Kokusai Denshin Denwa Kabushiki Kaisha

Yoshio Itaya

Chuichi Ota

Yasuharu Suematsu

Shigeyuki Akiba

Takaya Yamamoto

Kazuo Sakai

Kenichi Iga

Shigehisa Arai

Masanobu Kodaira

A semiconductor laser having a multi-layer film which is inclusive of an active layer and formed on an InP substrate, in which at least one layer adjacent to the active layer is formed of a material which is a composition having a larger band gap than InP and whose component ratio is so selected as to match with the lattice constant of InP, thereby to ensure that minority carriers injected into the active layer efficiently contribute to laser operation. The material has a composition including at least three elements in addition to InP.

Semiconductor laser

A semiconductor laser formed on an InP substrate to have a hetero structure comprising a plurality of In.sub.1-x Ga.sub.x`As.sub.y P.sub.1-y (0.42y.ltoreq.x.ltoreq.0.5y,0.ltoreq.y.ltoreq.1) layers which are lattice-matched with InP, in which a light emitting layer included in the layers and having a forbidden band width larger than 0.6 eV but smaller than 0.9 eV at room temperature is sandwiched between two InP layers on the InP substrate, and in which there is provided between the light emitting layer and the InP layer grown thereon at least one buffer layer having a forbidden band width larger than the forbidden band width of the light emitting layer but smaller than the forbidden band width of InP. The forbidden band width of the buffer layer at room temperature may be larger than 0.8 eV but smaller than 1.0 eV.

Semiconductor laser with buffer layer

Growing community of inventors

Tokyo, Japan

Yoshio Itaya