JPS606906A - Semiconductor light element - Google Patents

Abstract

PURPOSE:To cause good Bragg's reflection and enable guide of only the light of a selected wavelength by forming a multilayer crystal member obtained by alternately forming mixed crystal layers different in refractive index at prescribed intervals on a mixed crystal semiconductor substrate, with a slope formed on its one side, and forming a light guide layer on this slope. CONSTITUTION:A plurality of InP layers 13 of n1 refractive index and GaInAsP layers 14 of n2 refractive index are alternately grown on a mixed crystal semiconductor substrate 11 of, e.g. to form a multilayer crystal member 12. A slope 15 is formed by grinding or etching one side of said member 12. A light guide layer 16 made of GaInAsP is formed on the upper faces of the slope 15 and the member 12 and the surface of the substrate 11. The sum LAMBDA of the width of the layers 13,14 adjacent to each other on the side of the slope 15 is kept constant and laminated at equal intervals, resulting in guiding only the light of wavelength set with said sum LAMBDA and the difference of refractive indices n1-n2 between the layers 13,14 through the light layer 16. For example, an activated carbon layer 17 and a clad layer 18 are formed successively on the layer 16 and light produced at the layer 17 with a current is introduced into the layer 16 to cause the Bragg's reflection to use it for emission of laser beams, etc.

Description

【発明の詳細な説明】 （技術分野） この発明は半導体光素子、詳しくは波長選択性を有する
半導波路に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a semiconductor optical device, and more particularly to a semi-waveguide having wavelength selectivity.

（・従来技術） 従来のコルゲーション（Ｃｏｒｒｕｇａｔｉｏｎ　）型
光導波路を第１図に示す。この図に示すように従来の上
記光導波路は、結晶１上にし〜ザ光の干渉縞を用いてエ
ツチングによりＡの周期構造を設け、その上に屈折率の
異なる導波層２を成長させている。(Prior Art) A conventional corrugation type optical waveguide is shown in FIG. As shown in this figure, in the conventional optical waveguide, a periodic structure A is provided on a crystal 1 by etching using interference fringes of laser light, and a waveguide layer 2 having a different refractive index is grown on top of the periodic structure A. There is.

しかしガから、このようなコルグージョン型光＝　ｖ　
ｙ＝では、■コルク゛−ジョンの凸凹を充分深くと九々
い、■導波層２を成長する際、熱的に凸凹がくずれて良
好に干渉効果を誘起できない、■凸凹の間隔はレーザ光
の波長によシ制限され、あまり密にできない、という欠
点があった。However, from the moth, such corgousion type light = v
At y=, ■ The corrugation should be deep enough and the convexity should be sufficiently deep. ■ When the waveguide layer 2 is grown, the concavity and convexity will be thermally destroyed and a good interference effect cannot be induced. The disadvantage is that it is limited by the wavelength of

（発明の目的） この発明は上記の点に鑑みなされたもので、従来の欠点
を解決できる半導体光素子を提供することを目的とする
。(Objective of the Invention) The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor optical device capable of solving the conventional drawbacks.

（実施例）　・ 以下この発明の一実施例を図面を参照して説明する。第
２図はこの発明の一実施例を示す図である　この図にお
いて、１１は混晶半導体基板としてのＩｎＰ基板で、そ
の上には多層結晶部１２が形成される。この多層結晶部
１２は、屈折率ｎ、の第１の混晶としてのＩｎＰ層１３
と屈折率ｎ２　（ｎ、４　ｎ２　）の第２の混晶として
のＧａ　Ｉｎ　Ａｓ　Ｐ層１４を一定の厚みのもとに交
互に成長させて形成される。また、その成Ｍ、層の一部
全斜めに研摩またはエツチングすることにより、多層結
晶部１２は一側面が余１而１５となっている。そして、
その斜面１５と多層結晶部１２の上面、さらには前記斜
面１５の下端に連続する基板１１の表面には光導波層１
６が形成される。この光導波層１６はＧａＩｎＡｓＰ＃
からなる。(Example) - An example of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing an embodiment of the present invention. In this diagram, reference numeral 11 denotes an InP substrate as a mixed crystal semiconductor substrate, and a multilayer crystal portion 12 is formed on the InP substrate. This multilayer crystal part 12 includes an InP layer 13 as a first mixed crystal with a refractive index of n.
Ga In As P layers 14 as a second mixed crystal having a refractive index n2 (n, 4 n2 ) are grown alternately to a constant thickness. Furthermore, by polishing or etching a portion of the layer at an angle, one side of the multilayer crystal part 12 is left with a remainder 15. and,
An optical waveguide layer 1 is formed on the surface of the substrate 11 that is continuous with the slope 15, the upper surface of the multilayer crystal part 12, and the lower end of the slope 15.
6 is formed. This optical waveguide layer 16 is made of GaInAsP#
Consisting of

このよりな一実施例においては、多層結晶部１２に斜面
１５を形成することにより、この斜面１５においては／
ＩＴ（折率ｎ、のＩｎＰ層１３と屈折率ｎ、のＧａＩｎ
ＡｓＰ層１４が交互に一定の周期でもって並ぶ。In this more specific embodiment, by forming the slope 15 on the multilayer crystal part 12, the slope 15 can be
IT (InP layer 13 with refractive index n and GaIn layer 13 with refractive index n)
The AsP layers 14 are arranged alternately at a constant period.

ここで、周期は、ＩｎＰ層１３とＧａＩｎＡｓＰ層１４
の厚さに基づいて、第１図と同じＡとなるように設定さ
れる。したがって、この斜面１５を含む部分に形成てれ
た光導波層１６に光が導入されると、その光は、斜面１
５におけるＩｎＰ層１３の屈折率ｎ１トＧａ１ｎＡｓＰ
層１４の屈折率ｎ２が異なるためブラッグ（Ｂｒａｇｇ
　）反射を起し、Ａによって設定される波長の光のみが
導波される。Here, the period is the InP layer 13 and the GaInAsP layer 14.
Based on the thickness of , it is set to be A, which is the same as in FIG. Therefore, when light is introduced into the optical waveguide layer 16 formed in the portion including the slope 15, the light is transmitted to the slope 15.
The refractive index n1 of the InP layer 13 in 5 is Ga1nAsP
Since the refractive index n2 of the layer 14 is different, the Bragg
) reflection occurs, and only light of the wavelength set by A is guided.

そして１以上のよりな一実施例によれば、■実効的に屈
折率の凸凹が深いため良好にブラッグ反射を起こせる、
■幾何学的な凸凹を用いないため光導波層１６の成長時
に熱的損傷などの問題が起きない、■ＩｎＰ層１３とＧ
ａ　ＩｎＡｓ　Ｐ層１４の膜厚は超薄膜にまで制御可能
なことからＡをかなり小さくとれる、という利点がある
。According to one or more preferred embodiments, ① Bragg reflection can be caused well because the refractive index is effectively deep;
■Problems such as thermal damage do not occur during the growth of the optical waveguide layer 16 because no geometrical unevenness is used.■InP layer 13 and G
Since the film thickness of the a InAs P layer 14 can be controlled to an ultra-thin film, there is an advantage that A can be made quite small.

なお、このような一実施例の半導体光素子（光導波路）
は、ＩｎＰ基板１１上にＩｎＰ層１３とＧａＩｎＡｓＰ
層１４とを一定の厚みのもとに交互に成長させて多層結
晶全形成した後、その一部を斜めに研摩またはエツチン
グし、しかる後、光導波層１６を成長させることにより
製造される。In addition, such a semiconductor optical device (optical waveguide) as an example
InP layer 13 and GaInAsP are formed on InP substrate 11.
The optical waveguide layer 16 is manufactured by growing the layers 14 alternately to a constant thickness to completely form a multilayer crystal, then polishing or etching a part of it diagonally, and then growing the optical waveguide layer 16.

第３図はこの発明の半導体光素子の応用例を示す。この
応用例は、一実施例の半導体光素子を半導体レーザに応
用した場合である。したがって、この応用例においては
、第２図の構成に加えて、活性層１７とクラッド層１８
が光導波層１６上に順次成長形成されている。ここで、
各層のエネルギーギャップは（クラッド層）〉（導波層
）〉（活性層）に選ばれる。したがって、電流注入によ
シ活性層１７に発生した光は導波層１６に導入サレ、フ
ラッグ反射によｐ７アグリ・ベローによらずレーデ発振
する。FIG. 3 shows an example of application of the semiconductor optical device of the present invention. This application example is a case where the semiconductor optical device of the embodiment is applied to a semiconductor laser. Therefore, in this application example, in addition to the structure shown in FIG.
are successively grown on the optical waveguide layer 16. here,
The energy gap of each layer is selected as (cladding layer)>(waveguide layer)>(active layer). Therefore, the light generated in the active layer 17 by current injection is introduced into the waveguide layer 16 and causes Radhe oscillation due to flag reflection, regardless of the p7 agri-bellow.

（発明の効果） 以上詳述したようにこの発明の半導体光素子は、多層結
晶を斜めに切ることにより等測的なコルゲーションとし
たから、良好にフラッグ反射を起こせるとともに、光導
波層の成長時に悪影響はなく、しかも屈折率ｎｌ　ｌ　
ｎ、、の周期をかなシ小さくできる。(Effects of the Invention) As detailed above, in the semiconductor optical device of the present invention, the multilayer crystal is cut diagonally to create isometric corrugation, so that it can cause good flag reflection and when the optical waveguide layer grows. There is no adverse effect, and the refractive index nl l
The period of n, , can be made much smaller.

この発明の半導体光素子は縦単一モード半導体レーザな
どに利用できる。The semiconductor optical device of the present invention can be used in longitudinal single mode semiconductor lasers and the like.

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

第１図は従来のコルゲーション型光導波路を示す断面図
、第２図はこの発明の半導体光素子の一実施例を示す断
面図、第３図はこの発明の半導体光素子の応用例を示す
断面図である。 １１・・・ＩｎＰ基板、１２・・・多層結晶部、１３・
・・ＩｎＰ　Ｎｊ、　１４−　ＧａＩｎＡｓＰ層、　１
５　・・・斜面、１６　・・・光導波層。FIG. 1 is a cross-sectional view showing a conventional corrugated optical waveguide, FIG. 2 is a cross-sectional view showing an embodiment of the semiconductor optical device of the present invention, and FIG. 3 is a cross-sectional view showing an application example of the semiconductor optical device of the present invention. It is a diagram. 11... InP substrate, 12... multilayer crystal part, 13...
...InP Nj, 14-GaInAsP layer, 1
5... Slope, 16... Optical waveguide layer.

Claims (1)

【特許請求の範囲】[Claims] 混晶半導体基板と、この基板上に屈折率がｎ、の第１の
混晶と屈折率がｎ２（ｎ、〜ｎｚ）の第２の混晶を一定
の厚みのもとに交互に成長して形成され、所定の側面は
、屈折率ｎｌ＊ｎ２の第１．第２の混晶が交互に一定の
周期でもって並ぶ斜面に形成された多層結晶部と、この
多層結晶部の少なくとも前記斜面に形成された先導波層
とを具備してなる半導体光素子。A mixed crystal semiconductor substrate, and on this substrate, a first mixed crystal with a refractive index of n and a second mixed crystal with a refractive index of n2 (n, ~ nz) are grown alternately at a constant thickness. The predetermined side surface has a first . A semiconductor optical device comprising: a multilayer crystal part formed on a slope in which second mixed crystals are arranged alternately at a constant period; and a waveguide layer formed on at least the slope of the multilayer crystal part.