JPS6257117B2 - - Google Patents
Info
- Publication number
- JPS6257117B2 JPS6257117B2 JP3037881A JP3037881A JPS6257117B2 JP S6257117 B2 JPS6257117 B2 JP S6257117B2 JP 3037881 A JP3037881 A JP 3037881A JP 3037881 A JP3037881 A JP 3037881A JP S6257117 B2 JPS6257117 B2 JP S6257117B2
- Authority
- JP
- Japan
- Prior art keywords
- semiconductor laser
- pulse train
- frequency
- optical pulse
- laser
- 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
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- 239000004065 semiconductor Substances 0.000 claims description 49
- 238000000034 method Methods 0.000 claims description 17
- 230000005284 excitation Effects 0.000 claims description 15
- 230000010355 oscillation Effects 0.000 claims description 5
- 230000003287 optical effect Effects 0.000 description 40
- 238000007796 conventional method Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 4
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical compound CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 description 3
- 230000000903 blocking effect Effects 0.000 description 3
- 125000005842 heteroatom Chemical group 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 239000003990 capacitor Substances 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 229910000980 Aluminium gallium arsenide Inorganic materials 0.000 description 1
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000005468 ion implantation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 210000000056 organ Anatomy 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
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/062—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes
- H01S5/0625—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
Landscapes
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Optics & Photonics (AREA)
- Semiconductor Lasers (AREA)
Description
【発明の詳細な説明】
本発明は、半導体レーザを用い、その半導体レ
ーザより、その半導体レーザより得られるレーザ
光がパルス列にて光強度変調されてなる態様の光
パルス列を発生せしめる光パルス列発生法に関す
る。DETAILED DESCRIPTION OF THE INVENTION The present invention provides an optical pulse train generation method that uses a semiconductor laser and generates an optical pulse train from the semiconductor laser in which the laser light obtained from the semiconductor laser is modulated in optical intensity in a pulse train. Regarding.
斯種光パルス列発生法は、それによつて得られ
る光パルス例を用いて光フアイバの分散特性、光
検波器の応答特性等を測定するに適用し得るもの
であるが、従来の光パルス列発生法として、第１
図に示す如く、一端面にフアブリペローの反射面
１が形成され、他端面に無反射用膜２が附されて
なる半導体レーザ３と、その半導体レーザ３の無
反射用膜２に光学系４を介して対向せる反射鏡５
と、半導体レーザ３の無反射用膜２及び反射鏡５
間に配された、半導体レーザ３の反射面１及び反
射鏡５間の共振器長Ｌに相当する数多くの軸モー
ドを含む態様を以つて半導体レーザ３自体の共振
器長ｌに相当する数多くの軸モード中の１つの軸
モードを選択するエタロン６とを用い、而して半
導体レーザ３に、これにてレーザ発振の得られる
閾値電流値又はその近傍値を有するバイアス電流
ＩBを塞流線輪７を介してバイアス電流源８より
供給せしめ、且共振器長Ｌによつて決まる軸モー
ド間隔に相当する周波数を有する制御電流ＩC
を直流阻止用コンデンサ９を介して制御電流源１
０より供給せしめることにより、半導体レーザ３
の反射面１側より、その半導体レーザ３より得ら
れるレーザ光の上述せる周波数を有するパルス
列にて光強度変調されてなる態様の、第２図に示
す如き光パルス列Ｐを発生せしめるという方法が
提案されている。 This type of optical pulse train generation method can be applied to measuring the dispersion characteristics of an optical fiber, the response characteristics of a photodetector, etc. using the example optical pulses obtained thereby, but the conventional optical pulse train generation method As, the first
As shown in the figure, a semiconductor laser 3 has a Fabry-Perot reflective surface 1 formed on one end face and an anti-reflection film 2 attached to the other end face, and an optical system 4 is attached to the anti-reflection film 2 of the semiconductor laser 3. Reflector 5 facing through
, the anti-reflection film 2 of the semiconductor laser 3 and the reflecting mirror 5
In a mode including a large number of axial modes corresponding to the resonator length L between the reflecting surface 1 of the semiconductor laser 3 and the reflecting mirror 5 arranged in between, a large number of axial modes corresponding to the resonator length l of the semiconductor laser 3 itself are included. Using an etalon 6 that selects one of the axial modes, a bias current I B having a threshold current value or a value close to the threshold current value for laser oscillation is applied to the semiconductor laser 3 as a blockage line. A control current I C is supplied by a bias current source 8 via a ring 7 and has a frequency corresponding to the axial mode spacing determined by the resonator length L.
is connected to the controlled current source 1 via the DC blocking capacitor 9.
By supplying from 0, the semiconductor laser 3
A method has been proposed in which an optical pulse train P as shown in FIG. 2 is generated by modulating the optical intensity of the laser light obtained from the semiconductor laser 3 with a pulse train having the above-mentioned frequency from the reflective surface 1 side of the semiconductor laser 3. has been done.
然し乍ら斯る従来の方法の場合、目的とせる光
パルス列Ｐを発生せしめるにつき、半導体レーザ
３の外、光学系４、反射鏡５及びエタロン６を要
し、この為光パルス列Ｐを発生せしめる為の全体
の装置が大型、複雑化すると共に、半導体レーザ
３及び反射鏡５の相対的位置、及び半導体レーザ
３及び反射鏡５と光学系４との相対的位置の調整
を要する欠点を有していた。 However, in the case of such a conventional method, in addition to the semiconductor laser 3, an optical system 4, a reflecting mirror 5, and an etalon 6 are required to generate the desired optical pulse train P. The overall device is large and complicated, and has the disadvantage that the relative positions of the semiconductor laser 3 and the reflecting mirror 5 and the relative positions of the semiconductor laser 3 and the reflecting mirror 5 and the optical system 4 must be adjusted. .
又第１図にて上述せる従来の方法の場合、半導
体レーザ３の反射鏡５側の端面には無反射用膜２
が附されているとしても、その無反射用膜２でレ
ーザ光の反射が生ずるのは否めなく、この為光パ
ルス列Ｐを発生せしめる為の装置が共振器長Ｌを
有する共振器の外、共振器長ｌを有する共振器及
び共振器長（Ｌ−ｌ）を有する共振器を構成せる
構成を有し、この為光パルス列Ｐが、共振器長ｌ
によつて決まる軸モード間隔に相当する周波数を
有する不要パルス列、共振器長（Ｌ−ｌ）によつ
て決まる軸モード間隔に相当する周波数を有する
不要パルス列等の不要パルス列を伴なつて発生す
るという欠点を有していた。 In addition, in the case of the conventional method described above in FIG.
is attached, it is undeniable that reflection of the laser beam occurs on the anti-reflection film 2, and for this reason, the device for generating the optical pulse train P is not connected to the resonator having the resonator length L. It has a configuration in which a resonator having a cavity length l and a resonator having a cavity length (L-l) are configured, so that the optical pulse train P is
It is said that unnecessary pulse trains are generated, such as an unnecessary pulse train having a frequency corresponding to the axial mode interval determined by , and an unnecessary pulse train having a frequency corresponding to the axial mode interval determined by the resonator length (L-l). It had drawbacks.
更に第１図にて上述せる従来の方法の場合、エ
タロン６により半導体レーザ３自体の共振器長ｌ
に相当する数多くの軸モード中の１つの軸モード
みを選択して目的とせる光パルス列Ｐを発生せし
める様になされているので、半導体レーザ３の全
利得幅を利用して光パルス列Ｐを発生せしめてい
るものではなく、この為光パルス列Ｐがその各パ
ルスをして幅Ｗの狭いものとして発生するのが望
まれるとしても、各パルスをして幅Ｗの広いもの
としてしか発生しないという欠点を有していた。 Furthermore, in the case of the conventional method described above with reference to FIG.
The optical pulse train P is generated by using the entire gain width of the semiconductor laser 3. Therefore, even if it is desired that the optical pulse train P generates each pulse with a narrow width W, the disadvantage is that each pulse can only be generated with a wide width W. It had
依つて本発明は上述せる欠点のない新規な光パ
ルス列発生法を提案せんとするもので、以下詳述
する所より明らかとなるであろう。 The present invention therefore proposes a novel optical pulse train generation method free from the above-mentioned drawbacks, which will become clear from the detailed description below.
本発明者は種々の実験の結果、例えば第３図に
示す如き、例えばＰ型の半導体基板３１上にＰ型
の半導体閉込層３２、Ｎ型又はＰ型の半導体活性
層３３及びＮ型の半導体閉込層３４がそれ等の順
に順次積層されてなる積層体３５を有し、而して
その積層体３５の相対向する端面が夫々フアブリ
ペローの反射面３６及び３７となされ、又積層体
３５の半導体基板３１側の面及び半導体閉込層３
４側の面上に夫々電極３８及び３９が附されてな
るそれ自体は公知の所謂ダブルヘテロ型半導体レ
ーザ構成に於て、そのダブルヘテロ型半導体レー
ザ構成に、それを電極３８上よりみたときダブル
ヘテロ型半導体構成の反射面３６及び３７間の共
振器長Ｄをとる方向に２分する如く、電極３８側
より半導体基板３１内に達する深さの切欠４０が
附され、これにより電極３８が共振器長Ｄをとる
方向に各別に配列せる２つの電極４１及び４２よ
りなるものとなされ、斯くて各別に励起される、
電極４１、積層体３５の電極４１下の領域及び電
極３９による励起領域Ｍ１と電極４２、積層体３
５の電極４２下の領域及び電極３９による励起領
域Ｍ２とを共振器長Ｄをとる方向に配列形成して
なるという構成の半導体レーザＵを用い、而して
その半導体レーザＵの励起領域Ｍ１及びＭ２に半
導体レーザＵにてレーザ発振の得られる閾値電流
値又は近傍値を有するバイアス電流ＩB1及びＩB2
を夫々塞流線輪４３及び４４を介してバイアス電
流源４５及び４６より供給せしめ、又励起領域Ｍ
２に共振器長Ｄによつて決まる軸モード間隔に相
当する周波数′を有する制御電流ＩC′を直流阻
止用コンデンサ４７を介して制御電流源４８より
供給せしめれば、半導体レーザＵの反射面３６及
び３７より、その半導体レーザＵより得られるレ
ーザ光の上述せる軸モード間隔に相当する周波数
′を有するパルス列にて光強度変調されてなる
態様の第４図に示す如き光パルス列P′が発生して
得られること、又斯る光パルス列P′は、上述に於
てその制御電流ＩC′を上述せる軸モード間隔に相
当する周波数′を有するものとしなくても、周
波数′の整数ｍ倍の周波数ｍ′を有するもの、
又は周波数′の整数ｍ分の１倍の周波数1/m
′を有するものとしても得られること、更に上
述せる光パルス列P′を得るにつき図示の如くバイ
アス電流ＩB2の外制御電流ＩC′の供給される励起
領域Ｍ２の共振器長Ｄをとる方向の長さd2がバイ
アス電流ＩB1のみの供給される励起領域Ｍ１のそ
れd1に比し小であるを可とすることを確認するに
到つた。 As a result of various experiments, the present inventor has found that, for example, as shown in FIG. It has a laminate 35 in which semiconductor confinement layers 34 are sequentially laminated in that order, and the opposing end surfaces of the laminate 35 serve as Fabry-Perot reflecting surfaces 36 and 37, respectively, and the laminate 35 The surface of the semiconductor substrate 31 side and the semiconductor confinement layer 3
In the so-called double hetero type semiconductor laser structure, which is known per se and in which electrodes 38 and 39 are attached on the four side surfaces, respectively, the double hetero type semiconductor laser structure has a double hetero type when viewed from above the electrode 38. A notch 40 with a depth reaching into the semiconductor substrate 31 from the electrode 38 side is provided so as to divide the resonator into two in the direction of the resonator length D between the reflecting surfaces 36 and 37 of the hetero-type semiconductor structure, thereby causing the electrode 38 to resonate. It is made up of two electrodes 41 and 42 that are arranged separately in the direction of the organ length D, and are thus excited separately.
The electrode 41, the region under the electrode 41 of the laminate 35, the excitation region M1 by the electrode 39, the electrode 42, the laminate 3
A semiconductor laser U having a configuration in which a region under the electrode 42 of No. 5 and an excitation region M2 formed by the electrode 39 are arranged in the direction of the resonator length D is used. Bias currents I B1 and I B2 having a threshold current value or a value close to the threshold current value that allows laser oscillation to be obtained in the semiconductor laser U in M2.
are supplied from bias current sources 45 and 46 via blocking wires 43 and 44, respectively, and the excitation region M
2, if a control current I C ' having a frequency ' corresponding to the axial mode spacing determined by the resonator length D is supplied from the control current source 48 via the DC blocking capacitor 47, the reflection surface of the semiconductor laser U 36 and 37 generate a light pulse train P' as shown in FIG. 4 in which the light intensity is modulated with a pulse train having a frequency 'corresponding to the above-mentioned axial mode spacing of the laser light obtained from the semiconductor laser U. In addition, such an optical pulse train P' can be obtained by multiplying the frequency by an integer m times the frequency', even if the control current I C ' has a frequency 'corresponding to the axial mode spacing'. with a frequency m' of
Or the frequency 1/m, which is one times the integer m of the frequency '
Furthermore, in order to obtain the optical pulse train P' mentioned above, as shown in the figure, the direction in which the resonator length D of the excitation region M2 to which the control current I C ' is supplied outside the bias current I B2 is taken. It has been confirmed that the length d 2 can be smaller than the length d 1 of the excitation region M1 to which only the bias current I B1 is supplied.
又本発明者は、第３図にて上述せる半導体レー
ザＵでなくても、要は各別に励起される少くとも
第１及び第２の励起領域（第３図の場合の励起領
域Ｍ１及びＭ２に対応する）を共振器長（第３図
の場合の共振器長Ｄに対応する）をとる方向に配
列してなる構成を有する半導体レーザでありさえ
すれば、その半導体レーザを用い、その第１及び
第２の励起領域にその半導体レーザにてレーザ発
振の得られる閾値電流又はその近傍値を有するバ
イアス電流（第３図の場合のバイアス電流ＩB1及
びＩB2に対応す）を供給せしめ、又第２の励起領
域（第３図の場合の励起領域Ｍ２に対応する）に
共振器長によつて決まる軸モード間隔に相当する
周波数（第３図の場合の周波数′）又はその整
数倍若しくは整数分の１倍（第３図の場合の周波
数ｍ′若しくは1/m′に対応する）を有する制
御電流（第３図の場合の制御電流ＩC′に対応す
る）を供給せしめれば、その半導体レーザよりそ
の半導体レーザより得られるレーザ光の上述せる
軸モード間隔に相当する周波数（第３図の場合の
周波数′に対応する）を有するパルス列にて光
強度変調されてなる態様の光パルス列（第４図に
示す光パルス列P′に対応する）を発生して得るこ
とが出来ることを確認するに到つた。 Furthermore, the present inventor has proposed that, even if the semiconductor laser U described above in FIG. As long as the semiconductor laser has a configuration in which the laser beams (corresponding to the resonator length D in the case of FIG. supplying the first and second excitation regions with a bias current (corresponding to bias currents I B1 and I B2 in the case of FIG. 3) having a threshold current or a value close to the threshold current at which laser oscillation is obtained in the semiconductor laser; Further, in the second excitation region (corresponding to excitation region M2 in the case of FIG. 3), a frequency corresponding to the axial mode spacing determined by the resonator length (frequency' in the case of FIG. 3), or an integral multiple thereof, or If a control current (corresponding to the control current I C ' in the case of FIG. 3) having a frequency m' or 1/m' multiplied by an integer (corresponding to the frequency m' or 1/m' in the case of Figure 3) is supplied, An optical pulse train in which the intensity of the laser light obtained from the semiconductor laser is modulated by a pulse train having a frequency corresponding to the above-mentioned axial mode spacing (corresponding to frequency' in the case of FIG. 3). (corresponding to the optical pulse train P' shown in FIG. 4) can be generated and obtained.
依つて此処に特許請求の範囲所載の本発明によ
る光パルス列発生法を提案するに到つたもので、
その１つの実施例は、第３図にて上述せる如く、
第３図にて上述せる共振器長Ｄを有する半導体レ
ーザＵを用い、而してその励起領域Ｍ１及びＭ２
に第３図にて上述せると同様に半導体レーザＵに
てレーザ発振の得られる閾値電流値又はその近傍
値を有するバイアス電流ＩB1及びＩB2を夫々供給
せしめ、又励起領域Ｍ２に第３図にて上述せると
同様に共振器長Ｄによつて決まる軸モード間隔に
相当する周波数′又はその整数倍若しくは整数
分の１倍の周波数ｍ′又は1/m′を有する制御
電流ＩC′を供給せしめることにより、半導体レー
ザＵよりその半導体レーザＵより得られるレーザ
光の上述せる軸モード間隔に相当する周波数′
を有するパルス列にて光強度変調されてなる態様
の第４図に示す如き光パルス列P′を発生せしめる
というものである。 Therefore, we have come to propose the optical pulse train generation method according to the present invention as set forth in the claims,
One embodiment is as described above in FIG.
In FIG. 3, a semiconductor laser U having the cavity length D described above is used, and its excitation regions M1 and M2 are
3, bias currents I B1 and I B2 each having a threshold current value or a value close to the threshold current value at which laser oscillation can be obtained in the semiconductor laser U are supplied to the excitation region M2 in the same manner as described above in FIG. 3. As mentioned above, the control current I C ' has a frequency 'corresponding to the axial mode spacing determined by the resonator length D, or a frequency m' or 1/m' that is an integral multiple or a fraction thereof. By supplying the semiconductor laser U, the frequency ' corresponding to the above-mentioned axial mode spacing of the laser light obtained from the semiconductor laser U is
The optical pulse train P' shown in FIG. 4 is generated by modulating the optical intensity with a pulse train having the following values.
以上にて本発明による光パルス列発生法の実施
例が明らかとなつたが、斯る方法によれば、目的
とせる光パルス列P′を発生せしめるにつき、半導
体レーザＵ以外に、第１図にて上述せる従来の方
法の場合の如くに光学系、反対鏡及びエタロンを
用いるを要せず、従つて光パルス列P′を発生せし
める為の全体の装置が第１図にて上述せる従来の
方法の場合に比し格段的に簡易、小型化されると
共に、第１図にて上述せる従来の方法の場合の如
くに位置調整を要しないという大なる特徴を有す
るものである。 The embodiment of the optical pulse train generation method according to the present invention has been clarified above, but according to this method, in order to generate the desired optical pulse train P', in addition to the semiconductor laser U, as shown in FIG. It is not necessary to use an optical system, a counter mirror and an etalon as in the conventional method described above, and therefore the entire apparatus for generating the optical pulse train P' is shown in FIG. This method has the great feature that it is much simpler and more compact than the conventional method, and that it does not require position adjustment unlike the conventional method described above with reference to FIG.
又第３図に示す本発明による光パルス列発生法
の場合、光パルス列P′を発生せしめる為の装置
が、半導体レーザＵによる、共振器長Ｄを有する
共振器構成のみしか有しないので、光パルス列
P′が第１図にて上述せる従来の方法の場合の如く
に不要パルス列を伴なつて発生するということが
ないという大なる特徴を有するものである。 In addition, in the case of the optical pulse train generation method according to the present invention shown in FIG. 3, since the device for generating the optical pulse train P' only has a resonator configuration with a resonator length D using the semiconductor laser U, the optical pulse train
This method has the great feature that P' is not generated accompanied by an unnecessary pulse train as is the case with the conventional method described above with reference to FIG.
更に第３図に示す本発明による光パルス列発生
法の場合、光パルス列P′を発生せしめる為の装置
が半導体レーザＵによる共振器構成のみしか有し
ないので、光パルス列P′を半導体レーザＵの全利
得を利用して発生せしめているものであり、従つ
て光パルス列P′を、その各パルスをして幅Ｗの、
第１図にて上述せる従来の方法にて得られる光パ
ルス列Ｐの各パルスの幅Ｗに比し格段的に狭いも
のとして得られるという特徴を有するものであ
る。因みに、半導体レーザＵをGaAs／AlGaAs
系を用いた共振器長Ｄが４mmであるものとし、こ
のとき共振器長Ｄによつて決まる軸モード間隔に
相当する周波数′が8.2GHzであることにより、
8.2GHzの周波数を有する制御電流ＩC′を半導体
レーザＵの励起領域Ｍ２に供給した所、光パルス
列P′がその各パルスの幅Ｗ（半値全幅）をして
1psであるものとして得られた。従つて本発明に
よる方法は、これを各パルスをして幅Ｗの狭い光
パルス列を用いることが望まれる光フアイバの分
散特性、光検出器の応答特性等を測定するに適用
して好適なものである。 Furthermore, in the case of the optical pulse train generation method according to the present invention shown in FIG. It is generated using gain, and therefore the optical pulse train P' is made up of a width W of each pulse.
This method is characterized in that the width W of each pulse of the optical pulse train P obtained by the conventional method described above in FIG. 1 is much narrower than the width W of each pulse. By the way, the semiconductor laser U is GaAs/AlGaAs
Assume that the resonator length D using the system is 4 mm, and the frequency ' corresponding to the axial mode spacing determined by the resonator length D is 8.2 GHz.
When a control current I C ' having a frequency of 8.2 GHz is supplied to the excitation region M2 of the semiconductor laser U, the optical pulse train P' has a width W (full width at half maximum) of each pulse.
Obtained as being 1 ps. Therefore, the method according to the present invention is suitable for use in measuring dispersion characteristics of optical fibers, response characteristics of photodetectors, etc., where it is desired to use a narrow optical pulse train with a width W of each pulse. It is.
尚上述に於ては本発明の一例を示したに留ま
り、半導体レーザとして、第３図にて上述せる半
導体レーザに於てその切欠４０を例えばイオン打
込により絶縁化されてなる絶縁領域、不純物のイ
オン打込乃至拡散により形成された半導体基板３
１とは逆の導電型を有する半導体領域に置換せし
めてなることを除いては第３図の半導体レーザＵ
と同様の半導体レーザを用いることも出来、その
他本発明の精神を脱することなしに種々の変型変
更をなし得るであろう。 The above description merely shows an example of the present invention, and the notch 40 of the semiconductor laser shown in FIG. A semiconductor substrate 3 formed by ion implantation or diffusion of
The semiconductor laser U in FIG. 3 except that it is replaced with a semiconductor region having a conductivity type opposite to that of 1
A semiconductor laser similar to the above may be used, and various other modifications may be made without departing from the spirit of the invention.
第１図は従来の光パルス列発生法を示す略線
図、第２図はそれによつて得られる光パルス列を
示す図、第３図は本発明による光パルス列発生法
の一例を示す略線図、第４図はそれによつて得ら
れる光パルス列を示す図である。
図中Ｕは半導体レーザ、Ｍ１及びＭ２は励起領
域、４５及び４６はバイアス電流源、４８は制御
電流源を夫々示す。
FIG. 1 is a schematic diagram showing a conventional optical pulse train generation method, FIG. 2 is a diagram showing an optical pulse train obtained thereby, and FIG. 3 is a schematic diagram showing an example of an optical pulse train generation method according to the present invention. FIG. 4 is a diagram showing the optical pulse train obtained thereby. In the figure, U indicates a semiconductor laser, M1 and M2 excitation regions, 45 and 46 bias current sources, and 48 a control current source, respectively.
Claims (1)
起領域を共振器長をとる方向に配列形成してなる
半導体レーザを用い、該半導体レーザの第１及び
第２の励起領域に当該半導体レーザにてレーザ発
振の得られる閾値電流値又はその近傍値を有する
バイアス電流を供給せしめ、上記第２の励起領域
に上記共振器長によつて決まる軸モード間隔に相
当する周波数又はその整数倍若しくは整数分の１
倍の周波数を有する制御電流を供給せしめること
により、上記半導体レーザより当該半導体レーザ
より得られるレーザ光の上記軸モード間隔に相当
する周波数を有するパルス列にて光強度変調され
てなる態様の光パルス列を発生せしめる事を特徴
とする光パルス列発生法。1. Using a semiconductor laser in which at least first and second excitation regions that are excited separately are arranged and formed in the direction of the resonator length, the first and second excitation regions of the semiconductor laser are A bias current having a threshold current value for laser oscillation or a value close to it is supplied to the second excitation region, or a frequency corresponding to the axial mode spacing determined by the resonator length, or an integral multiple thereof or an integer number. one part
By supplying a control current having twice the frequency, a light pulse train is generated from the semiconductor laser in which the light intensity is modulated by a pulse train having a frequency corresponding to the axial mode interval of the laser light obtained from the semiconductor laser. A light pulse train generation method characterized by the generation of light pulses.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3037881A JPS57145385A (en) | 1981-03-03 | 1981-03-03 | Method for generating light pulse train |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3037881A JPS57145385A (en) | 1981-03-03 | 1981-03-03 | Method for generating light pulse train |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57145385A JPS57145385A (en) | 1982-09-08 |
| JPS6257117B2 true JPS6257117B2 (en) | 1987-11-30 |
Family
ID=12302212
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3037881A Granted JPS57145385A (en) | 1981-03-03 | 1981-03-03 | Method for generating light pulse train |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57145385A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59165480A (en) * | 1983-03-10 | 1984-09-18 | Nec Corp | Semiconductor light emitting element |
| JPS6032381A (en) * | 1983-08-01 | 1985-02-19 | Matsushita Electric Ind Co Ltd | Surface light emitting semiconductor laser device |
| JPH067610B2 (en) * | 1984-03-05 | 1994-01-26 | 日本電信電話株式会社 | Semiconductor laser device |
| JPS61271887A (en) * | 1985-05-27 | 1986-12-02 | Nippon Telegr & Teleph Corp <Ntt> | Semiconductor laser |
| KR950002137A (en) * | 1993-06-30 | 1995-01-04 | 세끼사와 다까시 | Modulator direct-distribution feedback laser diode module and device using the same |
-
1981
- 1981-03-03 JP JP3037881A patent/JPS57145385A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57145385A (en) | 1982-09-08 |
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