JPS6243353B2 - - Google Patents
Info
- Publication number
- JPS6243353B2 JPS6243353B2 JP1098381A JP1098381A JPS6243353B2 JP S6243353 B2 JPS6243353 B2 JP S6243353B2 JP 1098381 A JP1098381 A JP 1098381A JP 1098381 A JP1098381 A JP 1098381A JP S6243353 B2 JPS6243353 B2 JP S6243353B2
- Authority
- JP
- Japan
- Prior art keywords
- semiconductor laser
- optical fiber
- electro
- light
- optical
- 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
Links
- 239000004065 semiconductor Substances 0.000 claims description 50
- 239000013307 optical fiber Substances 0.000 claims description 31
- 238000010168 coupling process Methods 0.000 claims description 12
- 238000005859 coupling reaction Methods 0.000 claims description 12
- 230000005684 electric field Effects 0.000 claims description 12
- 230000008878 coupling Effects 0.000 claims description 11
- 230000003287 optical effect Effects 0.000 claims description 11
- 229910013641 LiNbO 3 Inorganic materials 0.000 description 11
- 239000013078 crystal Substances 0.000 description 11
- 230000000694 effects Effects 0.000 description 5
- 238000004891 communication Methods 0.000 description 4
- 230000010355 oscillation Effects 0.000 description 4
- 238000005253 cladding Methods 0.000 description 3
- 239000005083 Zinc sulfide Substances 0.000 description 2
- 230000001427 coherent effect Effects 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910052984 zinc sulfide Inorganic materials 0.000 description 2
- WSMQKESQZFQMFW-UHFFFAOYSA-N 5-methyl-pyrazole-3-carboxylic acid Chemical compound CC1=CC(C(O)=O)=NN1 WSMQKESQZFQMFW-UHFFFAOYSA-N 0.000 description 1
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 1
- 230000005697 Pockels effect Effects 0.000 description 1
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 1
- 229910002113 barium titanate Inorganic materials 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- OXBLHERUFWYNTN-UHFFFAOYSA-M copper(I) chloride Chemical compound [Cu]Cl OXBLHERUFWYNTN-UHFFFAOYSA-M 0.000 description 1
- 239000012792 core layer Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010291 electrical method Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical group [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- DRDVZXDWVBGGMH-UHFFFAOYSA-N zinc;sulfide Chemical compound [S-2].[Zn+2] DRDVZXDWVBGGMH-UHFFFAOYSA-N 0.000 description 1
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
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/106—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity
- H01S3/107—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity using electro-optic devices, e.g. exhibiting Pockels or Kerr effect
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Optics & Photonics (AREA)
- Optical Couplings Of Light Guides (AREA)
- Semiconductor Lasers (AREA)
Description
【発明の詳細な説明】
この発明は光フアイバ通信における半導体レー
ザと光フアイバとを結合するための装置に関する
ものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for coupling a semiconductor laser and an optical fiber in optical fiber communication.
一般に半導体レーザは小型で、低電圧発振が可
能であり、また直接変調ができることなどから、
光通信用光源として発光ダイオードとともに重要
な素子である。 Semiconductor lasers are generally small, capable of low voltage oscillation, and can be directly modulated.
Along with light emitting diodes, it is an important element as a light source for optical communications.
光フアイバはコアと呼ばれる屈折率の高い部分
とクラツドと呼ばれる屈折率の低い部分から構成
されるガラス繊維で、コア層とクラツド層の境界
で光を全反射させながら伝搬させる光の伝送路で
ある。全反射のくり返しにより導波させる光はモ
ードと呼ばれ、コアとクラツドの境界で異る角度
で反射される多数のモードが伝搬する光フアイバ
をマルチモード光フアイバと呼んでいる。 Optical fiber is a glass fiber consisting of a part with a high refractive index called the core and a part with a low refractive index called the cladding.It is a transmission path for light that propagates while totally reflecting the light at the boundary between the core layer and the cladding layer. . Light that is guided through repeated total reflections is called a mode, and an optical fiber in which multiple modes that are reflected at different angles at the boundary between the core and the cladding propagate is called a multimode optical fiber.
光通信を行なう場合に単一モードで発振してい
るレーザ光源（例えば半導体レーザ）からのコヒ
ーレントな光をマルチモード光フアイバを使つて
伝送させるとモード間で位相速度が異るため、光
フアイバの種々の伝搬モード間で干渉が起こり、
光フアイバからの出射光を観察するとスペツクル
と呼ばれる斑点模様が現われる。これによつて生
じる雑音をモーダル雑音と呼んでいる。 When performing optical communication, when coherent light from a laser light source (e.g. a semiconductor laser) oscillating in a single mode is transmitted using a multimode optical fiber, the phase velocity differs between the modes, so the optical fiber Interference occurs between various propagation modes,
When the light emitted from an optical fiber is observed, a speckled pattern appears. The noise caused by this is called modal noise.
このスペツクリング現象は、光フアイバの振動
の光源の波長ゆらぎ（半導体レーザは単一モード
発振でも電流、温度によつて発振波長が変化す
る）によつて空間的、時間的に変化する。従つ
て、特に光フアイバに接続箇所（コネクタやスプ
ライシング接続）があると、接続点でスペツクル
の欠落が生じ、それが時間的に変動するため、ア
ナログ信号を伝送した場合に大巾にＳ／Ｎの劣化
をもたらす。マルチモード光フアイバをコヒーレ
ントな光が伝搬すると、上記スペツクリング現象
は避けられないので、光フアイバ通信に単一モー
ド半導体レーザを使用する場合には、スペツクル
を低減させる対策を講じる必要がある。 This speckling phenomenon changes spatially and temporally due to the wavelength fluctuation of the light source caused by the vibration of the optical fiber (the oscillation wavelength of a semiconductor laser changes depending on the current and temperature even if it oscillates in a single mode). Therefore, especially when an optical fiber has a connection point (connector or splicing connection), speckle loss occurs at the connection point, and this changes over time, resulting in a large S/N ratio when transmitting an analog signal. resulting in deterioration. When coherent light propagates through a multimode optical fiber, the speckle phenomenon described above is unavoidable, so when using a single mode semiconductor laser for optical fiber communication, it is necessary to take measures to reduce speckle.
従来、このスペツクルを低減する方法として、
半導体レーザの信号電流に非常に高い周波数を重
畳し、マルチモード発振させ、スペツクルパター
ンを平滑化する方法が提案されている。 Conventionally, as a method to reduce this speckle,
A method has been proposed in which a very high frequency is superimposed on the signal current of a semiconductor laser to cause multimode oscillation and to smooth the speckle pattern.
この発明は、従来のもののように電気的な方法
によらず、簡単な光学的手段を用いてスペツクル
雑音（モーダル雑音）を低減させることにより、
安価な半導体レーザと光フアイバの結合装置を提
供することを目的としている。 This invention uses simple optical means to reduce speckle noise (modal noise), instead of using electrical methods as in conventional methods.
The purpose of this invention is to provide an inexpensive coupling device for a semiconductor laser and an optical fiber.
以下、この発明の一実施例を図について説明す
る。 An embodiment of the present invention will be described below with reference to the drawings.
第１図において、１は半導体レーザ、２は結合
用レンズ、５はこの半導体レーザ１の一方の光出
力が入射されるように配置された光フアイバ、３
は上記半導体レーザ１の上記光フアイバ５と反対
側に配置された電気光学素子、３ａは電気光学素
子５の両端面に形成された電極、３ｂはリード
線、３ｃは電気光学素子３に高周波電界を印加す
るための高周波電源回路、４は電気光学素子３を
通過してきた光を反射し電気光学素子３およびレ
ンズ２を介して半導体レーザ１に再結合させるた
めの反射鏡である。 In FIG. 1, 1 is a semiconductor laser, 2 is a coupling lens, 5 is an optical fiber arranged so that one optical output of this semiconductor laser 1 is incident, and 3
is an electro-optical element disposed on the opposite side of the optical fiber 5 of the semiconductor laser 1, 3a is an electrode formed on both end surfaces of the electro-optic element 5, 3b is a lead wire, and 3c is a high-frequency electric field applied to the electro-optic element 3. A high frequency power supply circuit 4 is a reflecting mirror for reflecting the light that has passed through the electro-optical element 3 and recombining it to the semiconductor laser 1 via the electro-optical element 3 and the lens 2.
次に動作について説明する。 Next, the operation will be explained.
電気光学結晶に電界をかけると電気光学効果に
より屈折率が変化するが、特にその変化量が電界
に比例するものはポツケルス効果と呼ばれてい
る。 When an electric field is applied to an electro-optic crystal, the refractive index changes due to the electro-optic effect, and the one in which the amount of change is proportional to the electric field is called the Pockels effect.
このような電気光学効果を持つ結晶、例えばニ
オブ酸リチウム（LiNbO3）のｃ軸方向に電界を加
えると、電界方向と、電界方向に垂直な方向の屈
折率が次式のように変化する。 When an electric field is applied in the c-axis direction of a crystal having such an electro-optic effect, such as lithium niobate (LiNbO 3 ), the refractive index in the direction of the electric field and in the direction perpendicular to the direction of the electric field changes as shown in the following equation.
△n1＝１／２ne3r13E3
△n2＝１／２ne3r23E3 (1)
△n3＝１／２ne3r33E3
ここで、neはLiNbO3の異常光線屈折率、ｒは
ポツケルス係数、Ｅは電界をそれぞれ現わす（添
字１、２、３はそれぞれｘ、ｙ、ｚ軸方向を表わ
す）。△n3＞△n1、△n2であるので△n3に着目
し、LiNbO3に印加されている電界に対し、光の
電界の振幅方向が一致するように光を入射させる
と、長さｄのLiNbO3を通過した光は△n3dだけ光
路長が変化することになる。 △n 1 = 1/2ne 3 r 13 E 3 △n 2 = 1/2ne 3 r 23 E 3 (1) △n 3 = 1/2ne 3 r 33 E 3 where ne is the extraordinary ray refraction of LiNbO 3 r represents the Pockels coefficient, and E represents the electric field (subscripts 1, 2, and 3 represent the x-, y-, and z-axis directions, respectively). Since △n 3 >△n 1 and △n 2 , focusing on △n 3 , if light is incident so that the amplitude direction of the electric field of the light matches the electric field applied to LiNbO 3 , the length will be The optical path length of the light passing through LiNbO 3 of d changes by Δn 3 d.
ところで、半導体レーザが外部の反射体によつ
て反射され戻つてきた光を再び半導体レーザの活
性層に再結合させると、自己結合効果と呼ばれる
現象が生じ、本来、単一波長で発振していた半導
体レーザは多数の波長で発振するようになる。こ
のように多数の波長で発振している光源の光をマ
ルチモードフアイバに結合させると、スペツクル
が生じないのでモーダル雑音は低減される。 By the way, when a semiconductor laser recombines the light reflected back by an external reflector into the active layer of the semiconductor laser, a phenomenon called the self-coupling effect occurs, causing the laser to oscillate at a single wavelength. Semiconductor lasers now oscillate at multiple wavelengths. When light from a light source oscillating at multiple wavelengths is coupled to a multimode fiber, modal noise is reduced because no speckle is generated.
しかるにこのように戻り光を半導体レーザに再
結合させる場合においても反射鏡のみを使用した
場合は、半導体レーザ１の信号電流の変化によつ
て光出力が変動し、その結果、戻り光の光パワー
の変動となり、発振モードが不安定になる。 However, even when recombining the returned light to the semiconductor laser in this way, if only a reflector is used, the optical output will fluctuate due to changes in the signal current of the semiconductor laser 1, and as a result, the optical power of the returned light will change. This causes the oscillation mode to become unstable.
そこで、単一波長で発振している半導体レーザ
１の光フアイバ５と反対側への出力光をレンズ２
を介して反射鏡４に結合する際に、レンズ２と反
射鏡４の間に電気光学素子、例えばLiNbO3結晶
３を挿入する。LiNbO3結晶３のｃ軸と垂直な二
面には電極３ａをそれぞれ蒸着し、半導体レーザ
１の接合面をLiNbO3結晶３のｃ軸と平行になる
ように配置する。 Therefore, the output light from the semiconductor laser 1, which is oscillating at a single wavelength, to the side opposite to the optical fiber 5 is sent to the lens 2.
When coupling to the reflecting mirror 4 via the lens 2, an electro-optical element, for example, a LiNbO 3 crystal 3, is inserted between the lens 2 and the reflecting mirror 4. Electrodes 3a are deposited on two surfaces perpendicular to the c-axis of the LiNbO 3 crystal 3, and the junction surface of the semiconductor laser 1 is arranged parallel to the c-axis of the LiNbO 3 crystal 3.
半導体レーザ１の光は一般に接合面に平行な電
界を持つTEモードで発振しており、上記のよう
に配置することによつて屈折率n3の変化△n3によ
る影響を受ける。いま、
△n3d＝λ／４
を満すようにすると、半導体レーザ１からの光は
反射鏡４により、LiNbO3結晶３を２回通り、半
導体レーザ１にその位相がπだけ変化して再結合
される。ここでλは光の波長を表わす。従つて、
LiNbO3結晶３に高周波電源回路３ｃを付加する
と（このピーク値で電界は(2)式を満す）、単一波
長で発振する半導体レーザ１を安定した多数の波
長で発振させることができる。 The light from the semiconductor laser 1 generally oscillates in a TE mode with an electric field parallel to the junction surface, and is affected by the change Δn 3 in the refractive index n 3 by arranging it as described above. Now, if △n 3 d=λ/4 is satisfied, the light from the semiconductor laser 1 passes through the LiNbO 3 crystal 3 twice by the reflecting mirror 4, and the phase changes to the semiconductor laser 1 by π. be recombined. Here, λ represents the wavelength of light. Therefore,
When a high frequency power supply circuit 3c is added to the LiNbO 3 crystal 3 (the electric field satisfies equation (2) at this peak value), the semiconductor laser 1 that oscillates at a single wavelength can be stably oscillated at a large number of wavelengths.
従つて、このようにした上で半導体レーザ１の
第１図右側端からの出力光をレンズ２を介して光
フアイバ５に結合させると、スペツクルが減少
し、モーダル雑音を低減させることができる。こ
の際位相変調のための高周波電源回路３ｃの周波
数は半導体レーザ１の信号の変調周波数よりも高
い周波数とし、受信機においてローパスフイルタ
を通すことにより、この高周波成分を除去してや
ればよい。 Therefore, if the output light from the right end of the semiconductor laser 1 in FIG. 1 is coupled to the optical fiber 5 via the lens 2 in this manner, speckles can be reduced and modal noise can be reduced. At this time, the frequency of the high frequency power supply circuit 3c for phase modulation is set higher than the modulation frequency of the signal of the semiconductor laser 1, and this high frequency component is removed by passing the signal through a low pass filter in the receiver.
例えばLiNbO3結晶の場合633nmの波長の光に
対し、r33は30.8×10-12ｍ／Ｖ、neは2.2であるの
でこれらを式(1)、(2)に代入し、厚みを２mm、印加
電圧を50Vとして計算すると、約3.8cmの長さが
あればよいことになる。850nmの波長の半導体レ
ーザの光に対しても同程度の値である。 For example, in the case of LiNbO 3 crystal, for light with a wavelength of 633 nm, r 33 is 30.8 × 10 -12 m/V and ne is 2.2, so by substituting these into equations (1) and (2), the thickness is 2 mm, If the applied voltage is 50V, the length should be about 3.8cm. The value is about the same for light from a semiconductor laser with a wavelength of 850 nm.
電気光学素子の材料としては、LiNbO3結晶の
他、タンタル酸リチウム（LiTaO3）、チタン酸バ
リウム（BaTiO3）、KDP、ADP、硫化亜鉛
（ZnS）、塩化銅（CuCl）、ガリウム砒素
（GaAs）、さらには透明電圧セラミツクスである
PLZTが利用できる。 Materials for electro-optical elements include LiNbO 3 crystal, lithium tantalate (LiTaO 3 ), barium titanate (BaTiO 3 ), KDP, ADP, zinc sulfide (ZnS), copper chloride (CuCl), and gallium arsenide (GaAs). ), and even transparent voltage ceramics.
PLZT is available.
第２図はこの発明の他の実施例を示すもので、
電気光学結晶３の半導体レーザ１からの光の入射
面と反対側の端面に反射膜６を形成し、装置の簡
素化を図つたものである。 FIG. 2 shows another embodiment of this invention,
A reflective film 6 is formed on the end surface of the electro-optic crystal 3 opposite to the incident surface of the light from the semiconductor laser 1, thereby simplifying the device.
第３図は、この発明のさらに他の実施例を示す
もので、電気光学結晶３と半導体レーザ１の間
に、光の一部を取り出すための半透過鏡７を挿入
し、反射された光を光検出器８に結合させ、半導
体レーザ１の出力をモニタすることによつて光出
力を制御することができるようにしたものであ
る。 FIG. 3 shows still another embodiment of the present invention, in which a semi-transparent mirror 7 is inserted between the electro-optic crystal 3 and the semiconductor laser 1 to take out a part of the light, and the reflected light is is coupled to a photodetector 8, and by monitoring the output of the semiconductor laser 1, the optical output can be controlled.
なお、上記実施例では半導体レーザを光フアイ
バと結合させる場合を示したが、単一波長で発振
している半導体レーザを多数の波長で発振させる
必要がある他の場合にも利用できることは言うま
でもない。 Although the above embodiment shows the case where a semiconductor laser is coupled to an optical fiber, it goes without saying that it can also be used in other cases where a semiconductor laser that oscillates at a single wavelength needs to oscillate at multiple wavelengths. .
また光フアイバ端面からの反射による戻り光を
除去するためには、上記実施例にフアラデー効果
素子と偏光子により構成される光アイソレータを
半導体レーザと光フアイバの間に挿入すればよ
い。 Furthermore, in order to eliminate the return light due to reflection from the end face of the optical fiber, an optical isolator composed of a Faraday effect element and a polarizer may be inserted between the semiconductor laser and the optical fiber in the above embodiment.
以上のように、この発明に係る半導体レーザと
光フアイバの結合装置によれば、半導体レーザと
反射鏡の間に電気光学素子を挿入し、半導体レー
ザの他方からの光をも光フアイバに結合させるよ
うにしたので、簡単な構成により安価にスペツク
ル雑音を低減できる効果がある。 As described above, according to the semiconductor laser and optical fiber coupling device according to the present invention, an electro-optical element is inserted between the semiconductor laser and the reflecting mirror, and light from the other semiconductor laser is also coupled to the optical fiber. This has the effect of reducing speckle noise at low cost with a simple configuration.
第１図はこの発明の一実施例による半導体レー
ザと光フアイバの結合装置を示す概略斜視図、第
２図はこの発明の他の実施例を示す概略斜視図、
第３図はこの発明のさらに他の実施例を示す概略
斜視図である。
１……半導体レーザ、２……レンズ、３……電
気光学素子、３ｃ……高周波電源回路、４……反
射鏡、５……光フアイバ、６……反射膜、７……
半透過鏡、８……光検出器。なお図中、同一符号
は同一又は相当部分を示す。
FIG. 1 is a schematic perspective view showing a semiconductor laser and optical fiber coupling device according to one embodiment of the invention, FIG. 2 is a schematic perspective view showing another embodiment of the invention,
FIG. 3 is a schematic perspective view showing still another embodiment of the invention. DESCRIPTION OF SYMBOLS 1...Semiconductor laser, 2...Lens, 3...Electro-optical element, 3c...High frequency power supply circuit, 4...Reflector, 5...Optical fiber, 6...Reflection film, 7...
Semi-transparent mirror, 8...photodetector. In the figures, the same reference numerals indicate the same or corresponding parts.
Claims (1)
光出力が入射されるよう配置された光フアイバ
と、上記半導体レーザの上記光フアイバと反対側
に配置され上記半導体レーザからの他方の光出力
がレンズを介して入射される電気光学素子と、こ
の電気光学素子に高周波電界を印加するための高
周波電源回路と、上記電気光学素子を通過した光
を反射し該電気光学素子および上記レンズを介し
て上記半導体レーザに再結合させるための反射体
とを備えたことを特徴とする半導体レーザと光フ
アイバの結合装置。 ２ 上記反射体が、上記電気光学素子と別体の反
射鏡であることを特徴とする特許請求の範囲第１
項記載の半導体レーザと光フアイバの結合装置。 ３ 上記反射体が、上記電気光学素子の上記半導
体レーザからの光の入射面と反対側の端面に形成
された反射膜であることを特徴とする特許請求の
範囲第１項記載の半導体レーザと光フアイバの結
合装置。 ４ 上記高周波電源回路の周波数を、上記半導体
レーザの変調周波数よりも高くしたことを特徴と
する特許請求の範囲第１項ないし第３項のいずれ
かに記載の半導体レーザと光フアイバの結合装
置。 ５ 上記電気光学素子と半導体レーザの間に配置
された半透過鏡と、この半透過鏡の反射光を検出
する光検出器とを備えたことを特徴とする特許請
求の範囲第１項ないし第４項のいずれかに記載の
半導体レーザと光フアイバの結合装置。[Scope of Claims] 1. A semiconductor laser, an optical fiber arranged to receive the optical output of one of the semiconductor lasers, and an optical fiber arranged on the opposite side of the semiconductor laser to receive the optical output of the other laser from the semiconductor laser. an electro-optical element into which the light output of is incident through a lens; a high-frequency power supply circuit for applying a high-frequency electric field to the electro-optical element; A device for coupling a semiconductor laser and an optical fiber, comprising a reflector for recoupling the semiconductor laser to the semiconductor laser through a lens. 2. Claim 1, wherein the reflector is a reflecting mirror separate from the electro-optical element.
A device for coupling a semiconductor laser and an optical fiber as described in 2. 3. The semiconductor laser according to claim 1, wherein the reflector is a reflective film formed on an end surface of the electro-optical element opposite to the incident surface of light from the semiconductor laser. Optical fiber coupling device. 4. The semiconductor laser and optical fiber coupling device according to claim 1, wherein the frequency of the high frequency power supply circuit is higher than the modulation frequency of the semiconductor laser. 5. Claims 1 to 5 further include a semi-transmissive mirror disposed between the electro-optical element and the semiconductor laser, and a photodetector for detecting reflected light from the semi-transmissive mirror. 5. A coupling device for a semiconductor laser and an optical fiber according to any one of Item 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1098381A JPS57124490A (en) | 1981-01-26 | 1981-01-26 | Coupler for semiconductor laser and optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1098381A JPS57124490A (en) | 1981-01-26 | 1981-01-26 | Coupler for semiconductor laser and optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57124490A JPS57124490A (en) | 1982-08-03 |
| JPS6243353B2 true JPS6243353B2 (en) | 1987-09-12 |
Family
ID=11765379
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1098381A Granted JPS57124490A (en) | 1981-01-26 | 1981-01-26 | Coupler for semiconductor laser and optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57124490A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62254478A (en) * | 1986-04-28 | 1987-11-06 | Yokogawa Electric Corp | Variable wavelength light source |
| JPH0325987A (en) * | 1989-06-23 | 1991-02-04 | Kokusai Denshin Denwa Co Ltd <Kdd> | Semiconductor laser light source |
| KR100850718B1 (en) * | 2007-01-17 | 2008-08-06 | 삼성전자주식회사 | Speckle reduction laser |
| JP5209067B2 (en) * | 2011-01-26 | 2013-06-12 | 三菱電機株式会社 | Speckle removal light source and illumination device |
-
1981
- 1981-01-26 JP JP1098381A patent/JPS57124490A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57124490A (en) | 1982-08-03 |
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