A semiconductor integrated optical device includes a waveguide mesa having a first multilayer including a first core layer, a second multilayer including a second core layer, and a butt joint interface between the first core layer and the second core layer; a support having first to third regions; and a buried semiconductor region provided on the support. The first multilayer has a first mesa width on the first region. The second multilayer has a second mesa width on the second region. On the third region, the second multilayer has a waveguide portion having a third mesa width smaller than the first and the second mesa widths. The second core layer has a waveguide core thickness on the second region. In the waveguide portion, the second core layer has a core portion having a thickness different from the waveguide core thickness at a position away from the butt-joint interface.

A semiconductor optical device is provided with a semiconductor substrate that has a length and width, a laser section that is provided on the semiconductor substrate and includes an active layer and an optical waveguide section that is provided adjacent to the laser section on the semiconductor substrate and is joined to the laser section. The optical waveguide section includes a core layer that is connected to an end portion of the active layer, and a pair of cladding layers between which the core layer is sandwiched and emits, from an emission end surface, light incident from the joining interface between the optical waveguide section and the laser section. The semiconductor optical device may be also provided with a reflection suppression layer that is provided on the upper surface of the optical waveguide section.

A semiconductor device includes a substrate, a semiconductor laser part formed on the substrate and having an active layer with an uniform composition and a first ridge structure, and an adjacent part formed on the substrate, having a core layer with an uniform composition and a second ridge structure, and being an optical modulator or an optical waveguide which is in contact with the semiconductor laser part, wherein the first ridge structure is largest in width at a first contact part which is in contact with the second ridge structure, and the second ridge structure is largest in width at a second contact part which is in contact with the first ridge structure.

A semiconductor integrated optical device includes a waveguide mesa having a first multilayer including a first core layer, a second multilayer including a second core layer, and a butt joint interface between the first core layer and the second core layer; a support having first to third regions; and a buried semiconductor region provided on the support. The first multilayer has a first mesa width on the first region. The second multilayer has a second mesa width on the second region. On the third region, the second multilayer has a waveguide portion having a third mesa width smaller than the first and the second mesa widths. The second core layer has a waveguide core thickness on the second region. In the waveguide portion, the second core layer has a core portion having a thickness different from the waveguide core thickness at a position away from the butt-joint interface.

A manufacturing method for an optical semiconductor device includes: forming a first semiconductor layer; forming a first mask pattern on the first semiconductor layer in a first area where an electro absorption type modulator is formed; forming an evenness along the first direction on the first semiconductor layer; forming a second semiconductor layer on the unevenness; and forming an optical waveguide layer on the second semiconductor layer. The first mask pattern includes a first pattern in the first area and a second pattern in a second area where a DFB laser is formed, the first pattern including a first opening pattern and a first cover pattern, and the second pattern including a second opening pattern and a second cover pattern, and a ratio of the first opening pattern to the first cover pattern is different from that of the second opening pattern to the second cover pattern.

The optical mode of a photonic device is coupled between a first region made of a semiconducting material, and a second region made of a dielectric material. Photons are generated within the first region, while the optical mode is predominantly stored within the second region. The thickness of the first region and its width are controlled to determine its effective refractive index, enabling control of the optical mode.

A semiconductor device includes a substrate, a semiconductor laser part formed on the substrate and having an active layer with an uniform composition and a first ridge structure, and an adjacent part formed on the substrate, having a core layer with an uniform composition and a second ridge structure, and being an optical modulator or an optical waveguide which is in contact with the semiconductor laser part, wherein the first ridge structure is largest in width at a first contact part which is in contact with the second ridge structure, and the second ridge structure is largest in width at a second contact part which is in contact with the first ridge structure.

The optical mode of a photonic device is coupled between a first region made of a semiconducting material, and a second region made of a dielectric material. Photons are generated within the first region, while the optical mode is predominantly stored within the second region. The thickness of the first region and its width are controlled to determine its effective refractive index, enabling control of the optical mode.

In an embodiment a method for manufacturing a light-emitting semiconductor chip includes providing a substrate having a main surface with at least one recess, the main surface having a main extension plane along the longitudinal direction and along a transversal direction perpendicular to the longitudinal direction, wherein the substrate has pre-patterning trenches formed along the transversal direction between chip regions and extending along the longitudinal direction, growing the semiconductor layer sequence on the main surface with the at least one recess and forming at least one facet aligned along the transversal direction in the semiconductor layer sequence by an etching process, wherein the facet has a distance of less than or equal to 50 ?m from the at least one recess in at least one direction parallel to the main extension plane of the main surface.

A fiber optic cable including a first end and a second end, a core adapted to receive and transmit an optical signal and a cladding layer surrounding the core is disclosed. The fiber optic cable may include a ratio of an outside diameter of the cladding layer to a diameter of the core that decreases from the first end to the second end while the diameter of the core remains substantially uniform. The fiber optic cable may include a first portion of the cladding layer and a second portion of the cladding layer. A uniform outside diameter of the second portion may be less than a uniform outside diameter of the first portion. The fiber optic cable may further include a third portion of the cladding layer. A uniform outside diameter of the third portion may be less than a uniform outside diameter of the second portion.