JPH02220490A - Semiconductor laser - Google Patents
Semiconductor laserInfo
- Publication number
- JPH02220490A JPH02220490A JP4248189A JP4248189A JPH02220490A JP H02220490 A JPH02220490 A JP H02220490A JP 4248189 A JP4248189 A JP 4248189A JP 4248189 A JP4248189 A JP 4248189A JP H02220490 A JPH02220490 A JP H02220490A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- quantum well
- quantum
- well layer
- spike
- 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.)
- Pending
Links
- 239000004065 semiconductor Substances 0.000 title claims description 15
- 230000004888 barrier function Effects 0.000 claims abstract description 20
- 230000010355 oscillation Effects 0.000 abstract description 12
- 230000005283 ground state Effects 0.000 abstract description 8
- 230000005476 size effect Effects 0.000 abstract description 6
- 230000005284 excitation Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 8
- 238000005253 cladding Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 3
- 238000005036 potential barrier Methods 0.000 description 3
- 238000005381 potential energy Methods 0.000 description 2
- 241001649081 Dina Species 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
Landscapes
- Semiconductor Lasers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野１
この発明は、半導体レーザに関し、特にその発振波長の
短波長化に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a semiconductor laser, and particularly to shortening its oscillation wavelength.
〔従来の技術１
第２図は、例えば雑誌（Ｉ］ＩＥ Ｊｏｕｒｎａｌｏｒ
Ｑｕａｎｔｕｍ ｇｌｅｃｔｒｏｎｉｃｓ、ＶＯｌ、Ｑ
Ｉ−２０，Ｎ０ＩＯ，１０月、１９８４年、第１１１９
頁）に掲載された半導体レーザのポテンシャシダイアグ
ラム及び基底量子状態の包絡関数を示す説明図である。[Prior art 1 Figure 2 shows, for example, a magazine (I] IE Journalor
Quantum glectronics, VOl, Q
I-20, N0IO, October, 1984, No. 1119
FIG. 2 is an explanatory diagram showing a potential diagram of a semiconductor laser and an envelope function of a fundamental quantum state published in 2003, page).
この半導体レーザは従来の量子井戸層を活性層に含むも
のであり、図に訃いて、（１）は量子井戸層、（２）は
障壁層、（３）はクラッド層、（５）は活性層を含む光
ガイド層である。この図は矢印Ｘ方向に伝導帯ポテンシ
ャルエネルギーを示している。This semiconductor laser includes a conventional quantum well layer as an active layer, and as shown in the figure, (1) is a quantum well layer, (2) is a barrier layer, (3) is a cladding layer, and (5) is an active layer. A light guide layer comprising a layer. This figure shows the conduction band potential energy in the direction of the arrow X.
量子井戸層（１）は障壁層Ｃ）で閉じ込める構造となっ
ており、活性層を含む巾Ｗからなる光ガイド層（５）は
両側に形成されたクツラド層（３）Ｋより構成される。The quantum well layer (1) has a structure in which it is confined by a barrier layer C), and the optical guide layer (5) having a width W including the active layer is composed of Kuturad layers (3) K formed on both sides.
このような構成の半導体Ｖ−ザのレーザ発振に関与する
エネルギー単位は、量子サイズ効果によって決まること
が雑誌（１Ｐｅｓｔｋｏｒｐｅｒ ｐｒｏｂｌｅｍｅＸ
Ｖ、 Ｐｅｒｇａｍｏｎ−Ｖｉｅｗｅ（、Ｒ，Ｄｉｎｇ
ｌｅ、 １９７５ ）に報告されている。これによれば
、量子井戸層（１）を構成する半導体のエネルギーギヤ
ラグをＫｇとすると、ＥＱｗ ＝ Ｅｑ＋ ｊｌｃＢ
＋ ＩＥｖｃ−（、”’（１）Ｃ■ｒ。A magazine (1Pestkorper problem
V, Pergamon-View (, R, Ding
Le, 1975). According to this, if the energy gear lag of the semiconductor constituting the quantum well layer (1) is Kg, then EQw = Eq+ jlcB
+ IEvc-(,"'(1)C■r.
で表わされる。ここで、ΔＥ＝ゎ２．及びΔ＜’ｍｆｆ
、は量子サイズ効果によって決まる。It is expressed as Here, ΔE=ゎ2. and Δ<'mff
, is determined by quantum size effects.
伝導帯（Ｃ，Ｂ、）及び価電子帯（Ｖ、Ｂ、）のエネル
ギーギャップ増加分である。この’ ”’ｃｏｏ ｆ、
、又はΔ％ｏｔ＋ｔは例えば有効質量近似では
と近似的にあられされる。ここで、ｍｌは伝導帯又は価
電子帯の有効質量、Ｌｚは量子井戸の厚さ、ｈはデイフ
ック定数（プフンク定数ｈ ／２πに等しい）、ｎは整
数である。This is an increase in the energy gap of the conduction band (C, B,) and the valence band (V, B,). This'”'coo f,
, or Δ%ot+t can be approximately expressed as, for example, in the effective mass approximation. Here, ml is the effective mass of the conduction band or valence band, Lz is the thickness of the quantum well, h is Dehook's constant (equal to Pfunk's constant h 2 /2π), and n is an integer.
次に動作について説明する。クラッド層（３）より注入
される電子又は正孔は急速にフォノンの放出等によりエ
ネルギー緩和し、活性層内の基底量子単位（ｎ＝１に相
当する）を占有するので、口＝１量子単位を占有する電
子と正孔間での発光再結合が主とな抄、注入キャリアー
密度がレーザ発振しきい値を越えるとレーザ発振に至る
。この時の発振波長λ七（ａｍ）は
λ洲：１．２４／ｆＮ′（ｅｖ）・・・（３）で決まり
、ΔＥｃ益に相当するエネルギー分だけ発振波長は短波
長化される。Next, the operation will be explained. Electrons or holes injected from the cladding layer (3) rapidly relax their energy due to phonon emission, etc., and occupy the base quantum unit (corresponding to n = 1) in the active layer, so that the number of holes is 1 quantum unit. When the injected carrier density exceeds the laser oscillation threshold, laser oscillation occurs. The oscillation wavelength λ7 (am) at this time is determined by λ:1.24/fN'(ev) (3), and the oscillation wavelength is shortened by the energy corresponding to the ΔEc gain.
〔発明が解決しようとする課題ｌ
従来の半導体レーザは以上のように構成されているので
、ｎ＝１の最底次の量子単位が基底状態となるために、
レーザ発振は口＝１で安定に起こり易く、短波長化を実
現するためにΔＥｉ を太きＣｏ口Ｃ
くすることが一般には困難であるという問題点があった
。[Problem to be solved by the invention l Since the conventional semiconductor laser is configured as described above, since the lowest order quantum unit of n=1 becomes the ground state,
Laser oscillation tends to occur stably when the opening is 1, and there is a problem in that it is generally difficult to increase ΔEi to a thick Co opening C in order to shorten the wavelength.
この発明は上記のような問題点を解消するためになされ
たもので、疑似的にｎ＝２と等価な量子単位を基底状態
としてつくり、従来の方法に比べ、少なくとも４倍以上
量子サイズ効果によるエネルギーギャップ増加分ｊＥ、
。。２．を大きくできる活性層を有し、短波長化が容易
に実現できる半導体Ｖ−ザを得ることを目的とする。This invention was made to solve the above-mentioned problems, and it creates a quantum unit pseudo-equivalent to n=2 as a ground state, and the quantum size effect is at least 4 times greater than that of the conventional method. Energy gap increase jE,
. . 2. An object of the present invention is to obtain a semiconductor V-diode having an active layer capable of increasing the wavelength and easily realizing a short wavelength.
〔課題を解決するための手段ｊ
この発明に係る半導体レーザは、量子井戸層の内部にス
パイク状の分布をもつ障壁層を設けたものである。[Means for Solving the Problems j] A semiconductor laser according to the present invention is provided with a barrier layer having a spike-like distribution inside a quantum well layer.
［ｆｉｒ用１
この発Ｆ１４における半導体レーザは、スパイク障壁を
設けることにより量子サイズ効果によるエネルギーギャ
ップ上外分が大きくなり、レーザ発振波長の短波長化が
得られる。[For fir 1 In this F14 semiconductor laser, by providing a spike barrier, the upper and outer parts of the energy gap are increased due to the quantum size effect, and the laser oscillation wavelength can be shortened.
［ｌ！施例１
以下、この発明の一実施例を図について説明する。第２
図は、例えばＧａＡｓ／Ａｌ（Ｇａ）Ａｓ半導体レーザ
のポテンシャルダイアダラム及び基底量子状態の包絡関
数を示す説明図である５図において（１）は厚さＬｚの
Ｇａ Ａｓ量子井戸層、■）は厚さＬＢのＡｌｘ１Ｇａ
Ｉ−ｘＩＡＩｌ障壁層、（３）はＡＬｘ２Ｇａ ｌ −
ｘ２ クラッド層であや、０〈ｘｌ ＜ Ｘ２の関係に
ある。（４）は量子井戸層（１）の中央に設けられた厚
さＬ贋のＡＬＡｓスパイク障壁層である。[l! Example 1 An example of the present invention will be described below with reference to the drawings. Second
The figure is an explanatory diagram showing, for example, the potential diagram and the envelope function of the fundamental quantum state of a GaAs/Al(Ga)As semiconductor laser. In Figure 5, (1) is a GaAs quantum well layer with a thickness of Lz, and Alx1Ga with thickness LB
I-xIAIl barrier layer, (3) is ALx2Gal-
x2 In the cladding layer, there is a relationship of 0<xl<X2. (4) is an ALA spike barrier layer with a thickness L provided in the center of the quantum well layer (1).
Ｌ８がゼロのときは、第１図と同じＬｚ厚さの量子井戸
層（１）が形成され、基底状態はｎ＝１量子単位となる
。この口＝１量子単位に相当する固有状顔の波長関数は
、Ｒ，Ｄｉｎａ；ｌｅによると障壁層（２）との境界で
確率密度がゼロに近く、中央部で最大となる包絡関数（
ｅｎｖｅｌｏｐｅｆ’ｕｎｃｔｉｏｎ ）となっている
。この時の包絡関数を第２図曲線Ａに示している。この
量子井戸層（１）の中央に第１図に示したように１層の
スパイク状の障壁層（４）を導入すると、基底状態の波
長関数は量子井戸層（１）の中央で節を持つ包絡関数が
得られる。この時の包絡関数を曲線Ｂに示すうこれは、
第１図に示す量子井戸層（１）でのｎ＝２の励起量子単
位の包絡関数に相当し、スパイク状の障壁層（４）の導
入により量子井戸層（１）の中央に節をもつ包絡関数が
基底状態として安定化されたことになる。When L8 is zero, a quantum well layer (1) with the same thickness Lz as in FIG. 1 is formed, and the ground state is n=1 quantum unit. According to R, Dina; le, the wavelength function of the eigenface corresponding to this mouth = 1 quantum unit is the envelope function (
envelope function). The envelope function at this time is shown in curve A in Figure 2. When a spike-shaped barrier layer (4) is introduced at the center of the quantum well layer (1) as shown in Figure 1, the wavelength function of the ground state becomes a node at the center of the quantum well layer (1). The enveloping function with is obtained. The envelope function at this time is shown in curve B, which is
It corresponds to the envelope function of n = 2 excited quantum units in the quantum well layer (1) shown in Figure 1, and has a node in the center of the quantum well layer (1) due to the introduction of a spike-shaped barrier layer (4). This means that the envelope function has been stabilized as a ground state.
次に動作について説明する。Next, the operation will be explained.
クラッド層（３）よシ注入された電子又は正孔は活性層
内の基底量子単位を占有し、従来と同様の方法によりレ
ーザ発振する。この時、発振波長は基底量子単位となっ
ている。ところで、この実施例では量子井戸層（１）の
中央に節をもつ包絡関数を基底状態とし、量子単位がス
パイク状の障壁層（４）全導入している。このため、式
（２）でｎ＝２に相当するｄｍ １（ｎ＝２）とｉｗ
ｃ山Ｃ（ｎ＝ １ ）の違いにより、約αｍ巳
４倍だけ量子サイズ効果による量子単位エネルギーｍ′
の増大が式（１）より得られる。従って、式（３）によ
りＥＱＷの増大した分だけλ の短波長化が得ＬＪ）
られる。Electrons or holes injected through the cladding layer (3) occupy fundamental quantum units in the active layer, and laser oscillation occurs in a conventional manner. At this time, the oscillation wavelength is a fundamental quantum unit. Incidentally, in this embodiment, the ground state is an envelope function having a node at the center of the quantum well layer (1), and the barrier layer (4) in which the quantum units are spike-shaped is completely introduced. Therefore, in equation (2), dm 1 (n=2) and iw corresponding to n=2
Due to the difference in the c-mountain C (n = 1), the quantum unit energy m' due to the quantum size effect is increased by approximately αm4 times.
can be obtained from equation (1). Therefore, according to equation (3), the wavelength of λ can be shortened by the increase in EQW (LJ).
このようにこの実施例では、量子井戸活性層（５）の中
央にスパイク状のポテンシャル障壁層（４）を設けたの
で、疑似的にｎ＝２と等価な量子状態を基底量子状態と
して強制的に作ることになり、量子サイズ効果による閉
じ込めエネルギーを著しく増大させることができる。こ
のため、レーザ発振波長を短波長化することができる。In this example, since the spike-like potential barrier layer (4) is provided in the center of the quantum well active layer (5), a pseudo quantum state equivalent to n=2 is forced as the base quantum state. This makes it possible to significantly increase the confinement energy due to the quantum size effect. Therefore, the laser oscillation wavelength can be shortened.
なお、上記５ｉ！施例では量子井戸層（１）中にスパイ
ク状のポテンシャル障壁層（４）を１層だけ設けた場合
を示したが、２層以上のスパイク状ポテンシャル障壁層
を設けるてもよい。２層以上設けることにより、疑似的
に、スパイク障壁層を設けない時のロー３．ｖ＝４・・
・と等価な量子状態を大意的に基底量子状態として作る
ことができ、上記実施例と同様の効果を奏することがで
きる。また、上記実施例では、量子井戸層（１）がＧａ
Ａｓ、スパイク障壁層（４）がＡｌＡｓの場合の例を示
したが、これに限るものではない。例えば活性層、量子
井戸層（１）がＡｌＸ０Ｇａｌ−ｘｎＡｓ（０＜ｘｏ＜
０．４ ’またはＧｓ Ａｓと格子整合するシｙｌ （
ＡｌｘＧａ＋−ｘ）＋−ｙ、Ｐからなり、ＧａＡｓと格
子整合しなＩｎｙ２（ＡｌｘＧａ＋ −Ｘ） １−７２
Ｐ （ｙ ｒ ＞ ｙ ２１またはＡｌｘｚＧａｌ−
ｘｚＡａ （０〈Ｘ２≦１）を障壁層（４）とした場合
も、上記実施例と同様の効果を奏する。In addition, the above 5i! Although the example shows the case where only one spike-like potential barrier layer (4) is provided in the quantum well layer (1), two or more spike-like potential barrier layers may be provided. By providing two or more layers, it is possible to simulate low 3.0 when no spike barrier layer is provided. v=4...
A quantum state equivalent to . . Further, in the above embodiment, the quantum well layer (1) is made of Ga.
Although an example is shown in which the spike barrier layer (4) is made of AlAs, the invention is not limited to this. For example, the active layer and quantum well layer (1) are made of AlX0Gal-xnAs (0<xo<
0.4' or lattice-matched to Gs As (
Iny2(AlxGa+ -X) 1-72, which consists of AlxGa+-x)+-y, P and is not lattice-matched to GaAs.
P (y r > y 21 or AlxzGal-
Even when xzAa (0<X2≦1) is used as the barrier layer (4), the same effects as in the above embodiment can be obtained.
〔発明の効果１
以上のように、この発明によれば、量子井戸層を活性層
に含む半導体レーザにおいて、量子井戸層の内部にスパ
イク状の分布をもつ障壁層を設けたので、基底量子準位
エネルギーの量子閉じ込め効果による増大が起こり、レ
ーザ発振波長の短波長化を実現できる半導体レーザを得
ることができる効果がある。[Effect of the invention 1 As described above, according to the present invention, in a semiconductor laser including a quantum well layer in the active layer, a barrier layer having a spike-like distribution is provided inside the quantum well layer, so that the fundamental quantum standard is This has the effect of making it possible to obtain a semiconductor laser that can achieve a shortened laser oscillation wavelength by increasing the potential energy due to the quantum confinement effect.
第１図はこの発明の一実施例による量子井戸層４体レー
ザのポテンシャルダイアグラム及び基底量子状類の包絡
関数を示す説明図、第２図は従来の量子井戸半導体レー
ザのポテンシャルダイアグラム及び基底量子状態の包絡
関数を示す説明図である。
図において、（１）は量子井戸層、（２）は障壁層、（
３）はクラッド層、（４）はスパイク状の分布を有する
障壁層である。
なお、図中、同一符号は同一、又は相当部分を示す。
第１図
第２図FIG. 1 is an explanatory diagram showing a potential diagram and an envelope function of the basis quantum state of a four-layer quantum well laser according to an embodiment of the present invention, and FIG. 2 is a potential diagram and a basis quantum state of a conventional quantum well semiconductor laser. It is an explanatory diagram showing an envelope function of. In the figure, (1) is a quantum well layer, (2) is a barrier layer, (
3) is a cladding layer, and (4) is a barrier layer having a spike-like distribution. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Figure 1 Figure 2
Claims (1)
量子井戸層の内部にスパイク状の分布を持つ障壁層を有
することを特徴とする半導体レーザ。1. A semiconductor laser including a quantum well layer in an active layer, the semiconductor laser having a barrier layer having a spike-like distribution inside the quantum well layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4248189A JPH02220490A (en) | 1989-02-21 | 1989-02-21 | Semiconductor laser |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4248189A JPH02220490A (en) | 1989-02-21 | 1989-02-21 | Semiconductor laser |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02220490A true JPH02220490A (en) | 1990-09-03 |
Family
ID=12637254
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4248189A Pending JPH02220490A (en) | 1989-02-21 | 1989-02-21 | Semiconductor laser |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02220490A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011064475A1 (en) * | 2009-11-27 | 2011-06-03 | Centre National De La Recherche Scientifique - Cnrs | Laser emission system, heterostructure and active zone having coupled quantum sub-wells, and use for 1.55 μm laser emission |
-
1989
- 1989-02-21 JP JP4248189A patent/JPH02220490A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011064475A1 (en) * | 2009-11-27 | 2011-06-03 | Centre National De La Recherche Scientifique - Cnrs | Laser emission system, heterostructure and active zone having coupled quantum sub-wells, and use for 1.55 μm laser emission |
| FR2953335A1 (en) * | 2009-11-27 | 2011-06-03 | Centre Nat Rech Scient | LASER EMISSION SYSTEM, HETEROSTRUCTURE AND ACTIVE ZONE WITH QUANTIC COUPLED SUB-WELLS, USE FOR 1.55 MICROMETER LASER EMISSION |
| US9099842B2 (en) | 2009-11-27 | 2015-08-04 | Centre National de la Recherche Scientifique—CNRS | Laser emission systems, heterostructure and active zone having coupled quantum-wells, and use for 1.55 mm laser emission |
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