Integrated optical isolator

An integrated optical isolator, wherein a semiconductor waveguide layer is grown on a compound semiconductor substrate, a semiconductor laser is formed on a one-side part of the semiconductor waveguide layer, and an optical isolator is formed on an other-side part,

• wherein a light-emitting waveguide is formed for a light-emitting output in the semiconductor laser portion of the semiconductor waveguide layer, a laser current injection electrode to inject a current into the light-emitting waveguide is formed on an upper portion of the light-emitting waveguide, semiconductor clad layers are arranged on both sides of the laser current injection electrode, and the semiconductor waveguide layer at a background propagation light output waveguide output end under the semiconductor clad layer is caused to serve as a terminal absorbing layer functioning as a light-absorbing layer.

An integrated optical isolator, wherein a semiconductor waveguide layer is grown on a compound semiconductor substrate, a semiconductor laser is formed on a one-side part of the semiconductor waveguide layer, and an optical isolator is formed on an other-side part,

• wherein a semiconductor clad layer is laminated on the semiconductor waveguide layer of the semiconductor laser portion, an insulating layer is arranged in a region except for a part serving as a laser light-emitting region on the semiconductor clad layer, a laser current injection electrode is arranged on the insulating layer and the semiconductor clad layer in a region where the insulating layer is not laminated, and the semiconductor waveguide layer under the insulating layer is caused to serve as a terminal absorbing layer acting as a light-absorbing layer.

An integrated optical isolator, wherein a semiconductor waveguide layer is laminated on a compound semiconductor substrate, a semiconductor laser is formed on a one-side part of the semiconductor waveguide layer, and an optical isolator is formed on an other-side part,

• wherein a semiconductor laser is arranged on the semiconductor waveguide layer in the semiconductor laser portion, a laser current injection electrode is arranged on a region serving as an internal laser active layer of the semiconductor waveguide layer, the semiconductor waveguide layer except for the laser active layer serves as a terminal absorbing layer acting as a light-absorbing layer, an isolation portion is arranged between the laser active layer and the terminal absorbing layer to prevent an injection current from flowing into the terminal absorbing layer, and a weak leakage light from the terminal absorbing layer to the laser active layer is further attenuated.