Matsushita Electric Industrial Co., Ltd.

Matsushita Electronics Corporation

Hiroki Naito

Masahiro Kume

Toru Takayama

Kunio Itoh

Hirokazu Shimizu

Issei Ohta

Hideyuki Sugiura

On an n-type semiconductor substrate, a buffer layer and a cladding layer are formed. On the cladding layer, an active layer made of Ga.sub.1-X Al.sub.X As is formed. On the active layer, an n-type first optical guiding layer made of Ga.sub.1-Y1 Al.sub.Y1 As is formed, and on the first optical guiding layer, an n-type second optical guiding layer made of Ga.sub.1-Y2 Al.sub.Y2 As is formed in stripe. On the first optical guiding layer and the second optical guiding layer, an n-type cladding layer made of Ga.sub.1-Y3 Al.sub.Y3 As is formed. The interface resistance between the first optical guiding layer and the cladding layer is larger than both the interface resistance between the first optical guiding layer and the second optical guiding layer and the interface resistance between the second optical guiding layer and the cladding layer. Between X, Y1, Y2, and Y3 of each AlAs mole fraction of the active layer, first and second optical guiding layers, and cladding layer, the relationships of Y3&gt;Y2 and Y1&gt;X.gtoreq.0 are satisfied.

Method for forming semiconductor laser device

Semiconductor laser device

A semiconductor laser device of low operating current and low noise for the 780 nm band to be used as the light source for an optical disc and its fabrication method. The device comprises: a certain conduction type Ga.sub.1-Y1 Al.sub.Y1 As first light guide layer, a Ga.sub.1-Y2 Al.sub.Y2 As second light guide layer of said certain conduction type, or an In.sub.0.5 Ga.sub.0.5 P or an In.sub.0.5 (GaAl).sub.0.5 P or an InGaAsP second light guide layer, successively formed one upon another at least in one side of the principal plane of an active layer; an opposite conduction type Ga.sub.1-Z Al.sub.Z As current blocking layer formed on the second light guide layer and provided with a stripe-like window; and a Ga.sub.1-Y3 Al.sub.Y3 As cladding layer of the same conduction type a said light guide layers formed on said stripe-like window, wherein relations of Z&gt;Y3&gt;Y2 and Y1&gt;Y2 are established among Y1, Y2 Y3 and Z that define the AlAs mole-fractions.

Semiconductor laser device fabrication method

A semiconductor laser device suitable as a light source for an optical disk may be operated at a low operating current with low noise for the 780 nm band. The device comprises: a certain conduction type Ga.sub.1-Y1 Al.sub.Y1 As first light guide layer, a Ga.sub.1-Y2 Al.sub.Y2 As second light guide layer of said certain conduction type, or an In.sub.0.5 Ga.sub.0.5 P or an In.sub.0.5 (GaAl).sub.0.5 P or an InGaAsP second light guide layer, successively formed one upon another at least in one side of the principal plane of an active layer; an opposite conduction type Ga.sub.1-Z Al.sub.Z As current blocking layer formed on the second light guide layer and provided with a stripe-like window; and a Ga.sub.1-Y3 Al.sub.Y3 As cladding layer of the same conduction type as the light guide layers formed on the stripe-like window. The relations of Z&gt;Y3&gt;Y2 and Y1&gt;Y2 define the AlAs mole fractions.

Low operating current and low noise semiconductor laser device for

Growing community of inventors

Suita, Japan

Hiroki Naito