 A JPH01129483 A JP H01129483A JP 62287655 A JP62287655 A JP 62287655A JP 28765587 A JP28765587 A JP 28765587A JP H01129483 A JPH01129483 A JP H01129483A
Authority
JP
Japan
Prior art keywords
light
optical
amplifier
semiconductor laser
injected
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
Application number
JP62287655A
Other languages
Japanese (ja)
Inventor
Masabumi Koga
正文 古賀
Masahiko Jinno
正彦 神野
Takao Matsumoto
松本　隆男
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Telegraph and Telephone Corp
Original Assignee
Nippon Telegraph and Telephone Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nippon Telegraph and Telephone Corp filed Critical Nippon Telegraph and Telephone Corp
Priority to JP62287655A priority Critical patent/JPH01129483A/en
Publication of JPH01129483A publication Critical patent/JPH01129483A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/50—Amplifier structures not provided for in groups H01S5/02 - H01S5/30
    • H01S5/5009—Amplifier structures not provided for in groups H01S5/02 - H01S5/30 the arrangement being polarisation-insensitive
    • H01S5/5018—Amplifier structures not provided for in groups H01S5/02 - H01S5/30 the arrangement being polarisation-insensitive using two or more amplifiers or multiple passes through the same amplifier
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/09—Processes or apparatus for excitation, e.g. pumping
    • H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • H01S3/0941—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a laser diode
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/23—Arrangements of two or more lasers not provided for in groups H01S3/02 - H01S3/22, e.g. tandem arrangements of separate active media
    • H01S3/2308—Amplifier arrangements, e.g. MOPA
    • H01S3/2316—Cascaded amplifiers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/005—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping
    • H01S5/0078—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping for frequency filtering

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Semiconductor Lasers (AREA)
  • Optical Communication System (AREA)

Abstract

PURPOSE:To obtain a constant gain with respect to injected light without depending upon the state of polarization of the light by mutually crossing the thickness directions of active layers in two semiconductor laser elements arranged onto the same optical path in a cascade manner at right angles to the deflection of light on the optical path. CONSTITUTION:Light propagated in a single-mode optical fiber 1 is injected to an active layer 4 in a light amplifier 3 through a SELFOC lens 2, and amplified respectively to TE waves and TM waves only by gains GTE1, GTM1 and output. Amplified light is injected to an active layer 7 in a light amplifier 6 through a lens 5'', and amplified respectively only by gains GTE2, GTM2 and output. When an optical isolator 10 having no polarized wave dependency is inserted between the light amplifiers 3, 6, light returns to the light amplifier 3 at a pre-stage owing to the incompleteness of a nonreflective film, thus preventing the generation of the increase of noises and the saturation of gains. When an optical filter is used at an outgoing end, the quantity of spontaneous emission light of the light amplifier 3 is reduced.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は光通信その他の光信号処理に利用する。[Detailed description of the invention] [Industrial application field] The present invention is utilized for optical communication and other optical signal processing.

特に、半導体レーザ素子を光増幅器として利用する光増
幅装置に関する。In particular, the present invention relates to an optical amplification device that uses a semiconductor laser element as an optical amplifier.

〔従来の技術〕[Conventional technology]

従来から半導体レーザ素子は、発振素子ではなく光増幅
器として利用されている。このような光増幅器として、
両端面に無反射被膜が設けられた半導体レーザ素子を１
個または複数個縦続に配置した進行波形光増幅器が知ら
れている。Conventionally, semiconductor laser devices have been used not as oscillation devices but as optical amplifiers. As such an optical amplifier,
1 semiconductor laser element with anti-reflection coating on both end faces
Traveling wave optical amplifiers in which one or more traveling wave optical amplifiers are arranged in series are known.

第６図は一般的な光増幅器の構成を示す。ここで、この
光増幅器６１の活性層６２の厚さ方向をＸ方向とし、活
性層の幅方向をｙ方向とする。この光増幅器６１を使用
するには、一般に、電界の振動方向をｙ方向とするＴＥ
波をｙ軸およびｙ軸と直交するＺ軸方向に注入する。こ
の場合に、現状では１個の光増幅器で最大２５ｄＢ程度
の利得が得られている。FIG. 6 shows the configuration of a general optical amplifier. Here, the thickness direction of the active layer 62 of this optical amplifier 61 is defined as the X direction, and the width direction of the active layer is defined as the y direction. In order to use this optical amplifier 61, generally, a TE with the vibration direction of the electric field in the y direction is required.
Waves are injected in the y-axis and the Z-axis direction perpendicular to the y-axis. In this case, at present, a maximum gain of about 25 dB can be obtained with one optical amplifier.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

しかし、半導体レーザ素子を光増幅器として使用する場
合には、ＴＭ波に対する利得が小さい欠点がある。ＴＥ
波に比べると、ＴＭ波の利得は３〜８ｄＢ程度小さい。However, when using a semiconductor laser element as an optical amplifier, there is a drawback that the gain for TM waves is small. T.E.
The gain of the TM wave is about 3 to 8 dB smaller than that of the TM wave.

これは、ＴＥモードとＴＭモードとに対する素子の閉じ
込め係数ｒＴＥ、”ＴＭが異なるからである。一般に製
造されている半導体レーザ素子では、ｒ、ゆとｒ、イと
の比ｒ’ｒ＋／ＦＴＥは０．９〜０．７であり、この値
を１にすることは現状では困難である。This is because the confinement coefficient rTE, TM of the device for the TE mode and the TM mode is different. In a commonly manufactured semiconductor laser device, the ratio r'r+/FTE between r, y and r, i is It is 0.9 to 0.7, and it is currently difficult to set this value to 1.

また、無反射被膜が良好でなければ、ＴＭ波に対する利
得は上述の３〜８ｄＢよりさらに小さくなり、利得差が
大きくなる。Moreover, if the anti-reflection coating is not good, the gain for TM waves will be even smaller than the above-mentioned 3 to 8 dB, and the gain difference will become large.

ＴＥ波とＴＭ波とに対する利得差が大きいと、偏光状態
に応じて利得が変化してしまう。このため、単一モード
光ファイバを用いた伝送系のように偏光状態が保持され
ていない系で光増幅器を用いるには、偏波補償回路が必
要となり、送信装置および中継装置が複雑となる欠点が
ある。If the gain difference between the TE wave and the TM wave is large, the gain will change depending on the polarization state. For this reason, when using an optical amplifier in a system where the polarization state is not maintained, such as a transmission system using a single mode optical fiber, a polarization compensation circuit is required, making the transmitter and repeater complicated. There is.

これらの問題については、ＩＥＩＥＢジャーナル・オブ
・クウォンクム・リレクトロニクス第ＱＥ−２３巻第６
号１９８７年６月第１０１１頁ないし第１０１３頁（Ｉ
ＥＥεＪ、Ｏｕａｎｔｕｍ　Ｅｌｅｃｔｒｏｎｉｃｓ　
Ｖｏｌ、ＱＢ−２３，Ｎｏ、６．　Ｊｕｎｅ１９８７、
　ｐｐｌｏｌｌ−１０１３）や、外国通信技術１９８５
年６月第２９頁に詳しく説明されている。These issues are discussed in IEIEB Journal of Quantum Relectronics Volume QE-23, Volume 6.
No. June 1987, pages 1011 to 1013 (I
EEεJ, Ouantum Electronics
Vol, QB-23, No, 6. June1987,
pploll-1013) and Foreign Communication Technology 1985
A detailed explanation is given on page 29 of June 2017.

本発明は、以上の問題点を解決し、偏光状態に依存しな
い光増幅装置を提供することを目的とする。An object of the present invention is to solve the above problems and provide an optical amplification device that does not depend on the polarization state.

〔問題点を解決するための手段〕[Means for solving problems]

本発明の光増幅装置は、同一光路上に縦続に配置された
二つの半導体レーザ素子を備え、この二つの半導体レー
ザ素子は、その活性層の厚さ方向が上記光路上の光の偏
向に対して互いに直交して配置されたことを特徴とする
。The optical amplifying device of the present invention includes two semiconductor laser elements arranged in series on the same optical path, and the thickness direction of the active layer of the two semiconductor laser elements is relative to the polarization of light on the optical path. They are characterized by being arranged orthogonally to each other.

さらに、二つの半導体レーザ素子の間の光路上に、実質
的に偏波依存性のない光アイソレータを備えることが望
ましい。また、光の出射端には光フィルタを設けること
が望ましい。Furthermore, it is desirable to provide an optical isolator with substantially no polarization dependence on the optical path between the two semiconductor laser elements. Further, it is desirable to provide an optical filter at the light output end.

〔作　用〕[For production]

本発明の光増幅装置は、同一の条件で製造された二つの
半導体レーザ素子を利用し、その活性層の厚さ方向が光
路上の光の偏向に対して互いに直交していることから、
偏光によらず一定の利得を得ることができる。The optical amplifying device of the present invention utilizes two semiconductor laser elements manufactured under the same conditions, and the thickness direction of the active layer is orthogonal to the polarization of light on the optical path.
A constant gain can be obtained regardless of polarization.

〔実施例〕〔Example〕

第１図は本発明第一実施例光増幅装置の構成を示す。 FIG. 1 shows the configuration of an optical amplification device according to a first embodiment of the present invention.

この光増幅装置は、両端面に無反射被膜が設けられた半
導体レーザ素子を光増幅器３．６として備え、この二つ
の光増幅器３．６は同一光路上に縦続に配置され、その
活性層４．７の厚さ方向が光路上の光の偏向に対して互
いに直交して配置されている。さらにこの光増幅装置は
、光増幅器３．６の間に集光用のレンズ５を備えている
。This optical amplification device is equipped with a semiconductor laser element provided with an anti-reflection coating on both end faces as an optical amplifier 3.6, and these two optical amplifiers 3.6 are arranged in series on the same optical path, and their active layer 4 The thickness directions of .7 are arranged orthogonal to each other with respect to the polarization of light on the optical path. Furthermore, this optical amplification device includes a condensing lens 5 between the optical amplifiers 3.6.

入射側にはセルフォックレンズ２が設けられた単一モー
ド光ファイバ１が配置され、出射側にはセルフォックレ
ンズ８が設けられた単一モード光ファイバ９が配置され
る。A single mode optical fiber 1 provided with a SELFOC lens 2 is arranged on the input side, and a single mode optical fiber 9 provided with a SELFOC lens 8 is arranged on the output side.

単一モード光ファイバ１を伝搬した光は、セルフォック
レンズ２を介して光増幅器３の活性層４に注入される。Light propagated through the single mode optical fiber 1 is injected into the active layer 4 of the optical amplifier 3 via the SELFOC lens 2.

この注入光は、ＴＥ波およびＴＭ波に対してそれぞれ利
得ＧＴＥＩ　、ＧＴ）ＩＩだけ増幅されて出力される。This injected light is amplified by gains GTEI and GT)II for the TE wave and TM wave, respectively, and output.

この出力光は、レンズ５を経由して光増幅器６の活性層
７に注入される。この注入光は、ＴＥ波およびＴＭ波に
対してそれぞれ利得Ｇ、、、　、Ｇ、、、だけ増幅され
て出力される。This output light is injected into the active layer 7 of the optical amplifier 6 via the lens 5. This injected light is amplified by a gain G, , , G, , respectively for the TE wave and the TM wave and is output.

この出力光は、セルフォックレンズ２を介して単一モー
ド光ファイバ９に結合する。This output light is coupled to a single mode optical fiber 9 via a SELFOC lens 2.

ここで、光増幅器３に注入される光のパワーをＰ　ｌｎ
ｓこの光増幅器３の出力光のパワーをＰ。ｕｔｌ、光増
幅器６の出力光のパワーをＰ。ｕｔ２とする。Here, the power of light injected into the optical amplifier 3 is P ln
sThe power of the output light of this optical amplifier 3 is P. utl, and the power of the output light of the optical amplifier 6 is P. Let it be ut2.

第２図は光増幅器３による利得を説明する図である。こ
こで、従来例で説明したと同様に、活性層４の厚さ方向
をＸ方向とし、活性層の幅方向をｙ方向とし、光の進行
方向を２軸とする。FIG. 2 is a diagram illustrating the gain by the optical amplifier 3. Here, as described in the conventional example, the thickness direction of the active layer 4 is the X direction, the width direction of the active layer is the y direction, and the traveling directions of light are two axes.

一般に光増幅器３に注入される光は、電界成分Ｅ、　、
ＥｙおよびＥ２を用いて、 ｆＥ、＝ａ・０°５（ｃｃ＋ｔ−ｋｚ＋″・）と表すこ
とができる。ここで、ωは光の角振動数であり、ｋは真
空中での伝搬定数であり、δ１、δ２はそれぞれＥ、、
Ｅ、の位相定数である。Generally, the light injected into the optical amplifier 3 has electric field components E, ,
Using Ey and E2, it can be expressed as fE, = a・0°5(cc+t−kz+″・). Here, ω is the angular frequency of light, and k is the propagation constant in vacuum. Yes, δ1 and δ2 are E, respectively.
is the phase constant of E.

ＴＥ波、ＴＭ波に対する利得がそれぞれＧＴＥＩ％Ｇ　
ｔ　）ｌ　Ｉ　　（Ｇ　Ｔ□≠Ｇｙｘ＋　）なる光増幅
器３に（１）式で表される光を注入すると、この光増幅
器３から出力される光は、 （以下本頁余白） ・・・（２） と表される。δ、は光増幅器３内におけるＴＥ波とＴＭ
波との伝搬定数の違いからくる位相の遅れである。The gain for TE wave and TM wave is GTEI%G, respectively.
When the light expressed by equation (1) is injected into the optical amplifier 3 where t )l I (G T□≠Gyx+ ), the light output from the optical amplifier 3 is (hereinafter referred to as the margin of this page)...( 2) It is expressed as. δ is the TE wave and TM in the optical amplifier 3
This is a phase delay caused by the difference in propagation constant from the wave.

さらにこの光を光増幅器６に注入すると、・　・　（３
） となる。これを第３図に示す。Furthermore, when this light is injected into the optical amplifier 6,...
) becomes. This is shown in FIG.

したがって二つの光増幅器３．６による全体的な利得Ｇ
は、 Ｇ＝Ｐｏｕｔ２／Ｐｉ。Therefore, the overall gain G due to the two optical amplifiers 3.6
is, G=Pout2/Pi.

・　（４） となる。ここで、 ＧＴＥ□／　Ｇ　ＴＸ　Ｉ　＝　Ｇ　ＴＥ□／ＧＴＸ□
＝ｂ（定数）・　（５） とすると、（４）式は、 Ｇ　”　ｂ　Ｇ　Ｔ。・ＧＴＭ□　　　　　　　　・（
６）となる。この式は、この光増幅器の利得が、偏光状
態に依存することなく一定であることを示す。・(4) becomes. Here, GTE□/GTX I = GTE□/GTX□
= b (constant)・(5) Then, equation (4) becomes G ” b GT.・GTM□・(
6). This equation shows that the gain of this optical amplifier is constant regardless of the polarization state.

（５）式は、同一条件で製造された二つの半導体レーザ
素子に対して近似的に成立する。また、（３）式の位相
項が等しいことは、二つの光増幅器３．６によりＴＥ波
とＴＭ波との伝搬定数の差が補償されることを示す。Equation (5) approximately holds true for two semiconductor laser devices manufactured under the same conditions. Furthermore, the fact that the phase terms in equation (3) are equal indicates that the difference in propagation constant between the TE wave and the TM wave is compensated by the two optical amplifiers 3.6.

第４図は本発明第二実施例光増幅装置の構成を示す。こ
の実施例では、性能向上のために、二つの光増幅器３．
６の間に偏波依存性のない光アイソレータ１０が挿入さ
れている。また、光増幅器３と光アイソレータ１０との
間にはレンズ５′が配置され、光アイソレータ１０と光
増幅器６との間にはレンズ５″が配置される。これ以外
の構成は第一実施例と同等である。FIG. 4 shows the configuration of an optical amplification device according to a second embodiment of the present invention. In this embodiment, two optical amplifiers 3.
An optical isolator 10 having no polarization dependence is inserted between 6 and 6. Further, a lens 5' is arranged between the optical amplifier 3 and the optical isolator 10, and a lens 5'' is arranged between the optical isolator 10 and the optical amplifier 6. is equivalent to

光アイソレータ１０の効果について説明する。前段の光
増幅器３から出力された光は、後段の光増幅器６に注入
されて増幅される。増幅された光の一部は、無反射被膜
の不完全性のために、後方すなわち前段の増幅器３の方
向にも出力される。また、後段の光増幅器６は、それ自
身が多くの自然放出光を出力している。これらの光が前
段の光増幅器３に戻ると、雑音の増加および利得の飽和
を引き起こす。光アイソレータ１０によりこれを防止す
ることができる。The effects of the optical isolator 10 will be explained. The light output from the optical amplifier 3 at the front stage is injected into the optical amplifier 6 at the rear stage and amplified. A part of the amplified light is also output toward the rear, that is, the direction of the preceding amplifier 3, due to imperfections in the anti-reflection coating. Further, the optical amplifier 6 in the latter stage itself outputs a large amount of spontaneously emitted light. When these lights return to the optical amplifier 3 in the previous stage, they cause an increase in noise and saturation of the gain. This can be prevented by the optical isolator 10.

光アイソレータ１０としては偏波面依存性のないものを
用いる必要がある。このような光アイソレータは、例え
ばトランザクションズ・オブ・ＩＥＣＥ。As the optical isolator 10, it is necessary to use one that has no dependence on the plane of polarization. Such optical isolators are manufactured by Transactions of IECE, for example.

１９７９年７月第６２−Ｃ巻第７号（Ｔｒａｎｓ、　Ｉ
ＥＣＥ、　１９７９／７゜ｖｏｌ、６２−Ｃ，Ｎｏ、７
）　　ｉ：示すｔｔティ６゜第５図は本発明第三実施例
光増幅装置の構成を示す。この実施例では、第二実施例
におけるレンズ５″に代えて、光フィルタ１１と、その
両側に配置されたレンズ１２．１３とを備える。July 1979 Volume 62-C No. 7 (Trans, I
ECE, 1979/7゜vol, 62-C, No. 7
) i: shown tt tee 6° FIG. 5 shows the configuration of an optical amplification device according to a third embodiment of the present invention. In this embodiment, in place of the lens 5'' in the second embodiment, an optical filter 11 and lenses 12 and 13 arranged on both sides thereof are provided.

光フィルタ１１は１ＯｄＢ低下幅がｌｎｍ以下の光フィ
ルタである。また、レンズ１２は、光アイソレータ１０
からの光をコリメートするだめのものであり、レンズ１
３は光フィルタ１１を透過した光を後段の光増幅器６に
集光するためのものである。The optical filter 11 is an optical filter with a 1OdB reduction width of lnm or less. Further, the lens 12 is an optical isolator 10
It is used to collimate the light from lens 1.
Reference numeral 3 is for condensing the light transmitted through the optical filter 11 onto the optical amplifier 6 at the subsequent stage.

光フィルタ１１としては誘電体多層膜フィルタまたはエ
タロン板が適しているが、前者の方が損失が少ない。ま
た、誘電体多層膜フィルタを用いる場合には、光軸方向
に対して５゛程度傾けることにより、反射による特性劣
化を緩和できる。A dielectric multilayer filter or an etalon plate is suitable as the optical filter 11, but the former has less loss. Further, when a dielectric multilayer filter is used, deterioration of characteristics due to reflection can be alleviated by tilting the filter by about 5 degrees with respect to the optical axis direction.

光フィルタ１１を用いることにより、後段の光増幅器６
に注入される前段の光増幅器３の自然放出光量を１０ｄ
Ｂ以上にわたり低減することができる。By using the optical filter 11, the downstream optical amplifier 6
The amount of spontaneous emission light from the front-stage optical amplifier 3 injected into the
It can be reduced by more than B.

これにより、後段の光増幅器６の利得飽和の加速および
雑音増加を防ぐことができる。This can prevent acceleration of gain saturation of the optical amplifier 6 in the subsequent stage and increase in noise.

図示していないが、後段の光増幅器６の出力側にも光フ
ィルタを配置することにより、さらに雑音を低減できる
。Although not shown, noise can be further reduced by arranging an optical filter on the output side of the optical amplifier 6 in the subsequent stage.

以上の実施例では、二つの光増幅器３．６の間で光が直
進し、しかもその偏光の方向が変化しない場合を例に説
明したが、これらの方向が変化しても、その変化の方向
に沿って活性層４．７を互いに直交に配置することによ
り、同様に本発明を実施できる。In the above embodiment, the case where light travels in a straight line between two optical amplifiers 3.6 and the direction of polarization does not change was explained as an example, but even if these directions change, the direction of the change does not change. The invention can likewise be carried out by arranging the active layers 4.7 orthogonally to each other along the lines.

〔発明の効果〕〔Effect of the invention〕

以上説明したように、本発明の光増幅装置は、偏光状態
に依存せずに、注入された光に対して一定の利得を示す
。したがって、偏波面が保存されない伝送系において、
偏光状態に依存せずに一定の増幅を行うことができる。As described above, the optical amplification device of the present invention exhibits a constant gain for injected light, regardless of the polarization state. Therefore, in a transmission system where the plane of polarization is not preserved,
Constant amplification can be performed independent of the polarization state.

本発明は、単一モード光ファイバを用いた伝送装置に利
用して特に効果がある。The present invention is particularly effective when applied to a transmission device using a single mode optical fiber.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明第一実施例光増幅装置の構成を示す図。 第２図は光増幅器による利得を説明する図。 第３図は二つの光増幅器による利得の効果を示す図。 第４図は本発明第二実施例光増幅装置の構成を示す図。 第５図は本発明第三実施例光増幅装置の構成を示す図。 第６図は半導体レーザ素子を用いた一般的な光増幅器の
構成を示す図。 １．９・・・単一モード光ファイバ、２．８・・・セル
フォックレンズ、３．６・・・光増幅器、４．７・・・
活性層、５．５’　、５”、１２．１３・・・レンズ、
１０・・・光アイソレータ、１１・・・光フィルタ。 特許出願人　日本電信電話株式会社 代理人　弁理士　井　出　直　孝 尾−夾扇仲−」 菖　１　口 邦＝　ＧＴＭ＋　Ｅｘ 昂　２　口 二つの九増惺路による利得 革　３　口 ？Ａ　三コ宍ミ１；１タリ 、￥ｉ　５　口FIG. 1 is a diagram showing the configuration of an optical amplification device according to a first embodiment of the present invention. FIG. 2 is a diagram explaining the gain by an optical amplifier. FIG. 3 is a diagram showing the gain effect of two optical amplifiers. FIG. 4 is a diagram showing the configuration of an optical amplification device according to a second embodiment of the present invention. FIG. 5 is a diagram showing the configuration of an optical amplification device according to a third embodiment of the present invention. FIG. 6 is a diagram showing the configuration of a general optical amplifier using a semiconductor laser element. 1.9... Single mode optical fiber, 2.8... Selfoc lens, 3.6... Optical amplifier, 4.7...
Active layer, 5.5', 5'', 12.13...lens,
10... Optical isolator, 11... Optical filter. Patent Applicant Nippon Telegraph and Telephone Corporation Agent Patent Attorney Nao Ide Takao - Kakaogi Naka'' Iris 1 Kuchikuni = GTM + Ex Kou 2 Gains from two Kumasu Souji 3 Kuchi? A Sanko Shishimi 1; 1 tari, ¥i 5 mouths

Claims (3)

【特許請求の範囲】[Claims] （１）両端面に無反射被膜が設けられた半導体レーザ素
子を光増幅器として備えた光増幅装置において、 同一光路上に縦続に配置された二つの半導体レーザ素子
を備え、 この二つの半導体レーザ素子は、その活性層の厚さ方向
が上記光路上の光の偏向に対して互いに直交して配置さ
れた ことを特徴とする光増幅装置。(1) In an optical amplification device that is equipped with a semiconductor laser element having anti-reflection coatings on both end faces as an optical amplifier, it is equipped with two semiconductor laser elements arranged in series on the same optical path, and these two semiconductor laser elements An optical amplifying device characterized in that the thickness directions of the active layers are arranged orthogonal to the polarization of light on the optical path. （２）両端面に無反射被膜が設けられた半導体レーザ素
子を光増幅器として備えた光増幅装置において、 同一光路上に縦続に配置された二つの半導体レーザ素子
を備え、 この二つの半導体レーザ素子は、その活性層の厚さ方向
が上記光路上の光の偏向に対して互いに直交して配置さ
れ、 上記二つの半導体レーザ素子の間の光路上に実質的に偏
波依存性のない光アイソレータを備えたことを特徴とす
る光増幅装置。(2) In an optical amplifying device that is equipped with a semiconductor laser element having anti-reflection coatings on both end faces as an optical amplifier, it is equipped with two semiconductor laser elements arranged in series on the same optical path, and the two semiconductor laser elements is an optical isolator with substantially no polarization dependence on the optical path between the two semiconductor laser elements, the thickness direction of the active layer being arranged orthogonal to the polarization of the light on the optical path. An optical amplification device characterized by comprising: （３）光アイソレータはその出射端に光フィルタを含む
特許請求の範囲第（２）項に記載の光増幅装置。(3) The optical amplification device according to claim (2), wherein the optical isolator includes an optical filter at its output end.
JP62287655A 1987-11-14 1987-11-14 Light amplifier Pending JPH01129483A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62287655A JPH01129483A (en) 1987-11-14 1987-11-14 Light amplifier

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62287655A JPH01129483A (en) 1987-11-14 1987-11-14 Light amplifier

Publications (1)

Publication Number Publication Date
JPH01129483A true JPH01129483A (en) 1989-05-22

Family

ID=17720015

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62287655A Pending JPH01129483A (en) 1987-11-14 1987-11-14 Light amplifier

Country Status (1)

Country Link
JP (1) JPH01129483A (en)

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US6445495B1 (en) 1999-03-22 2002-09-03 Genoa Corporation Tunable-gain lasing semiconductor optical amplifier
WO2003067721A3 (en) * 2002-02-07 2004-03-04 Lambda Physik Ag Solid-state diode pumped laser employing oscillator-amplifier
US6891664B2 (en) 1999-03-22 2005-05-10 Finisar Corporation Multistage tunable gain optical amplifier
US6909536B1 (en) 2001-03-09 2005-06-21 Finisar Corporation Optical receiver including a linear semiconductor optical amplifier
US7065300B1 (en) 2000-12-14 2006-06-20 Finsiar Corporation Optical transmitter including a linear semiconductor optical amplifier
US7110169B1 (en) 2000-12-14 2006-09-19 Finisar Corporation Integrated optical device including a vertical lasing semiconductor optical amplifier
US7113329B2 (en) 2000-12-14 2006-09-26 Finisar Corporation Optical logical circuits based on lasing semiconductor optical amplifiers
US7149236B1 (en) 2000-05-26 2006-12-12 Finisar Corporation Optoelectronic semiconductor device

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6445495B1 (en) 1999-03-22 2002-09-03 Genoa Corporation Tunable-gain lasing semiconductor optical amplifier
US6512629B1 (en) 1999-03-22 2003-01-28 Genoa Corporation Low-noise, high-power optical amplifier
US6704138B2 (en) 1999-03-22 2004-03-09 Finisar Corporation Low-noise, high-power optical amplifier
US6891664B2 (en) 1999-03-22 2005-05-10 Finisar Corporation Multistage tunable gain optical amplifier
WO2001028049A3 (en) * 1999-10-12 2001-11-22 Genoa Corp Low-noise, high-power optical amplifier
US7149236B1 (en) 2000-05-26 2006-12-12 Finisar Corporation Optoelectronic semiconductor device
US7065300B1 (en) 2000-12-14 2006-06-20 Finsiar Corporation Optical transmitter including a linear semiconductor optical amplifier
US7110169B1 (en) 2000-12-14 2006-09-19 Finisar Corporation Integrated optical device including a vertical lasing semiconductor optical amplifier
US7113329B2 (en) 2000-12-14 2006-09-26 Finisar Corporation Optical logical circuits based on lasing semiconductor optical amplifiers
US7126731B1 (en) 2000-12-14 2006-10-24 Finisar Corporation Optical latch based on lasing semiconductor optical amplifiers
US6909536B1 (en) 2001-03-09 2005-06-21 Finisar Corporation Optical receiver including a linear semiconductor optical amplifier
WO2003067721A3 (en) * 2002-02-07 2004-03-04 Lambda Physik Ag Solid-state diode pumped laser employing oscillator-amplifier

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