JPH069280B2 - Semiconductor laser device - Google Patents

Semiconductor laser device

Info

Publication number
JPH069280B2
JPH069280B2 JP63153241A JP15324188A JPH069280B2 JP H069280 B2 JPH069280 B2 JP H069280B2 JP 63153241 A JP63153241 A JP 63153241A JP 15324188 A JP15324188 A JP 15324188A JP H069280 B2 JPH069280 B2 JP H069280B2
Authority
JP
Japan
Prior art keywords
region
layer
conductivity type
optical waveguide
light
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 - Fee Related
Application number
JP63153241A
Other languages
Japanese (ja)
Other versions
JPH01319986A (en
Inventor
正人 石野
洋一 佐々井
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP63153241A priority Critical patent/JPH069280B2/en
Priority to US07/296,020 priority patent/US4961198A/en
Publication of JPH01319986A publication Critical patent/JPH01319986A/en
Publication of JPH069280B2 publication Critical patent/JPH069280B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related 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
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/11—Comprising a photonic bandgap structure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
    • 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
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/026—Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers
    • H01S5/0265—Intensity modulators
    • 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
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • 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
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/1021—Coupled cavities
    • 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
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/12—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
    • 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
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/12—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
    • H01S5/125—Distributed Bragg reflector [DBR] lasers
    • 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
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • H01S5/34—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
    • H01S5/343—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser
    • H01S5/3434—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser with a well layer comprising at least both As and P as V-compounds
    • 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
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • 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
    • H01S2304/00—Special growth methods for semiconductor lasers
    • H01S2304/06—LPE
    • 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
    • H01S5/20—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers
    • H01S5/2054—Methods of obtaining the confinement
    • H01S5/2077—Methods of obtaining the confinement using lateral bandgap control during growth, e.g. selective growth, mask induced
    • 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
    • H01S5/20—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers
    • H01S5/22—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers having a ridge or stripe structure
    • H01S5/223—Buried stripe structure
    • H01S5/2232—Buried stripe structure with inner confining structure between the active layer and the lower electrode
    • H01S5/2234—Buried stripe structure with inner confining structure between the active layer and the lower electrode having a structured substrate surface
    • H01S5/2235—Buried stripe structure with inner confining structure between the active layer and the lower electrode having a structured substrate surface with a protrusion
    • 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
    • H01S5/20—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers
    • H01S5/22—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers having a ridge or stripe structure
    • H01S5/227—Buried mesa structure ; Striped active layer
    • H01S5/2272—Buried mesa structure ; Striped active layer grown by a mask induced selective growth
    • 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
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • H01S5/34—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
    • H01S5/343—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser
    • H01S5/34306—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser emitting light at a wavelength longer than 1000nm, e.g. InP based 1300 and 1500nm lasers
    • 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
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/4025—Array arrangements, e.g. constituted by discrete laser diodes or laser bar
    • H01S5/4031—Edge-emitting structures
    • 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
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/4025—Array arrangements, e.g. constituted by discrete laser diodes or laser bar
    • H01S5/4087—Array arrangements, e.g. constituted by discrete laser diodes or laser bar emitting more than one wavelength

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Nanotechnology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biophysics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Semiconductor Lasers (AREA)

Description

【発明の詳細な説明】 産業上の利用分野 本発明は長距離大容量光伝送、コヒーレント通信等に必
要な光源である高性能半導体レーザ装置に関する。TECHNICAL FIELD The present invention relates to a high-performance semiconductor laser device which is a light source required for long-distance large-capacity optical transmission, coherent communication, and the like.

従来の技術 近年、光通信の長距離大容量化に伴い、光源として高速
でかつ変調によるチャーピングの少ない高性能半導体レ
ーザの開発が望まれている。さらに将来の光通信技術と
いわれているコヒーレント通信においては非常に狭いス
ペクト幅のレーザが必要となる。分布帰還型レーザ（Ｄ
ＦＢ−ＬＤ）は高速変調時においても安定な単一軸モー
ド発振が得られ、従来のファブリーペロ型レーザに比べ
て伝送特性に大きな改善を果たしてきた。しかしながら
ＤＦＢ−ＬＤにおいてもチャーピング抑制、スペクトル
幅は十分でない。この問題を解決する方法として光導波
路（外部変調器）をモノリシックに一体化したＤＦＢ−
ＬＤが注目されている。第３図はこの一体化素子の光軸
方向の断面基本構造を示すものである。これはｎ−Ｉｎ
Ｐ基板１上の第１の領域２１にＩｎＧａＡｓＰ活性層１
３、ｐ−ＩｎＧａＡｓＰ光導波層３、ｐ−ＩｎＰクラッ
ド層４、ｐ−ＩｎＧａＡｓＰコンタクト層５、ｐ型電極
６を含み、第２の領域２２において光導波層８、ｐ−Ｉ
ｎＰクラッド層９、ｐ−ＩｎＧａＡｓＰコンタクト層１
０、ｐ型電極１１を含む構造である。ここで活性（発
光）域である第１の領域２１における光導波層３上には
レーザ発振に必要な回折格子７が、ＩｎＰ基板１の裏面
にはｎ型電極１２が形成されている。また光変調域であ
る第２の領域２２の光導波層８は第１の領域２１からの
出射光１０と同一光軸上に位置し、両領域は分離領域１
３により電気的に分離されている。第１の領域２１から
の出射光１０は第２の領域２２の光導波層を低損失で伝
搬される。ここで発光域２１の電極６−１２間に順方向
電流を流してレーザ発振をさせた状態で、光変調域２２
の電極１１−１２間に逆バイアス印加することフランツ
ーケルディシュ効果により導波光の変調を行なうことが
きる。また光導波層８が多重量子井戸（ＭＱＷ）構造で
あれば量子閉じ込めシュタルク効果が利用できより大き
い光変調効果を得る事ができる。このような外部変調器
一体化ＬＤではＬＤの直接変調時に問題となる注入キャ
リヤ変化による変調光のチャーピングやスペクトル幅の
拡がりは大きく抑圧できる。2. Description of the Related Art In recent years, with the increase in long-distance and large-capacity optical communication, there has been a demand for development of a high-performance semiconductor laser as a light source that is fast and has little chirping due to modulation. Furthermore, in coherent communication, which is said to be an optical communication technology in the future, a laser with a very narrow spectrum width is required. Distributed feedback laser (D
The FB-LD) can obtain stable single axis mode oscillation even at high speed modulation, and has achieved a great improvement in transmission characteristics as compared with the conventional Fabry-Perot laser. However, even in DFB-LD, the chirping suppression and the spectrum width are not sufficient. As a method of solving this problem, a DFB-in which an optical waveguide (external modulator) is monolithically integrated
LD is drawing attention. FIG. 3 shows a basic sectional structure of the integrated element in the optical axis direction. This is n-In
InGaAsP active layer 1 is formed in the first region 21 on P substrate 1.
3, p-InGaAsP optical waveguide layer 3, p-InP cladding layer 4, p-InGaAsP contact layer 5, p-type electrode 6, and in the second region 22, the optical waveguide layer 8, p-I.
nP clad layer 9, p-InGaAsP contact layer 1
It is a structure including 0 and p-type electrode 11. Here, the diffraction grating 7 necessary for laser oscillation is formed on the optical waveguide layer 3 in the first region 21 which is the active (light emitting) region, and the n-type electrode 12 is formed on the back surface of the InP substrate 1. The optical waveguide layer 8 in the second region 22 which is the optical modulation region is located on the same optical axis as the light 10 emitted from the first region 21, and both regions are separated regions 1
It is electrically separated by 3. The emitted light 10 from the first region 21 propagates in the optical waveguide layer of the second region 22 with low loss. Here, in a state where a forward current is passed between the electrodes 6-12 of the light emitting region 21 to cause laser oscillation, the light modulating region 22
By applying a reverse bias between the electrodes 11 and 12, the guided light can be modulated by the Franz-Keldysh effect. If the optical waveguide layer 8 has a multiple quantum well (MQW) structure, the quantum confined Stark effect can be used and a larger optical modulation effect can be obtained. In such an LD with an integrated external modulator, it is possible to greatly suppress the chirping of the modulated light and the spread of the spectrum width due to the change of the injected carrier, which is a problem when the LD is directly modulated.

しかしながらこのような素子は、活性域の活性層３と光
変調域の光導波層は異なるバンドギャプを有するエピタ
キシャル層である必要があり、通常は複数回のエピタキ
シャル成長を含む非常に複雑な工程によってのみ作成で
きるものである。このような複雑な工程は素子作製の歩
留まりのみならず素子特性に悪影響を及ぼす。特に複数
回のエピタキシャル成長によって生じる境界部での異常
成長や再成長層の軸ずれ等により発光域と光変調域間の
光波の結合効率は小さく、光出力の低下等の問題があ
る。However, in such a device, the active layer 3 in the active region and the optical waveguide layer in the optical modulation region need to be epitaxial layers having different band gaps, and usually, it is produced only by a very complicated process including multiple epitaxial growths. It is possible. Such a complicated process adversely affects not only the yield of device fabrication but also device characteristics. In particular, due to abnormal growth at the boundary portion caused by a plurality of times of epitaxial growth, axial misalignment of the regrown layer, and the like, the coupling efficiency of light waves between the light emission region and the light modulation region is small, and there is a problem such as a decrease in light output.

一方、低チャーピング・狭スペクトル幅のＬＤとしては
他に分布ブラッグ反射型レーザ（ＤＢＲ−ＬＤ）があ
る。第４図はその基本構造の光軸方向の断面図である。
その層構造は第３図の外部変調型ＤＦＢ−ＬＤとほとん
ど同一であるが、この素子においては回折格子７は光帰
還域（ＤＢＲ域）２３の光導波層８上に形成されてい
る。このＬＤは活性域２１に電流注入することにより、
光導波域２２の回折格子で決まる波長で発振が得られ
る。従って変調による注入キャリヤの変化によるチャー
ピングは小さく、またＤＢＲ域２３からの光のフィード
バックによる狭スペクトルを得ることができる。またこ
の素子の場合、ＤＢＲ域２３に別個の電極１１を形成し
電流注入等の手段で光導波層８の屈折率を変化させるこ
とにより波長を可変にすることができる。On the other hand, as another LD having a low chirping and a narrow spectrum width, there is a distributed Bragg reflection laser (DBR-LD). FIG. 4 is a sectional view of the basic structure in the optical axis direction.
The layer structure is almost the same as the external modulation type DFB-LD in FIG. 3, but in this element, the diffraction grating 7 is formed on the optical waveguide layer 8 in the optical feedback region (DBR region) 23. By injecting current into the active region 21, this LD
Oscillation can be obtained at a wavelength determined by the diffraction grating of the optical waveguide region 22. Therefore, the chirping due to the change of the injected carrier due to the modulation is small, and a narrow spectrum due to the feedback of the light from the DBR region 23 can be obtained. In the case of this element, the wavelength can be made variable by forming a separate electrode 11 in the DBR region 23 and changing the refractive index of the optical waveguide layer 8 by means of current injection or the like.

しかしながら、ＤＢＲ−ＬＤの場合も外部変調型ＤＦＢ
−ＬＤの場合と同じく複数回路のエピ成長を含む複雑な
作製プロセスを必要とし、各領域間での十分な光波の結
合効率が得られず発振しきい値の上昇等の特性の劣化が
問題となる。However, even in the case of DBR-LD, external modulation type DFB
As in the case of LD, a complicated fabrication process including epi growth of a plurality of circuits is required, sufficient light wave coupling efficiency between regions cannot be obtained, and deterioration of characteristics such as increase of oscillation threshold is a problem. Become.

発明が解決しようとする課題 以上、従来の技術における半導体レーザにおいては、工
程の複雑さや境界部の不連続性等により十分な特性が得
られなかった。Problems to be Solved by the Invention As described above, in the conventional semiconductor laser, sufficient characteristics cannot be obtained due to the complexity of the process, the discontinuity of the boundary portion, and the like.

課題を解決するための手段 本発明は上述の問題点を克服すべく、第１の導電型の同
一半導体基板上に活性層、回折格子、第２の導電型のエ
ピタキシャル層、第２の導電型の第１の電極を含む第１
の領域と前期第１の領域から発した光に対する光導波層
を含む第２の領域を有し、前記第１の領域において活性
層と前記第２の領域の光導波層が同一成長層の多重量子
井戸層で構成され、かつ第１の領域における前記量子井
戸層の井戸層厚が第２の領域における井戸層厚よりも大
きいことを特徴とする半導体レーザ装置であり、また第
１の導電型の同一半導体基板上に活性層と第２の導電型
のエピタキシャル層と第２の導電型の第１の電極を含む
第１の領域と前記第１の領域から発した光に対する光導
波層と回折格子を含む第２の領域を有し、前記第１の領
域における活性層と前記第２の領域の光導波層が同一成
長層の多重量子井戸層で構成され、かつ第１の領域にお
ける前記量子井戸層の井戸層厚が第２の領域における井
戸層厚よりも大きいことを特徴とする半導体レーザ装置
である。Means for Solving the Problems In order to overcome the above-mentioned problems, the present invention provides an active layer, a diffraction grating, a second conductivity type epitaxial layer, and a second conductivity type on the same first conductivity type semiconductor substrate. First including a first electrode of
And a second region including an optical waveguide layer for the light emitted from the first region, and the active layer in the first region and the optical waveguide layer in the second region are the same growth layer. A semiconductor laser device comprising a quantum well layer, wherein the well layer thickness of the quantum well layer in the first region is larger than the well layer thickness in the second region. A first region including an active layer, an epitaxial layer of a second conductivity type, and a first electrode of a second conductivity type on the same semiconductor substrate, and an optical waveguide layer for diffracting light emitted from the first region and diffraction. A second region including a lattice, the active layer in the first region and the optical waveguide layer in the second region are composed of multiple quantum well layers of the same growth layer, and the quantum in the first region is formed. The well layer thickness of the well layer is larger than the well layer thickness of the second region. Is a semiconductor laser device according to claim.

作用 上述の手段により、非常に安易な作製プロセスで高性能
の外部変調型ＤＦＢレーザおよびＤＢＲレーザを得るこ
とができる。Action By the means described above, a high performance external modulation type DFB laser and DBR laser can be obtained by a very easy manufacturing process.

実施例 以下、本発明の実施例をInGaAsP/InP系材料を用いた場
合について述べる。Example An example of the present invention will be described below using an InGaAsP / InP-based material.

第１図は本発明による第１の実施例としてのＤＦＢレー
ザの光軸方向の断面基板構造図を示す。この素子は発光
機能と波長選択機能を有する活性領域２１と光変調機能
を有する光変調領域２２で構成される。ここで、１はｎ
−ＩｎＰ基板、２はＩｎＧａＡｓＰ多重量子井戸（ＭＱ
Ｗ）層、３はＩｎＧａＡｓＰ光導波層、４はｐ−ＩｎＰ
クラッド層、５はｐ−ＩｎＧａＡｓＰコンタクト層、６
および１１はｐ型電極、および１２はｎ型電極である。
ここで活性領域２１内の光導波層上にはピッチ４０００
Åの回折格子が形成されている。また活性領域２１と光
変調領域２２間はプロトン注入層１３により電気的に分
離されている。ＭＱＷ層２は活性領域２１においては井
戸層厚（Ｌｚ）が２００Å、障壁層厚２００Åであるの
に対し、光変調領域２２においては井戸層厚（Ｌｚ）が
１００Å障壁層厚１００Åと領域２１と２３で膜厚が異
なる。量子シフト量の差異によりＭＱＷ層のバンドギャ
ップ波長は領域２１で1.29μｍであるのに対し、領域２
２においては1.27μｍと各領域で異なっている。このよ
うなウェハー内で同一成長層の膜厚を変化させることは
領域間で幅の異なるメサストライプの形成された基板上
に液相エピタキシャル成長を行なうことにより可能で、
ストライプ幅によって制御性良く井戸層厚を変化させる
ことができる。この場合ＩｎＰ基板１の光変調域２２に
のみ光軸方向に沿って幅８μｍのメサストライプを形成
して成長を行なった。FIG. 1 shows a cross-sectional substrate structure diagram in the optical axis direction of a DFB laser as a first embodiment according to the present invention. This element is composed of an active region 21 having a light emitting function and a wavelength selecting function and a light modulating region 22 having a light modulating function. Where 1 is n
-InP substrate, 2 is InGaAsP multiple quantum well (MQ
W) layer, 3 is an InGaAsP optical waveguide layer, 4 is p-InP
Cladding layer, 5 is a p-InGaAsP contact layer, 6
11 and 12 are p-type electrodes, and 12 are n-type electrodes.
Here, a pitch of 4000 is provided on the optical waveguide layer in the active region 21.
Å Diffraction grating is formed. The active region 21 and the light modulation region 22 are electrically separated by the proton injection layer 13. The MQW layer 2 has a well layer thickness (Lz) of 200 Å and a barrier layer thickness of 200 Å in the active region 21, whereas the well layer thickness (Lz) of the optical modulation region 22 is 100 Å barrier layer thickness of 100 Å. 23, the film thickness is different. Due to the difference in the quantum shift amount, the bandgap wavelength of the MQW layer is 1.29 μm in the region 21, whereas in the region 2
2 is 1.27 μm, which is different in each region. It is possible to change the film thickness of the same growth layer in such a wafer by performing liquid phase epitaxial growth on a substrate on which mesa stripes having different widths between regions are formed.
The well layer thickness can be changed with good controllability by the stripe width. In this case, a mesa stripe having a width of 8 μm was formed along the optical axis direction only in the light modulation region 22 of the InP substrate 1 for growth.

ここで領域１の電極６−１２間に順方向直流電流を印加
すると成長１．３０μｍのレーザー発振が得られる。光
変調領域２２内のＭＱＷ光導波層２においてはこのレー
ザー光はほとんど吸収されず１cm-1以下の低損失で導波
できる。なぜならＭＱＷ構造においては吸収端はバルク
構造に比べ急峻であり、導波光がバンドギャップ波長よ
り３０ｎｍも長波側に位置すれば吸収できる損失はほと
んどないからである。Here, when a forward direct current is applied between the electrodes 6-12 in the region 1, laser oscillation with a growth of 1.30 μm is obtained. In the MQW optical waveguide layer 2 in the optical modulation region 22, this laser light is hardly absorbed and can be guided with a low loss of 1 cm -1 or less. This is because in the MQW structure, the absorption edge is steeper than in the bulk structure, and there is almost no loss that can be absorbed if the guided light is located on the long-wave side 30 nm from the bandgap wavelength.

一方、光変調領域２２の電極１１−１２間に逆バイアス
を印加することにより、光変調を行なうことができる。
ＭＱＷ層においては量子閉じ込めシュタルク効果等によ
り通常のバルクよりも大きい電解印加光吸収効果を有
し、光変調領域長を２００μｍとして１Ｖの電圧印加で
１００％変調を行なうことができる。また活性層と光導
波層が同一ＭＱＷ層２構成されているので結合部でのレ
ーザー光の散乱や軸ずれがなく９０％以上の高い結合効
率が得られるので、一体化による光出力の低下はほとん
どない。またこの素子においては活性領域と光変調領域
が分離されているので直接変調の場合に問題となる変調
時の注入キャリヤ変化によるチャーピングやスペクトル
幅り拡がりはほとんどなく、高速変調によって高品質の
レーザー光を得ることができる。さらに本構造は基本的
に一回のエピタキシャル成長という非常に簡単なプロセ
スで作製でき高い歩留まりが期待でる。On the other hand, light modulation can be performed by applying a reverse bias between the electrodes 11-12 of the light modulation region 22.
The MQW layer has a larger electrolytic absorption light absorption effect than a normal bulk due to the quantum confined Stark effect and the like, and 100% modulation can be performed by applying a voltage of 1 V with an optical modulation region length of 200 μm. In addition, since the active layer and the optical waveguide layer are formed of the same MQW layer 2, there is no scattering of laser light at the coupling part and there is no axial misalignment, and a high coupling efficiency of 90% or more can be obtained. rare. In addition, since the active region and the light modulation region are separated in this element, there is almost no chirping or spectrum broadening due to changes in injected carriers during modulation, which is a problem in direct modulation. You can get the light. Furthermore, this structure can be manufactured basically by a very simple process of one-time epitaxial growth, and high yield is expected.

次に本発明の第２の実施例としてのＤＢＲレーザについ
て述べる。第２図はこの素子の光軸方向の基本断面構成
図である。この素子は活性域２１と帰還域２３で構成さ
れる。層構造および電極構造は第１図におけるＤＦＢレ
ーザと同一であるが、この素子においては回折格子は帰
還域２２の光導波層上に形成されている。またこの場合
もＭＱＷ層２は活性領域２１において井戸層厚（Ｌｚ）
が２００Å、障壁層厚２００Åであるのに対し、光変調
領域２２においては井戸層厚（Ｌｚ）が１００Å障壁層
厚１００Åと領域２１と２３で膜厚が異なり、光帰還域
において低損失で光結合効率の光導波路が得られる。Next, a DBR laser as a second embodiment of the present invention will be described. FIG. 2 is a basic cross-sectional configuration diagram in the optical axis direction of this element. This element comprises an active area 21 and a return area 23. The layer structure and the electrode structure are the same as those of the DFB laser in FIG. 1, but in this element, the diffraction grating is formed on the optical waveguide layer of the feedback region 22. Also in this case, the MQW layer 2 has a well layer thickness (Lz) in the active region 21.
Is 200 Å and the barrier layer thickness is 200 Å, whereas in the light modulation region 22, the well layer thickness (Lz) is 100 Å barrier layer thickness 100 Å and the regions 21 and 23 have different film thicknesses, and light loss is low in the optical feedback region. An optical waveguide having a coupling efficiency can be obtained.

ここで活性域２１の電極６−１２間に順方向電流を印加
することにより、光帰還域２３の回折格子で決まる波長
レーザ発振が得られる。光波の結合効率および導波損失
の改善により光の帰還量が増大し１５ｍＡ以下のしきい
値で発振が得られているまたこの素子においては発振ス
ペクトルは基本的に不活性な光帰還域によって決まるの
で活性域での直接変調によっても低チャーピング・狭ス
ペクトル特性が得られている。さらにこのＤＢＲレーザ
ーの光帰還域２２の電極１１−１２間に電流注入もしく
は電界印加によって光導波路の屈折率を変化させること
により、光出力の大きな変化なく最大３０ｎｍの広範囲
にわたって連続的に発振波長を変化させることができ
る。Here, by applying a forward current between the electrodes 6-12 of the active region 21, wavelength laser oscillation determined by the diffraction grating of the optical feedback region 23 can be obtained. Due to the improvement of light wave coupling efficiency and waveguide loss, the amount of light feedback increases and oscillation is obtained at a threshold value of 15 mA or less. In this device, the oscillation spectrum is basically determined by the inactive optical feedback region. Therefore, low chirping and narrow spectrum characteristics are obtained even by direct modulation in the active region. Furthermore, by changing the refractive index of the optical waveguide by injecting a current or applying an electric field between the electrodes 11-12 of the optical feedback region 22 of this DBR laser, the oscillation wavelength can be continuously changed over a wide range up to 30 nm without a large change in the optical output. Can be changed.

発明の効果 以上、本発明は第１の導電型の同一半導体基板上に活性
層、回折格子、第２の導電型のエピタキシャル層、第２
の導電型の第１の電極を含む第１の領域と前記第１の領
域から発した光に対する光導波を含む第２の領域を有
し、前記第１の領域において活性層と前記第２の領域の
光導波層が同一成長層の多重量子井戸層で構成され、か
つ第１の領域における前記量子井戸層の井戸層厚が第２
の領域における井戸層厚よりも大きいことを特徴とする
という構造により、非常に簡単な構造プロセス良好な発
振特性・変調特性を有する分布帰還型レーザを高歩留ま
りで提供できるものである。As described above, according to the present invention, the active layer, the diffraction grating, the second conductivity type epitaxial layer, and the second conductivity type are formed on the same semiconductor substrate of the first conductivity type.
A first region including a first electrode of conductivity type and a second region including optical waveguide for light emitted from the first region, the active layer and the second region in the first region. The optical waveguide layer in the region is composed of multiple quantum well layers of the same growth layer, and the well layer thickness of the quantum well layer in the first region is the second
The structure which is characterized in that it is thicker than the well layer thickness in the region (2) makes it possible to provide a distributed feedback laser having a very simple structural process and good oscillation characteristics and modulation characteristics at a high yield.

さらに本発明はまた第１の導電型の同一半導体基板上に
活性層と第２の導電型のエピタキシャル層と第２の導電
型の第１の電極を含む第１の領域と前記第１の領域から
発した光に対する光導波層と回折格子を含む第２の領域
を有し、前記第１の領域における活性層と前記第２の領
域の光導波層が同一成長層の多重量子井戸層で構成さ
れ、かつ第１の領域における前記量子井戸層の井戸層厚
が第２の領域における井戸層厚よりも大きいことを特徴
とする構造より、非常に簡単な構造プロセスで良好な発
振特性・変調特性を有する分布ブラック反射型レーザを
歩留まりで提供できるものである。Furthermore, the present invention also provides a first region including an active layer, a second conductivity type epitaxial layer, and a second conductivity type first electrode on the same semiconductor substrate of the first conductivity type, and the first region. Having a second region including an optical waveguide layer and a diffraction grating for the light emitted from the light source, and the active layer in the first region and the optical waveguide layer in the second region are multi-quantum well layers of the same growth layer. In addition, the quantum well layer in the first region has a larger well layer thickness than the well region in the second region. It is possible to provide a distributed black reflection type laser having the following in a yield.

このように本発明による半導体レーザは長距離・大容量
光通信およびコヒーレント光通信用光源としてその実用
価値は大きい。As described above, the semiconductor laser according to the present invention has great practical value as a light source for long-distance, large-capacity optical communication and coherent optical communication.

尚、本発明における使用材料、製造法はこれに限定され
るものではない。The materials used and the manufacturing method in the present invention are not limited to these.

【図面の簡単な説明】[Brief description of drawings]

第１図は本発明の第１の実施例によるＤＦＢ−ＬＤの断
面基本構造図、第２図は本発明の第２の実施例によるＤ
ＢＲ−ＬＤの断面基本構造図、第３図は実施例における
外部変調型ＤＦＢ−ＬＤの断面基本構造図、第４図は従
来例におけるＤＢＲ−ＬＤの断面基本構造図である。 １・・・ＩｎＰ基板、２・・・ＭＱＷ層、７・・・回折
格子、２１・・・活性領域、２２・・・光変調領域、２
３・・・光帰還域。FIG. 1 is a sectional basic structural view of a DFB-LD according to the first embodiment of the present invention, and FIG. 2 is a D according to the second embodiment of the present invention.
FIG. 3 is a cross-sectional basic structure diagram of the BR-LD, FIG. 3 is a cross-sectional basic structure diagram of the external modulation type DFB-LD in the embodiment, and FIG. 4 is a cross-sectional basic structure diagram of the conventional example DBR-LD. 1 ... InP substrate, 2 ... MQW layer, 7 ... Diffraction grating, 21 ... Active region, 22 ... Light modulation region, 2
3 ... Optical return area.

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】第１の導電型の同一半導体基板上に活性
層、回折格子、第２の導電型のエピタキシャル層、第２
の導電型の第１の電極を含む第１の領域と前記第１の領
域から発した光に対する光導波層を含む第２の領域を有
し、前記第１の領域において活性層と前記第２の領域の
光導波層が同一成長層の多重量子井戸層で構成され、か
つ第１の領域における前記量子井戸層の井戸厚が第２の
領域における井戸層厚より大きいことを特徴とする半導
体レーザ装置。1. An active layer, a diffraction grating, a second conductivity type epitaxial layer, and a second conductivity type on the same semiconductor substrate of the first conductivity type.
A first region including a first electrode of conductivity type and a second region including an optical waveguide layer for light emitted from the first region, the active layer and the second region in the first region. 2. A semiconductor laser characterized in that the optical waveguide layer in the region 2 is composed of multiple quantum well layers of the same growth layer, and the well thickness of the quantum well layer in the first region is larger than the well layer thickness in the second region. apparatus. 【請求項２】第１の導電型の同一半導体基板上に活性層
と第２の導電型のエピタキシャル層と第２の導電型の第
１の電極を含む第１の領域と前記第１の領域から発した
光に対する光導波層と回折格子を含む第２の領域を有
し、前記第１の領域における活性層と前記第２の領域の
光導波層が同一成長層の多重量子井戸層で構成され、か
つ第１の領域における前記量子井戸層の井戸層厚が第２
の領域における井戸層厚よりも大きいことを特徴とする
半導体レーザ装置。2. A first region including an active layer, an epitaxial layer of a second conductivity type, and a first electrode of a second conductivity type and the first region on the same semiconductor substrate of the first conductivity type. Having a second region including an optical waveguide layer and a diffraction grating for the light emitted from the light source, and the active layer in the first region and the optical waveguide layer in the second region are multi-quantum well layers of the same growth layer. And the well layer thickness of the quantum well layer in the first region is the second
The semiconductor laser device is characterized in that it is thicker than the well layer thickness in the region. 【請求項３】第２の領域において、第２の導電型の第２
の電極を有することを特徴とする特許請求の範囲第１項
又は第２項記載の半導体レーザ装置。3. A second conductivity type second area in the second area.
The semiconductor laser device according to claim 1 or 2, wherein the semiconductor laser device has the electrode of. 【請求項４】第１，第２の領域の境界域に電気的分離機
能を有する第３の領域を有することを特徴とする特許請
求の範囲第１項又は第２項記載の半導体レーザ装置。4. The semiconductor laser device according to claim 1, further comprising a third region having an electrical isolation function in a boundary region between the first and second regions.
JP63153241A 1988-01-14 1988-06-21 Semiconductor laser device Expired - Fee Related JPH069280B2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP63153241A JPH069280B2 (en) 1988-06-21 1988-06-21 Semiconductor laser device
US07/296,020 US4961198A (en) 1988-01-14 1989-01-12 Semiconductor device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63153241A JPH069280B2 (en) 1988-06-21 1988-06-21 Semiconductor laser device

Related Child Applications (1)

Application Number Title Priority Date Filing Date
JP20455596A Division JP2776381B2 (en) 1996-08-02 1996-08-02 Semiconductor laser device

Publications (2)

Publication Number Publication Date
JPH01319986A JPH01319986A (en) 1989-12-26
JPH069280B2 true JPH069280B2 (en) 1994-02-02

Family

ID=15558144

Family Applications (1)

Application Number Title Priority Date Filing Date
JP63153241A Expired - Fee Related JPH069280B2 (en) 1988-01-14 1988-06-21 Semiconductor laser device

Country Status (1)

Country Link
JP (1) JPH069280B2 (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2836822B2 (en) * 1988-06-23 1998-12-14 日本電信電話株式会社 Method for manufacturing waveguide type semiconductor optical device
JP2771276B2 (en) * 1989-09-01 1998-07-02 日本電気株式会社 Semiconductor optical integrated device and manufacturing method thereof
JPH03284891A (en) * 1990-03-30 1991-12-16 Fujitsu Ltd Optical semiconductor element
JPH0750815B2 (en) * 1990-08-24 1995-05-31 日本電気株式会社 Method for manufacturing semiconductor optical integrated device
DE69115596T2 (en) * 1990-08-24 1996-09-19 Nippon Electric Co Method of manufacturing an optical semiconductor device
EP0641049B1 (en) * 1993-08-31 1998-10-28 Fujitsu Limited An optical semiconductor device and a method of manufacturing the same
US5548607A (en) * 1994-06-08 1996-08-20 Lucent Technologies, Inc. Article comprising an integrated laser/modulator combination
US6151351A (en) * 1994-09-28 2000-11-21 Matsushita Electric Industrial Co., Ltd. Distributed feedback semiconductor laser and method for producing the same
US5974070A (en) * 1997-11-17 1999-10-26 3M Innovative Properties Company II-VI laser diode with facet degradation reduction structure
KR100541913B1 (en) 2003-05-02 2006-01-10 한국전자통신연구원 Sampled-Grating Distributed Feedback Wavelength-Tunable Semiconductor Laser Integrated with Sampled-Grating Distributed Bragg Reflector
JP2006066586A (en) * 2004-08-26 2006-03-09 Oki Electric Ind Co Ltd Mode-locked laser diode and method of controlling wavelength thereof

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60192379A (en) * 1984-03-12 1985-09-30 Mitsubishi Electric Corp Semiconductor laser device
JPH0732279B2 (en) * 1985-01-22 1995-04-10 日本電信電話株式会社 Semiconductor light emitting element
JPS6215875A (en) * 1985-07-12 1987-01-24 Matsushita Electric Ind Co Ltd Semiconductor device and manufacture thereof
JPH0671115B2 (en) * 1985-08-09 1994-09-07 オムロン株式会社 Quantum well semiconductor laser
JPS6364384A (en) * 1986-09-05 1988-03-22 Hitachi Ltd Optical semiconductor integrated device

Also Published As

Publication number Publication date
JPH01319986A (en) 1989-12-26

Similar Documents

Publication Publication Date Title
US4873691A (en) Wavelength-tunable semiconductor laser
US4045749A (en) Corrugation coupled twin guide laser
JPH07326820A (en) Variable wavelength semiconductor laser device
EP0706243A2 (en) Distributed feedback semiconductor laser and method for producing the same
JPH0770791B2 (en) Semiconductor laser and manufacturing method thereof
JPH0256837B2 (en)
JPH0632332B2 (en) Semiconductor laser device
US4811352A (en) Semiconductor integrated light emitting device
US5703974A (en) Semiconductor photonic integrated circuit and fabrication process therefor
JP2746326B2 (en) Semiconductor optical device
CA2139140C (en) A method for fabricating a semiconductor photonic integrated circuit
JPH069280B2 (en) Semiconductor laser device
US5912475A (en) Optical semiconductor device with InP
JPH0732279B2 (en) Semiconductor light emitting element
US5519721A (en) Multi-quantum well (MQW) structure laser diode/modulator integrated light source
JP4411938B2 (en) Modulator integrated semiconductor laser, optical modulation system, and optical modulation method
JP2957240B2 (en) Tunable semiconductor laser
JPH08274404A (en) Multi-quantum well laser diode
US6643309B1 (en) Semiconductor laser device
US11189991B2 (en) Semiconductor optical element and semiconductor optical device comprising the same
JPH0716079B2 (en) Semiconductor laser device
JP2776381B2 (en) Semiconductor laser device
US6734464B2 (en) Hetero-junction laser diode
CN112350148A (en) Semiconductor optical element and semiconductor optical device including the same
JPS6046087A (en) Distributed bragg reflection type semiconductor laser

Legal Events

Date Code Title Description
LAPS Cancellation because of no payment of annual fees