A laser diode chip includes a removable substrate, a first semiconductor layer disposed on the removable substrate, an emitting layer disposed on one part of the first semiconductor layer, a second semiconductor layer disposed on the emitting layer and forming a ridge mesa, a current conducting layer disposed on another part of the first semiconductor layer, a patterned insulating layer covering the second semiconductor layer and the current conducting layer and including a first zone and a second zone which respectively expose a part of the current conducting layer and a part of the second semiconductor layer, a first electrode and a second electrode respectively disposed on the first zone and the second zone. A projection of the ridge mesa projected to the removable substrate covers a part of projections of the first electrode and the second electrode projected to the removable substrate.

The present invention provides one or more injection-lockable whistle-geometry semiconductor ring lasers, which may be cascaded, that are integrated on a common silicon-on-insulator (SOI) substrate with a single-frequency semiconductor master laser, wherein the light output from the semiconductor master laser is used to injection-lock the first of the semiconductor ring lasers. The ring lasers can be operated in strongly injection-locked mode, while at least one of them is subjected to direct injection current modulation.

A method for manufacturing an optical semiconductor device having a ridge stripe configuration containing an active layer and current blocking layers which embed both sides of the ridge stripe configuration, comprises steps of forming a mask of an insulating film on a surface of a semiconductor layer containing an active layer, forming a ridge stripe configuration by etching a semiconductor layer using gas containing SiCl.sub.4, removing an oxide layer with regard to a Si based residue which is attached on a surface which is etched of the ridge stripe configuration which is formed and removing a Si based residue whose oxide layer is removed.

A light emitting component includes plural transfer elements, plural setting thyristors, and plural light emitting elements. The transfer elements are configured to be sequentially brought into an ON state. The setting thyristors are connected to the transfer elements, respectively. The setting thyristors are configured to be brought into a state where the setting thyristors are capable of changing to the ON state when the transfer elements are brought into the ON state. The light emitting elements are stacked on the setting thyristors through tunnel junctions, respectively. The light emitting elements are configured to emit light of increase a light emission amount when the setting thyristors are brought into the ON state.

A semiconductor laser in a ridge waveguide structure includes: a semiconductor substrate; a lower cladding layer which is formed on the semiconductor substrate; an active layer and a semiconductor layer which are in parallel on the lower cladding layer and are connected with each other; a first upper cladding layer locally aligned above the active layer; a second upper cladding layer locally aligned above the semiconductor layer; and a third upper cladding layer locally aligned above the active layer to confine light which is guided in the active layer, wherein the semiconductor layer has a band gap which is larger than that of the active layer. According to this constitution, an optical semiconductor device with high reliability in which the ridge waveguide structure whose manufacturing is relatively easy is applied, and current diffusion and electrical crosstalk between lasers in the ridge waveguide structure are suppressed is enabled.

A semiconductor laser may include a substrate, an active region, and an electron stopper layer. The electron stopper layer may include an aluminum gallium indium arsenide phosphide alloy. The aluminum gallium indium arsenide phosphide alloy may have an Al.sub.xGa.sub.yIn.sub.(1-x-y)As.sub.zP.sub.(1-z) composition.

Provided is a semiconductor laser including: a core layer having an active layer and a diffraction grating layer optically coupled to the active layer; and paired clad layers arranged sandwiching the core layer, and formed with a waveguide along the core layer, and the semiconductor laser includes: a flat layer provided continuously with the diffraction grating layer along the waveguide; and a temperature control mechanism for controlling the temperature of the flat layer to a temperature different from that of the diffraction grating layer.

An optoelectronic component includes a layer structure including an active zone that generates electromagnetic radiation and is arranged in a plane, wherein the layer structure includes a top side and four side faces, first and third side faces are arranged opposite one another, second and fourth side faces are arranged opposite one another, a strip-shaped ridge structure is arranged on the top side of the layer structure and extends between the first side face and the third side face, the first side face constitutes an emission face for electromagnetic radiation, wherein a first recess is introduced into the top side of the layer structure laterally alongside the ridge structure, a second recess is introduced into the first recess, the second recess extends as far as the second side face, and at least one third recess is introduced into a base face of the first recess laterally alongside the ridge structure.

A laser includes a substrate, first and second claddings, a gain medium, and multiple supports. The first cladding is spaced apart from the substrate by an air gap. A thickness of the first cladding in a vertical direction is in a range from 0.05-0.15 micrometers. The gain medium is disposed on the first cladding opposite the air gap. The second cladding is disposed on the gain medium opposite the first cladding. A thickness of the second cladding in the vertical direction is in a range from 0.05-0.15 micrometers. The supports are coupled to each of the substrate, the first cladding, the gain medium, and the second cladding to retain the first cladding, the gain medium, and the second cladding spaced apart from the substrate.

An optical semiconductor device includes a substrate, a semiconductor multilayer which is formed on the substrate, and includes an optical functional layer, an insulating film formed on the semiconductor multilayer, and an electrode formed on a part of the insulating film. The insulating film covers the semiconductor multilayer except for a region in which the semiconductor multilayer and the electrode are electrically connected to each other. At least a part of a region of the insulating film that is overlapped with the electrode is thinner than a region of the insulating film that is not overlapped with the electrode.