JPH0467355B2 - - Google Patents
Info
- Publication number
- JPH0467355B2 JPH0467355B2 JP4340184A JP4340184A JPH0467355B2 JP H0467355 B2 JPH0467355 B2 JP H0467355B2 JP 4340184 A JP4340184 A JP 4340184A JP 4340184 A JP4340184 A JP 4340184A JP H0467355 B2 JPH0467355 B2 JP H0467355B2
- Authority
- JP
- Japan
- Prior art keywords
- refractive index
- active layer
- layer
- inp
- semiconductor 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
Links
- 239000004065 semiconductor Substances 0.000 claims description 16
- 238000003776 cleavage reaction Methods 0.000 claims 2
- 230000007017 scission Effects 0.000 claims 2
- 230000010355 oscillation Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- MODGUXHMLLXODK-UHFFFAOYSA-N [Br].CO Chemical compound [Br].CO MODGUXHMLLXODK-UHFFFAOYSA-N 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 238000001947 vapour-phase growth Methods 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
- H01S5/20—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
-
- 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
- H01S5/20—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
- H01S5/2275—Buried mesa structure ; Striped active layer mesa created by etching
Landscapes
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Optics & Photonics (AREA)
- Geometry (AREA)
- Semiconductor Lasers (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明は半導体発光装置に係り特に縦モードの
安定化を計つた半導体レーザに関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semiconductor light emitting device, and particularly to a semiconductor laser whose longitudinal mode is stabilized.
従来例の構成とその問題点
従来より半導体レーザの縦モードの制御のため
にDFB（distributed feed back）構造という方法
がとられていた。この方法は電流を注入する部分
に周期的な屈折率変化（コルゲーシヨン）を与え
ることにより、分布的な光の帰還を生じさせ、発
振を得るものである。DFBレーザにおいて得ら
れる発振波長λと、屈折率変化の周期へとの関係
は、
λ＝2nλ／ｍ
ただし、ｎ：活性層の屈折率、ｍ：ブラツグ回
折の次数
の関係で決まり、この発振波長λで単一波長発振
の縦モード動作が安定に行われる。しかしながら
結晶へのコルゲーシヨンの形成は、その周期が
1.3μm帯レーザにおいては、式からわかるように
ｍ＝１とすれば、2000Å程度と極めて小さく微細
加工技術が必要であり、製造工程が複雑となると
いう欠点があり、まだ実用に至つていない。Conventional configuration and its problems Conventionally, a method called a DFB (distributed feed back) structure has been used to control the longitudinal mode of a semiconductor laser. In this method, a periodic refractive index change (corrugation) is given to the part into which a current is injected, thereby causing distributed light feedback and obtaining oscillation. The relationship between the oscillation wavelength λ obtained in a DFB laser and the period of refractive index change is determined by the relationship between λ=2nλ/m, where n: the refractive index of the active layer, m: the order of Bragg diffraction, and this oscillation wavelength Longitudinal mode operation with single wavelength oscillation is performed stably at λ. However, the periodicity of the formation of corrugations in crystals is
As you can see from the formula, if m = 1, the 1.3 μm band laser is extremely small, about 2000 Å, and requires microfabrication technology, making the manufacturing process complicated, so it has not yet been put into practical use. .
発明の目的
本発明は、微細加工技術を必要とせず、またコ
ルゲーシヨンをもたない構造で縦モードの安定化
を計つた半導体レーザ素子を提供せんとするもの
である。OBJECTS OF THE INVENTION The present invention aims to provide a semiconductor laser device that does not require microfabrication technology and has a structure that does not have corrugation and stabilizes the longitudinal mode.
発明の構成
本発明は活性層（屈折率n1）の一部を屈折率n2
の半導体でおきかえ、活性層および屈折率n2も含
めて全体を屈折率n3の半導体で埋め込んだことで
ある。そして各種の屈折率の値の関係を
n1＞n2＞n3
とした半導体レーザであり、共振器内の活性層中
の発振光は、屈折率n2の層において一部は反射、
一部は透過し両者の干渉によつて発振利得は強い
選択性をもち、縦モードの単一化が実現される。
また、屈折率n2層へ入つた光は、さらに屈折率の
小さな層によつて埋め込まれているため減衰する
こともなく、低しきい値を縦待しうるものであ
る。Structure of the Invention The present invention provides that a part of the active layer (with a refractive index n 1 ) has a refractive index n 2 .
Instead, the entire structure, including the active layer and the refractive index n 2 , was filled with a semiconductor with a refractive index n 3 . It is a semiconductor laser in which the relationship between various refractive index values is n 1 > n 2 > n 3 , and the oscillation light in the active layer in the cavity is partially reflected by the layer with a refractive index of n 2 .
A portion of the light passes through, and due to the interference between the two, the oscillation gain has strong selectivity, and a single longitudinal mode is realized.
Furthermore, since the light entering the layer with a refractive index of n2 is further embedded in layers with a lower refractive index, it is not attenuated and can wait for a low threshold value.
実施例の説明
第１図から第３図は本発明の位置実施例の半導
体レーザの製造過程を示すものであり、第１図に
示すようにｎ−InP基板１上に液相エピタキシヤ
ル成長法によつてｎ−InP２，ｎ−InGaAsP（Eg
〜0.95eV）３，Ｐ−InP４を順次成長させる。こ
のようなエピタキシヤルウエーハにSiO2膜をと
りつけ、さらにホトエツチ法によつてSiO2膜を
幅約2.5μmのストライプ状に選択的にのこし、こ
の膜をマスクとし、ブロムメタノール液によつて
エツチするとネツク部が、活性層となる逆メサ構
造が得られる。これを第２の成長によつて第２図
に示すようにＰ−InP５，Ｐ−InP６で埋め込む
といわゆるBH（Burried Heterostructure）レー
ザが得られる。このようなレーザの共振器面間ほ
ぼ中央に、第３図に示すごとくホトリソグラフイ
の手段により活性層まで到達する溝を形成する。
次に、この溝中にのみ選択的に、ｎ−InGaAsP
（Eg〜1.05eV）及びｎ−InPを成長させる。この
ような成長によつて活性層の一部はｎ−
InGaAsP（Eg〜1.05eV）によつておきかえられ
かつ全体はInPによつて埋め込まれる構造とな
る。尚活性層のｎ−InGaAsP（Eg〜1.05eV）で
おきかえられる領域の長さは、約0.8μmである。DESCRIPTION OF EMBODIMENTS FIGS. 1 to 3 show the manufacturing process of a semiconductor laser according to an embodiment of the present invention. As shown in FIG. n-InP2, n-InGaAsP (Eg
~0.95eV) 3 and P-InP4 are grown sequentially. A SiO 2 film is attached to such an epitaxial wafer, and the SiO 2 film is selectively left in a stripe shape with a width of about 2.5 μm using a photo-etching method. Using this film as a mask, etching is performed using a bromine methanol solution. An inverted mesa structure is obtained in which the network portion becomes the active layer. When this is buried with P-InP5 and P-InP6 through the second growth as shown in FIG. 2, a so-called BH (Burried Heterostructure) laser is obtained. As shown in FIG. 3, a groove reaching the active layer is formed approximately in the center between the resonator surfaces of such a laser by means of photolithography.
Next, n-InGaAsP is selectively added only into this groove.
(Eg ~ 1.05 eV) and grow n-InP. Due to this growth, a part of the active layer becomes n-
The structure is replaced by InGaAsP (Eg ~ 1.05 eV) and the entire structure is embedded with InP. The length of the region of the active layer replaced by n-InGaAsP (Eg~1.05 eV) is approximately 0.8 μm.
第４図は本発明の半導体レーザをさらに詳しく
説明するための模式図である。一対のフアブリペ
ロー共振面７，８の間に活性層３がInP層５によ
つて埋めこまれている。さらに活性層３の中央部
はｎ−InGaAsP（Eg〜1.05eV）９によつておき
かえられている。活性層３のバンドギヤツプEg
は0.95eVであるのでその差は約0.1eVである。 FIG. 4 is a schematic diagram for explaining the semiconductor laser of the present invention in more detail. An active layer 3 is buried between a pair of Fabry-Perot resonance surfaces 7 and 8 by an InP layer 5. Furthermore, the central part of the active layer 3 is replaced with n-InGaAsP (Eg~1.05 eV) 9. Band gap of active layer 3 Eg
is 0.95eV, so the difference is about 0.1eV.
このような構造では、活性層３中の発振光は、
共振器面７，８の間を往復する間に、ｎ−
InGaAsP９において一部は反射、一部は透過し、
お互いの干渉により利得分布は、選択的となり、
縦モードの単一化が容易に得られると共に全体
が、InP層５によつて埋め込まれたすなわち活性
層３の屈折率をn1，ｎ−InGaAsP層９の屈折率
をn2，InP層５の屈折率をn3とすると
n1＞n2＞n3
なる関係となり、全体で一つの導波路となり光の
損失が小さく、しきい値への影響を少なくかつ縦
モードの単一化が可能である。 In such a structure, the oscillation light in the active layer 3 is
While reciprocating between the resonator surfaces 7 and 8, n-
InGaAsP9, part is reflected, part is transmitted,
The gain distribution becomes selective due to mutual interference,
The longitudinal mode can be easily unified, and the whole is buried with the InP layer 5, that is, the refractive index of the active layer 3 is n 1 , the refractive index of the n-InGaAsP layer 9 is n 2 , and the InP layer 5 If the refractive index of is n 3 , then the relationship is n 1 > n 2 > n 3 , and the whole becomes one waveguide with low optical loss, less influence on threshold value, and single longitudinal mode. It is.
第５図は、本発明の半導体レーザの光出力−電
流特性と、縦モードを示したものである。しきい
電流は平均で約20mAであり2mW，6mW，
10mW動作時においても単一性は極めてよく側帯
モードの発生は見られなかつた。 FIG. 5 shows the optical output-current characteristics and longitudinal mode of the semiconductor laser of the present invention. The threshold current is about 20mA on average, 2mW, 6mW,
Even during 10mW operation, the unity was extremely good and no sideband modes were observed.
なお、上記実施例においてはInP基板上に成長
させた、InP／InGaAsPについて述べたが本発明
の主旨にあえば、GaAlAs／GaAs系であつても
良い。 In the above embodiments, InP/InGaAsP grown on an InP substrate was described, but GaAlAs/GaAs may also be used as long as the purpose of the present invention is met.
また実施例においてｎ型とあるのをｐ型に、ｐ
型をｎ型に置きかえても本発明の主旨は満たす。 Also, in the examples, n-type is replaced with p-type.
Even if the type is replaced with an n-type, the gist of the present invention is still satisfied.
また実施例では液相エピタキシヤル成長により
結晶成長を行つたが、気相成長法でも分子線成長
でも良いことは言うまでもない。 Further, in the examples, crystal growth was performed by liquid phase epitaxial growth, but it goes without saying that vapor phase growth or molecular beam growth may be used.
発明の効果
以上のように本発明においては縦モードの良好
な単一性を得られる。Effects of the Invention As described above, in the present invention, good uniformity of the longitudinal mode can be obtained.
第１図〜第３図は本発明の一実施例の半導体レ
ーザの製造過程を示す図、第４図は本発明の一実
施例の半導体レーザの構造模式図、第５図は本発
明の一実施例の半導体レーザの特性図である。
１……ｎ−InP基板、２……ｎ−InP層、３…
…ｎ−InGaAsP活性層、４……Ｐ−InP層、５…
…Ｐ−InP埋込層、６……ｎ−InP埋込層、７，
８……フアブリペロ共振面、９……ｎ−
InGaAsP（Eg〜1.05eV）。
1 to 3 are diagrams showing the manufacturing process of a semiconductor laser according to an embodiment of the present invention, FIG. 4 is a schematic structural diagram of a semiconductor laser according to an embodiment of the present invention, and FIG. It is a characteristic diagram of the semiconductor laser of an Example. 1... n-InP substrate, 2... n-InP layer, 3...
...n-InGaAsP active layer, 4...P-InP layer, 5...
...P-InP buried layer, 6...n-InP buried layer, 7,
8...Fabri-Perot resonance surface, 9...n-
InGaAsP (Eg~1.05eV).
Claims (1)
にてストライプ状の活性層が形成され、前記へき
開面を除いて前記活性層の両側に屈折率n3の半導
体層が形成され、前記活性層の一部が除去された
溝部に、前記活性層と接して屈折率n2の半導体層
が形成され、前記屈折率の関係が、 n1＞n2＞n3 であることを特徴とする半導体レーザ。[Claims] 1. A striped active layer is formed of a semiconductor layer with a refractive index n 1 whose both ends are cleavage planes, and a semiconductor layer with a refractive index n 3 is formed on both sides of the active layer except for the cleavage plane. is formed, and a semiconductor layer with a refractive index n 2 is formed in contact with the active layer in the groove portion from which a part of the active layer is removed, and the relationship of the refractive index is n 1 > n 2 > n 3 . A semiconductor laser characterized by certain things.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59043401A JPS60187080A (en) | 1984-03-07 | 1984-03-07 | semiconductor laser |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59043401A JPS60187080A (en) | 1984-03-07 | 1984-03-07 | semiconductor laser |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60187080A JPS60187080A (en) | 1985-09-24 |
| JPH0467355B2 true JPH0467355B2 (en) | 1992-10-28 |
Family
ID=12662747
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59043401A Granted JPS60187080A (en) | 1984-03-07 | 1984-03-07 | semiconductor laser |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60187080A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0797661B2 (en) * | 1987-09-29 | 1995-10-18 | 沖電気工業株式会社 | Light emitting diode and manufacturing method thereof |
| JP4612448B2 (en) * | 2005-03-25 | 2011-01-12 | 日立電線株式会社 | Semiconductor laser device |
-
1984
- 1984-03-07 JP JP59043401A patent/JPS60187080A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60187080A (en) | 1985-09-24 |
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