JPH0770789B2 - Distributed feedback semiconductor laser and manufacturing method thereof - Google Patents
Distributed feedback semiconductor laser and manufacturing method thereofInfo
- Publication number
- JPH0770789B2 JPH0770789B2 JP4292851A JP29285192A JPH0770789B2 JP H0770789 B2 JPH0770789 B2 JP H0770789B2 JP 4292851 A JP4292851 A JP 4292851A JP 29285192 A JP29285192 A JP 29285192A JP H0770789 B2 JPH0770789 B2 JP H0770789B2
- Authority
- JP
- Japan
- Prior art keywords
- layer
- resonator
- semiconductor laser
- guide layer
- distributed feedback
- 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
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
- H01S5/20—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
Description
【０００１】[0001]
【産業上の利用分野】本発明は光通信用のや光情報処理
用の半導体レーザに関し、特に低歪特性を持つ分布帰還
化半導体レーザおよびその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser for optical communication and optical information processing, and more particularly to a distributed feedback semiconductor laser having a low distortion characteristic and a manufacturing method thereof.
【０００２】[0002]
【従来の技術】ＣＡＴＶ等のサブキャリア多重光伝送な
どに用いられるアナログ光変調用光源には、低歪特性の
分布帰還型半導体レーザが要求される。分布帰還型半導
体レーザの相互変調歪はレーザの電流−光出力特性の線
形性に大きく関係している。従来用いられてきた分布帰
還型半導体レーザでは共振器方向の電界強度の不均一度
が大きいことにより電流−光出力特性の線形性が悪く、
このためにアナログ変調時に良好な歪特性が得られなか
った。2. Description of the Related Art A distributed feedback semiconductor laser having a low distortion characteristic is required for an analog light modulation light source used for subcarrier multiplex optical transmission such as CATV. The intermodulation distortion of the distributed feedback semiconductor laser is largely related to the linearity of the current-optical output characteristic of the laser. In the conventional distributed feedback semiconductor laser, the non-uniformity of the electric field strength in the cavity direction is large, so the linearity of the current-optical output characteristic is poor,
Therefore, good distortion characteristics could not be obtained during analog modulation.
【０００３】ここで従来の分布帰還型半導体レーザ（Ｄ
ＦＢレーザ）について簡単に説明する。従来のＤＦＢレ
ーザはディジタル変調を目的にしたものがほとんどであ
る。また単一軸モード発振させるために、端面にコーテ
ィングを施し、両端面の反射率を非対称にしたり、ある
いは回折格子の途中に位相シフト領域を設けた位相シフ
トＤＦＢレーザが開発されている。Here, a conventional distributed feedback semiconductor laser (D
The FB laser) will be briefly described. Most conventional DFB lasers are intended for digital modulation. Further, in order to oscillate in a single axis mode, a phase shift DFB laser has been developed in which coating is applied to the end faces to make the reflectance on both end faces asymmetrical, or a phase shift region is provided in the middle of the diffraction grating.
【０００４】しかしこのようなＤＦＢレーザにおいても
キャリア分布が不均一なため電流−光出力特性の線形性
は悪かった。例えば位相シフト型ＤＦＢレーザでは位相
シフト領域に電界が集中するため、そこでキャリア分布
のホールバーニングがおこり、電流に対してスーパーリ
ニアな光出力特性となる場合が多かった。However, even in such a DFB laser, the linearity of the current-optical output characteristic is poor because the carrier distribution is non-uniform. For example, in a phase shift type DFB laser, an electric field is concentrated in a phase shift region, so that hole burning of carrier distribution occurs in many cases, resulting in a super linear optical output characteristic with respect to current.
【０００５】この対策として、回折格子の溝の深さや
形、あるいは幅等を共振器方向（光が伝播する方向）に
変化させたものが提案された。例えば、特開平２−９０
６８８号公報、特開平２−１７２２８９号公報、特開平
３−１１０８８５号公報、特開平２−２００８７号公
報、特開平２−２８１６８１号公報等がある。As a countermeasure against this, it has been proposed to change the depth, shape, width or the like of the groove of the diffraction grating in the resonator direction (direction in which light propagates). For example, Japanese Patent Laid-Open No. 2-90
No. 688, Japanese Patent Application Laid-Open No. 2-172289, Japanese Patent Application Laid-Open No. 3-110885, Japanese Patent Application Laid-Open No. 2-20087, Japanese Patent Application Laid-Open No. 2-281681, and the like.
【０００６】[0006]
【発明が解決しようとする課題】従来の非対称コーティ
ングのＤＦＢレーザや位相シフトＤＦＢレーザでは共振
器内の軸方向の電界分布が不均一であり、電流−光出力
の直線性が悪く、アナログを光通信用として用いること
はできなかった。In conventional DFB lasers with asymmetric coating and phase shift DFB lasers, the electric field distribution in the axial direction in the resonator is non-uniform, and the linearity of the current-optical output is poor, and the analog optical It could not be used for communication.
【０００７】アナログ光通信用のＤＦＢレーザには優れ
た低歪特性が求められている。特にＣＡＴＶ用ＤＦＢレ
ーザでは４２チャンネルのサブキャリア多重伝送におい
てＣＳＯ≦−６０ｄＢｃ，ＣＴＢ≦−６５ｄＢｃという
厳しい低歪特性を満足しなければならない。A DFB laser for analog optical communication is required to have excellent low distortion characteristics. In particular, the DFB laser for CATV must satisfy the severe low distortion characteristics of CSO ≦ −60 dBc and CTB ≦ −65 dBc in 42-channel subcarrier multiplex transmission.
【０００８】本発明の目的は安定した単一軸モード発振
と、電流−光出力特性の直線性の良い低歪特性とを兼ね
備えたアナログ通信用ＤＦＢレーザ及び歩留りに優れた
レーザの製造方法を提供することにある。An object of the present invention is to provide a DFB laser for analog communication which has stable single-axis mode oscillation and low distortion characteristics with good linearity of current-optical output characteristics, and a method of manufacturing a laser with excellent yield. Especially.
【０００９】[0009]
【課題を解決するための手段】本発明は、少なくとも光
ガイド層、活性層、グレーティングを有し、前記光ガイ
ド層のバンドギャップ波長が、共振器方向で中央部分か
ら共振器端面に近づくにつれて長波長となっていること
を特徴とする分布帰還型半導体レーザである。The present invention has at least an optical guide layer, an active layer, and a grating, and the bandgap wavelength of the optical guide layer becomes longer as it approaches the resonator end face from the central portion in the resonator direction. The distributed feedback semiconductor laser is characterized by having a wavelength.
【００１０】本発明の製造方法は、グレーティングを有
する半導体表面上に、ストライプ状の開口部を有し、全
体の幅が共振器の両端部分で広く、中央部分で狭いパタ
ーンの絶縁膜を形成する工程と、気相成長法により前記
ストライプ状の開口部に光ガイド層を選択成長する工程
と、前記絶縁膜を除去し、活性層、クラッド層を含む半
導体層を成長する工程と、少なくとも１つのｐ型電極と
ｎ型電極をそれぞれ形成する工程とを有することを特徴
とする。According to the manufacturing method of the present invention, an insulating film having a stripe-shaped opening is formed on the surface of a semiconductor having a grating, and the entire width is wide at both end portions of the resonator and narrow at the central portion. At least one of a step, a step of selectively growing an optical guide layer in the stripe-shaped opening by a vapor phase growth method, a step of removing the insulating film and growing a semiconductor layer including an active layer and a clad layer; and a step of forming a p-type electrode and an n-type electrode, respectively.
【００１１】[0011]
【作用】図１を用いて本発明の原理について説明する。
図１（ａ）は本発明の分布帰還型半導体レーザの共振器
方向に沿った断面模式図であり、回折格子４の上に光ガ
イド層２と活性層３が形成されている。図１（ｂ）は本
発明の特徴である、光ガイド層２の共振器方向の組成分
布を示すものであり、組成をバンドギャップ波長λｇで
示した図である。共振器の中央部分でバンドギャップ波
長が短波長、端面で長波長となるよう設計されている。The principle of the present invention will be described with reference to FIG.
FIG. 1A is a schematic sectional view of the distributed feedback semiconductor laser of the present invention taken along the cavity direction, in which an optical guide layer 2 and an active layer 3 are formed on a diffraction grating 4. FIG. 1B shows the composition distribution in the cavity direction of the optical guide layer 2, which is a feature of the present invention, and is a diagram showing the composition by the bandgap wavelength λg. It is designed so that the bandgap wavelength is short in the central part of the resonator and long in the end face.
【００１２】図２は本発明を説明する図で均一な回折格
子を有し、両端面の反射率を非対称とした構造の従来の
ＤＦＢレーザと比較した図である。図２（ａ）は光ガイ
ド層の組成の共振器方向の分布を示す図であり、従来は
均一分布であったが、本発明では中央部分でバンドギャ
ップ波長が短波長となるように設定している。この構造
では図２（ｂ）に示すように本発明では、共振器中央部
分でグレーティングの結合係数κが小さく、共振器端面
で大となる。従来構造ではκは共振器内で一定であっ
た。FIG. 2 is a diagram for explaining the present invention and is a diagram for comparison with a conventional DFB laser having a uniform diffraction grating and a structure in which the reflectances of both end faces are asymmetric. FIG. 2 (a) is a diagram showing the distribution of the composition of the optical guide layer in the cavity direction, which was conventionally uniform, but in the present invention, the band gap wavelength is set to be a short wavelength in the central portion. ing. With this structure, as shown in FIG. 2B, in the present invention, the coupling coefficient κ of the grating is small in the central part of the resonator and large at the end face of the resonator. In the conventional structure, κ was constant in the resonator.
【００１３】図２（ｃ）は共振器内部の光強度（Ｅ）分
布を示す図であり、従来構造では非対称な端面反射率に
より、光強度分布は不均一でありそのため図２（ｄ）に
示すように半導体レーザの電流−光出力特性の直線性が
悪かった。このためアナログ変調時の歪の原因となって
いる。FIG. 2 (c) is a diagram showing the light intensity (E) distribution inside the resonator. In the conventional structure, the light intensity distribution is non-uniform due to the asymmetric end face reflectance, and therefore FIG. 2 (d) is shown. As shown, the linearity of the current-light output characteristics of the semiconductor laser was poor. Therefore, this is a cause of distortion during analog modulation.
【００１４】本発明では光強度分布は均一なので、図２
（ｄ）のように電流−光出力の良好な直線性が得られ
る。In the present invention, the light intensity distribution is uniform, so that FIG.
Good linearity of current-light output can be obtained as shown in (d).
【００１５】次に本発明の構造を作製するための方法に
ついて図３を用いて説明する。まずＳｉＯ2 をマスクと
して用いる選択成長についてＩｎＧａＡｓＰ系を例にし
て説明する。Next, a method for manufacturing the structure of the present invention will be described with reference to FIG. First, selective growth using SiO 2 as a mask will be described by taking an InGaAsP system as an example.
【００１６】図３（ａ）に示すようなパターンのＳｉＯ
2 マスク２１を有するＩｎＰ基板２２上にＩｎＧａＡｓ
Ｐを選択成長する場合、図３（ｂ）に示すようにマスク
パターンの間のストライプ状の開口部分２３に成長する
ＩｎＧａＡｓＰの組成はマスクパターン幅ｄにほぼ比例
してパターン幅の広くなるほど長波長になる。図４にそ
の一例として開口部１．５μｍのときのマスク幅Ｗμｍ
と光ガイド層の組成との関係を示した。一方、ＩｎＧａ
ＡｓＰの屈折率は波長が長波長になる程大きくなるの
で、図３（ｃ）に示すようにパターン幅の広い部分程Ｉ
ｎＧａＡｓＰの屈折率ＩｎＧａＡｓＰの屈折率は大きく
なる。SiO having a pattern as shown in FIG.
2 InGaAs on the InP substrate 22 having the mask 21
When selectively growing P, as shown in FIG. 3B, the composition of InGaAsP grown in the stripe-shaped opening 23 between the mask patterns is longer in proportion to the mask pattern width d as the pattern width becomes wider. become. FIG. 4 shows an example of the mask width W μm when the opening is 1.5 μm.
And the composition of the light guide layer are shown. On the other hand, InGa
Since the refractive index of AsP increases as the wavelength becomes longer, as shown in FIG. 3C, the wider the pattern width I is.
Refractive index of nGaAsP InGaAsP has a high refractive index.
【００１７】ところで本発明の分布帰還型レーザは、こ
のような選択成長により形成するＩｎＧａＡｓＰ光ガイ
ド層を有するため、マスクパターン幅の広い共振器端面
では光ガイド層の屈折率が大きく、パターン幅の狭い中
央部分では屈折率は小さくなる。従って、回折格子との
結合係数κは、共振器の中央部分では小さく端面付近で
大きくなる。By the way, since the distributed feedback laser of the present invention has the InGaAsP optical guide layer formed by such selective growth, the refractive index of the optical guide layer is large at the end face of the resonator having a wide mask pattern width, and the pattern width is small. The refractive index becomes smaller in the narrow central portion. Therefore, the coupling coefficient κ with the diffraction grating is small in the central part of the resonator and large in the vicinity of the end face.
【００１８】このようにκの分布を最適化することによ
り、光共振器内部の光強度分布が均一となり、空間的ホ
ールバーニングの影響を受けにくくなるので、電流−光
出力特性の直線性は良くなる。By optimizing the distribution of κ in this way, the light intensity distribution inside the optical resonator becomes uniform and the influence of spatial hole burning is less likely to occur, so that the linearity of the current-optical output characteristic is good. Become.
【００１９】更に、中央部分では光ガイド層の等価屈折
率は端面付近に比べ小さいので、光共振器内での光の波
長は、中央部分で長くなり、実質的に位相シフトを導入
したのもと等価な効果が得られる。位相シフト量をλ／
４とすることにより、安定な単一軸モード発振を得るこ
とができる。Further, since the equivalent refractive index of the optical guide layer in the central portion is smaller than that in the vicinity of the end face, the wavelength of light in the optical resonator becomes long in the central portion, and the phase shift is substantially introduced. An effect equivalent to is obtained. Phase shift amount is λ /
By setting it to 4, stable single axis mode oscillation can be obtained.
【００２０】[0020]
【実施例】本発明の分布帰還型レーザについて詳細に説
明する。The distributed feedback laser of the present invention will be described in detail.
【００２１】まず図６、図７を用いて製造方法を説明す
る。はじめにｎ−ＩｎＰ基板１上に光干渉露光法により
均一な回折格子４を形成する。First, the manufacturing method will be described with reference to FIGS. First, a uniform diffraction grating 4 is formed on the n-InP substrate 1 by an optical interference exposure method.
【００２２】次に図６（ａ）に示すように、幅１．５μ
ｍのストライプ状の開口部６をもつＳｉＯ2 マスク５を
ｎ−ＩｎＰ基板１上に形成する。マスク５の幅は中央部
で２μｍ、端面部で５μｍとした。Next, as shown in FIG. 6A, the width is 1.5 μm.
A SiO 2 mask 5 having m stripe-shaped openings 6 is formed on the n-InP substrate 1. The width of the mask 5 was 2 μm at the center and 5 μm at the end face.
【００２３】次に図６（ｂ）に示したように減圧ＭＯＶ
ＰＥ法による選択成長によりＩｎＧａＡｓＰ光ガイド層
２を形成する。Next, as shown in FIG. 6B, the reduced pressure MOV
The InGaAsP light guide layer 2 is formed by selective growth by the PE method.
【００２４】次に図６（ｃ）（ｄ）に示すように、Ｓｉ
Ｏ2 マスク５を除去した後、更にｎ−ＩｎＰスペーサ層
７（層厚０．０４μｍ）、多重量子井戸（ＭＱＷ）活性
層３（ＩｎＧａＡｓＰウェル（λｇ＝１．４０μｍ）、
６２オングストローム、ＩｎＧａＡｓＰバリア（λｇ＝
１．１３μｍ）、１００オングストローム、ウェル数
７）、ｐ−ＩｎＰクラッド層８（層厚０．７μｍ）を成
長する。Next, as shown in FIGS. 6C and 6D, Si
After removing the O 2 mask 5, the n-InP spacer layer 7 (layer thickness 0.04 μm), the multiple quantum well (MQW) active layer 3 (InGaAsP well (λg = 1.40 μm),
62 Å, InGaAsP barrier (λg =
1.13 μm), 100 angstrom, well number 7), and p-InP clad layer 8 (layer thickness 0.7 μm) is grown.
【００２５】次に図７（ａ）に示すように、液相エピタ
キシャル成長（ＬＰＥ）により、ｐ−ＩｎＰ層９（層厚
０．３μｍ）、ｎ−ＩｎＰ層１０（層厚０．２μｍ）、
ｐ−ＩｎＰ層１１（層厚０．３μｍ）、ｐ−ＩｎＧａＡ
ｓＰ層１２（層厚１．０μｍ）を成長し、ＤＣ−ＰＢＨ
構造を形成する。メサ電極を作製するためのエッチング
用マスク１３を形成する。Next, as shown in FIG. 7A, by liquid phase epitaxial growth (LPE), the p-InP layer 9 (layer thickness 0.3 μm), the n-InP layer 10 (layer thickness 0.2 μm),
p-InP layer 11 (layer thickness 0.3 μm), p-InGaA
sP layer 12 (layer thickness 1.0 μm) is grown and DC-PBH
Form a structure. An etching mask 13 for forming a mesa electrode is formed.
【００２６】図７（ｂ）に示すように、ｎ−ＩｎＰ基板
１に達するまで、エッチングし、図７（ｃ）のように、
エッチングマスク１３を除去した後、絶縁マスク１４を
形成し、メサ部に電極形成用の開口部あけ、メサ電極１
５を形成する。As shown in FIG. 7B, etching is performed until the n-InP substrate 1 is reached, and as shown in FIG.
After removing the etching mask 13, an insulating mask 14 is formed, an opening for forming an electrode is opened in the mesa portion, and the mesa electrode 1 is formed.
5 is formed.
【００２７】ＩｎＰ基板を約１５０μｍ厚まで研磨し、
電極１６を形成する。共振器長が約３００μｍとなるよ
うにへき開し、図５に全体の斜視図を示した本発明のレ
ーザが完成する。Polish the InP substrate to a thickness of about 150 μm,
The electrode 16 is formed. Cleaving is performed so that the cavity length is about 300 μm, and the laser of the present invention whose entire perspective view is shown in FIG. 5 is completed.
【００２８】製作された素子は電流−光出力特性におい
て良好な直線性が得られ、アナログ変調として最適であ
る。The manufactured element has good linearity in current-light output characteristics, and is optimal as an analog modulation.
【００２９】本実施例において、光共振器の中央部分で
光ガイド層の波長が短波長となるように設定した。ここ
でいう中央部分とは、共振器の中央から、その前後の共
振器長の１０％の長さの間にはいる部分をさす。この領
域に最短波長部分があり、端面に向かって長波長となっ
ていれば、本願発明の効果が得られる。In this embodiment, the wavelength of the optical guide layer is set to be a short wavelength in the central portion of the optical resonator. The central portion here refers to a portion that is inserted between the center of the resonator and 10% of the resonator length before and after the center. If there is a shortest wavelength portion in this region and the wavelength becomes longer toward the end face, the effect of the present invention can be obtained.
【００３０】また本実施例ではレーザ端面にコーティン
グを行わなかったが、片面に１％、他方の面に７５％の
反射率のコーティングを施すことにより、発光効率の向
上、または高光出力化することができる。この場合共振
器方向での電界分布は不均一になるが、光ガイド層の組
成の制御により、改善できる。従って、必要な発光効率
と直線性の特性に応じて、光ガイド層の組成と、端面コ
ーティングの反射率を比べれば、高出力特性と直線性の
ともに優れた半導体レーザが得られる。Although the laser end face is not coated in this embodiment, the luminous efficiency is improved or the light output is increased by coating the one face with the reflectance of 1% and the other face with the reflectance of 75%. You can In this case, the electric field distribution in the cavity direction becomes non-uniform, but it can be improved by controlling the composition of the optical guide layer. Therefore, by comparing the composition of the light guide layer with the reflectance of the end face coating according to the required luminous efficiency and linearity characteristics, a semiconductor laser having both high output characteristics and linearity can be obtained.
【００３１】[0031]
【発明の効果】本発明によれば、安定な単一モード発振
と直線性の良い低歪特性の半導体レーザが得られる。ま
た本発明の製造方法では選択成長による光ガイド層の組
成の制御でκを設計できるので歩留り良く、再現性良く
製作することができる。According to the present invention, it is possible to obtain a stable single mode oscillation and a semiconductor laser having a low distortion characteristic with good linearity. Further, in the manufacturing method of the present invention, since κ can be designed by controlling the composition of the optical guide layer by selective growth, it can be manufactured with good yield and reproducibility.
【図１】本発明を説明するための図。（ａ）は共振器方
向の断面図、（ｂ）は光ガイド層の共振器方向のバンド
ギャップ波長分布を示す図。FIG. 1 is a diagram for explaining the present invention. (A) is sectional drawing in the resonator direction, (b) is a figure which shows the band gap wavelength distribution of the optical guide layer in the resonator direction.
【図２】本発明の原理を説明するための図。（ａ）は光
ガイド層のλｇの共振器方向の分布を示す図。（ｂ）は
回折格子のκの分布図。（ｃ）は光強度分布図。（ｄ）
は素子の電流−光出力特性を示す図。FIG. 2 is a diagram for explaining the principle of the present invention. FIG. 6A is a diagram showing the distribution of λg of the optical guide layer in the resonator direction. (B) is a distribution diagram of κ of the diffraction grating. (C) is a light intensity distribution chart. (D)
FIG. 4 is a diagram showing current-light output characteristics of the element.
【図３】本発明の原理を説明するための図。（ａ）は光
ガイド層の製作工程を上からみた図。（ｂ）は共振器方
向の光ガイド層のλｇ分布を示す図。（ｃ）は光ガイド
層の屈折率分布を示す図。FIG. 3 is a diagram for explaining the principle of the present invention. (A) is the figure which looked at the manufacturing process of a light guide layer from the top. FIG. 6B is a diagram showing a λg distribution of the optical guide layer in the resonator direction. (C) is a figure which shows the refractive index distribution of a light guide layer.
【図４】ＳｉＯ2 マスク幅ＷとＩｎＧａＡｓＰ光ガイド
層のバンドギャップ波長の関係を示す図。FIG. 4 is a diagram showing a relationship between a SiO 2 mask width W and a bandgap wavelength of an InGaAsP optical guide layer.
【図５】本発明の分布帰還型半導体レーザの斜視図。FIG. 5 is a perspective view of a distributed feedback semiconductor laser of the present invention.
【図６】本発明のレーザの製造工程を説明するための
図。FIG. 6 is a view for explaining the manufacturing process of the laser of the present invention.
【図７】本発明のレーザの製造工程を説明するための
図。FIG. 7 is a drawing for explaining the manufacturing process of the laser of the present invention.
１ ｎ−ＩｎＰ基板 ２ 光ガイド層 ３ 活性層 ４ 回折格子 ５ マスク ６ 開口部 ７ スペーサ層 ８ クラッド層 ９ ｐ−ＩｎＰ層 １０ ｎ−ＩｎＰ層 １１ ｐ−ＩｎＰ層 １２ ｐ−ＩｎＧａＡｓＰ層 １３ マスク １４ 絶縁マスク １５ 電極 １６ 電極 ２１ マスク ２２ 基板 ２３ 開口部 1 n-InP substrate 2 Optical guide layer 3 Active layer 4 Diffraction grating 5 Mask 6 Opening 7 Spacer layer 8 Cladding layer 9 p-InP layer 10 n-InP layer 11 p-InP layer 12 p-InGaAsP layer 13 Mask 14 Insulation Mask 15 Electrode 16 Electrode 21 Mask 22 Substrate 23 Opening
Claims (2)
ーティングとを有し、前記光ガイド層のバンドギャップ
波長が、共振器方向で中央部分から共振器端面に近づく
につれて長波長となっていることを特徴とする分布帰還
型半導体レーザ。1. A bandgap wavelength of at least an optical guide layer, an active layer and a grating, wherein the bandgap wavelength of the optical guide layer becomes longer as it approaches the resonator end face from the central portion in the resonator direction. A distributed feedback semiconductor laser.
に、ストライプ状の開口部を有し、全体の幅が共振器の
両端部分で広く、中央部分で狭いパターンの絶縁膜を形
成する工程と、気相成長法により前記ストライプ状の開
口部に光ガイド層を選択成長する工程と、前記絶縁膜を
除去し、活性層、クラッド層を含む半導体を成長する工
程と、少なくとも１つのｐ型電極とｎ型電極をそれぞれ
形成する工程とを有することを特徴とする分布帰還型半
導体レーザの製造方法。2. A step of forming an insulating film having a stripe-shaped opening on a surface of a semiconductor having a grating, the width of which is wide at both ends of the resonator and narrow at the center, and a vapor phase. A step of selectively growing an optical guide layer in the stripe-shaped opening by a growth method, a step of removing the insulating film and growing a semiconductor including an active layer and a clad layer, at least one p-type electrode and an n-type A method for manufacturing a distributed feedback semiconductor laser, comprising the steps of forming electrodes respectively.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4292851A JPH0770789B2 (en) | 1992-10-30 | 1992-10-30 | Distributed feedback semiconductor laser and manufacturing method thereof |
| US08/144,038 US5394429A (en) | 1992-10-30 | 1993-11-01 | Distributed-feedback laser with improved analog modulation distortion characteristics and method for fabricating the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4292851A JPH0770789B2 (en) | 1992-10-30 | 1992-10-30 | Distributed feedback semiconductor laser and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06196798A JPH06196798A (en) | 1994-07-15 |
| JPH0770789B2 true JPH0770789B2 (en) | 1995-07-31 |
Family
ID=17787194
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4292851A Expired - Fee Related JPH0770789B2 (en) | 1992-10-30 | 1992-10-30 | Distributed feedback semiconductor laser and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0770789B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0936496A (en) * | 1995-07-21 | 1997-02-07 | Nec Corp | Semiconductor light emitting element and fabrication thereof |
| JP2008066620A (en) * | 2006-09-11 | 2008-03-21 | Nec Electronics Corp | Semiconductor laser and manufacturing method therefor |
| JP6050607B2 (en) * | 2012-05-15 | 2016-12-21 | 株式会社アマダミヤチ | Laser processing apparatus and laser output calibration method |
| JP2018006440A (en) * | 2016-06-29 | 2018-01-11 | 日本電信電話株式会社 | Semiconductor laser |
-
1992
- 1992-10-30 JP JP4292851A patent/JPH0770789B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06196798A (en) | 1994-07-15 |
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