Tokyo Institute of Technology

Kokusai Denshin Denwa Kabushiki Kaisha

Other

Sumitomo Electric Industries, Limited

Research Development Corporation of Japan

Yasuharu Suematsu

Mitsuo Takahashi

Chuichi Ota

Hideaki Nishizawa

Yoshio Itaya

Shigeyuki Akiba

Takaya Yamamoto

Kazuo Sakai

Kenichi Iga

Masanobu Kodaira

Shigehisa Arai

Disclosed are a distributed Bragg reflector type semiconductor laser and a method of manufacturing such a laser a high yields, in which the upper surface of an active waveguide is covered by an external waveguide, the external waveguide at side portions thereof, the external waveguide is coupled with the edge surfaces of the active waveguide without any gap remaining, and the coupling ratio of the active waveguide and external waveguide is high.

Method of manufacturing a distributed brass reflector type semiconductor

Disclosed are a distributed Bragg reflector type semiconductor laser and a method of manufacturing such a laser a high yields, in which the upper surface of an active waveguide is covered by an external waveguide, the external waveguide is disposed on the same surface as the active waveguide at side portions thereof, the external waveguide is coupled with the edge surfaces of the active waveguide without any gap remaining, and the coupling ratio of the active waveguide and external waveguide is high.

Distributed bragg reflector type semiconductor laser

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

A multi-hetero-structure waveguide type optical integrated circuit is provided wherein a thin-film element such as a semiconductor laser is coupled through a directional coupler to a waveguide having a small transmission loss.

Multi-hetero-structure waveguide type optical integrated circuitry

Growing community of inventors

Kawasaki, Japan

Yasuharu Suematsu