A buried semiconductor optical device comprises a semiconductor substrate; a mesa-stripe portion including a multi-quantum well layer on the semiconductor substrate; a buried layer consisting of a first portion and a second portion, the first portion covering one side of the mesa-stripe portion, the second portion covering the other side of the mesa-stripe portion, and the first portion and the second portion covering a surface of the semiconductor substrate; and an electrode configured to cause an electric current to flow through the mesa-stripe portion, the buried layer comprising, from the surface, a first, second, and third sublayer, the first and third sublayer each consisting of semi-insulating InP, the first sublayer and the second sublayer forming a pair structure, the second sublayer being located above the multi-quantum well layer, and the second sublayer consisting of one or more layers selected from InGaAs, InAlAs, InGaAlAs, InGaAsP, and InAlAsP.

A semiconductor device according to the present disclosure includes a main part that includes a semiconductor substrate, a first cladding layer provided on the semiconductor substrate, an active layer provided on the first cladding layer, and a second cladding layer provided on the active layer, and in which a flat part and a mesa part are formed, the mesa part including the active layer and a first embedded layer covering a top surface of the flat part and a side surface of the mesa part, wherein the first embedded layer has a projecting part on a top surface of a portion provided in a region within a height of the mesa part from a boundary between the mesa part and the flat part in the top surface of the flat part.

A semiconductor laser element includes a semiconductor laminated structure that has a substrate, an n type cladding layer disposed at a front surface side of the substrate, an active layer disposed at an opposite side of the n type cladding layer to the substrate, and p type cladding layers disposed at an opposite side of the active layer to the n type cladding layer. The active layer includes a quantum well layer having a tensile strain for generating TM mode oscillation and the n type cladding layer and the p type cladding layers are respectively constituted of AlGaAs layers.

What is provided are: an active-layer ridge which is composed of an n-type cladding layer, an active layer, a first p-type cladding layer and a second n-type blocking layer that are stacked in this order on an n-type InP substrate, and which is formed to project from a position lower than the active layer; burying layers by which both side portions of the active-layer ridge are buried up to a position higher than the active layer; first n-type blocking layers which are each stacked on a front-surface side of each of the burying layers, to be placed on the both sides of the ridge; and a second p-type cladding layer by which an end portion of the active-layer ridge and the first n-type blocking layers are buried thereunder; wherein a current narrowing window for allowing a hole current to pass therethrough is provided in and at a center of the second n-type blocking layer placed at a top of the active-layer ridge.

A non-refrigerated tunable semiconductor laser based on a multi-wavelength array includes a thermistor, a tunable laser array, a multiplexing structure, an optical amplifier, an optical splitter, an optical detector, and a main controller. The tunable laser array include a plurality of laser units with different wavelengths, and the tunable laser array is connected to the optical splitter and the main controller through the multiplexing structure and the optical amplifier in sequence. When the laser is influenced by the external environment temperature, the value of the influence caused by the external environment temperature is calculated, and drive currents of the tunable laser array and the optical amplifier are adjusted and controlled respectively according to the calculation result, so as to achieve the purpose that parameters of the final output light are consistent with parameters of the theoretical light.

A light emitting device includes a substrate, a buffer layer, a first active layer, and a plurality of mesa regions. A portion of the first active layer includes a first electrical polarity. The plurality of mesa regions includes at least a portion of the first active layer, a light emitting region on the portion of the first active layer, and a second active layer on the light emitting region. A portion of the second active layer includes a second electrical polarity. The light emitting region is configured to emit light which has a target wavelength between 200 nm to 300 nm. A thickness of the light emitting region is a multiple of the target wavelength, and a dimension of the light emitting region parallel to the substrate is smaller than 10 times the target wavelength, such that the emitted light is confined to fewer than 10 transverse modes.

A method of manufacturing a surface emitting laser according to an embodiment of the present disclosure includes the following two steps: (1) a step of forming a semiconductor stacked structure on a substrate, the semiconductor stacked structure including an active layer, a first DBR layer of a first electrical conduction type, and a second DBR layer of a second electrical conduction type, the first DBR layer and the second DBR layer sandwiching the active layer, the second electrical conduction type being different from the first electrical conduction type; and (2) a step of forming a mesa section at a portion on the second DBR layer side in the semiconductor stacked structure and then forming an annular diffusion region of the first electrical conduction type at an outer edge of the mesa section by impurity diffusion from a side surface of the mesa section, the mesa section including the second DBR layer, the mesa section not including the active layer.

A method of producing an ultraviolet laser diode with a low oscillation threshold current density includes stacking a first cladding layer, a light-emitting layer, and a second cladding layer on a substrate in this order to form a nitride semiconductor laminate (step S101), etching at least a portion of the nitride semiconductor laminate to form a mesa structure and setting the ratio between the length of the resonator end faces and the length of the side surfaces of the mesa structure in plan view between 1:5 and 1:500 (step S102), disposing first conductive material on a portion of a first area and applying heat treatment of 400° C. or higher to form a first electrode (step S103), and disposing a second conductive material in an area on the second cladding layer, at a distance of 5 um or more from the side surfaces, to form a second electrode (step S104).

An optical semiconductor device is provided with: a mesa in which a first conductivity type cladding layer, an active layer, and a second conductivity type first cladding layer having a second conductivity type are sequentially laminated on a surface of a first conductivity type substrate; a buried layer that buries both sides of the mesa with a top of the mesa being exposed; and a second conductivity type second cladding layer that buries the buried layer and the top of the mesa exposed from the buried layer, wherein the buried layer includes a layer doped with a semi-insulating material, and a boundary between the second conductivity type first cladding layer and the buried layer is inclined so that a width of the second conductivity-type first cladding layer becomes narrower toward the top of the mesa.

To provide a Fabry-Perot semiconductor laser diode obtained through a step of forming a mirror facet using an etching technology, in which the threshold current density for laser oscillation is reduced.

A method for manufacturing a semiconductor laser diode includes a step of forming a plurality of semiconductor laser diodes on a substrate, and then dividing the substrate into each semiconductor laser diode. The method includes a step of forming a laminate containing a first semiconductor layer 21, a waveguide layer (first guide layer 22, light emitting layer 23, second guide layer 24), and a second semiconductor layer 25 in this order on a substrate 1, a step of etching the laminate to separate the laminate into a portion serving as a resonance region and the other portion, an electrode layer forming step of forming a layer 51 serving as a second electrode on the second semiconductor layer 25 of the laminate to between the mirror facet 200 of the resonance region and a position where the substrate 1 is divided in the dividing step, and, after the electrode layer forming step, an etching step of simultaneously or sequentially performing the removal of a portion 51a formed at a position on the outer side relative to the mirror facet 200 of the layer serving as the second electrode and the formation the mirror facet 200.