The invention relates to an edge emitting laser diode comprising a semiconductor layer stack whose growth direction defines a vertical direction, and wherein the semiconductor layer stack comprises an active layer and a waveguide layer. A thermal stress element is arranged in at least indirect contact with the semiconductor layer stack, the thermal stress element being configured to generate a thermally induced mechanical stress in the waveguide layer that counteracts the formation of a thermal lens.

An optical resonance structure is provided. For example, an optical resonator may operate based on a single-material double-layer HCG resonance structure. The optical resonator includes a first member and a second member. Each of the first member and the second member has a high contrast grating (HCG) structure, and a refractive index of the first member and a refractive index of the second member are the same.

A semiconductor optical integrated device is a semiconductor optical integrated device in which a first optical element, a monitoring light waveguide and a second optical element, through which light propagates, are formed on a common semiconductor substrate; wherein the monitoring light waveguide is joined to the first optical element, and the second optical element is joined to the monitoring light waveguide. The monitoring light waveguide includes a light scattering portion for scattering a part of the light, which is composed of a combination of light waveguides having different mode field diameters or having different centers of mode field diameters; and a light detector for receiving scattered light scattered by the light scattering portion, is placed on an outer periphery of the monitoring light waveguide, or on a back surface of the semiconductor substrate on its side opposite to that facing the light scattering portion.

A semiconductor laser device of the present disclosure includes: a first-conductivity-type cladding layer, a first-conductivity-type-side optical guide layer, an active layer, a second-conductivity-type-side optical guide layer, a second-conductivity-type cladding layer, and a second-conductivity-type contact layer laminated above a semiconductor substrate; a resonator having a front end surface and a rear end surface; and a ridge region for guiding a laser beam between the front and rear end surfaces. The ridge region is composed of a ridge inner region in which an effective refractive index is n.sub.a.sup.i, and ridge outer regions which are provided on both sides of the ridge inner region and in which an effective refractive index is n.sub.a.sup.o, the ridge outer regions having current non-injection structures. A ridge outer region width W.sub.o is greater than a distance from a lower end of each current non-injection structure to the active layer.

A semiconductor laser element includes: a substrate having a projection at an upper face thereof; a first semiconductor layer; a light emission layer; a second semiconductor layer; and a low refractive index part having a refractive index lower than that of the first semiconductor layer. The second semiconductor layer has a ridge part for guiding laser light generated in the light emission layer. An angle between a side face of the ridge part and the waveguiding direction is larger than a limit angle defined by an effective refractive index on each of an inner side of the ridge part and an outer side of the ridge part. The low refractive index part is disposed between an active layer of the light emission layer and the projection of the substrate, and on the outer side of the side face at least where the width of the ridge part is small.

An intermediate ultraviolet laser diode device includes a gallium and nitrogen containing substrate member comprising a surface region, a release material overlying the surface region, an n-type gallium and nitrogen containing material; an active region overlying the n-type gallium and nitrogen containing material; a p-type gallium and nitrogen containing material; a first transparent conductive oxide material overlying the p-type gallium and nitrogen containing material; and an interface region overlying the first transparent conductive oxide material.

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 optical device that achieves both of heat dissipation and light confinement and permits efficient current injection or application of an electric field is implemented. The semiconductor optical device includes: a core layer including an active region (1) made of a compound semiconductor; two cladding layers (5, 6) injecting current into the core layer; and a third cladding layer (4) made of a material having a larger thermal conductivity, a smaller refractive index, and a larger band gap than a material for any of the core layer and the two cladding layers.

The present embodiment relates to a light-emitting device or the like having a structure capable of reducing one power of ±1st-order light with respect to the other power. The light-emitting device includes a substrate, a light-emitting portion, and a phase modulation layer including a base layer and a plurality of modified refractive index regions. Each of the plurality of modified refractive index regions has a three-dimensional shape defined by a first surface facing the substrate, a second surface positioned on a side opposite to the substrate with respect to the first surface, and a side surface. In the three-dimensional shape, at least one of the first surface, the second surface, and the side surface has a portion inclined with respect to a main surface.

A semiconductor optical device that achieves both of heat dissipation and light confinement and permits efficient current injection or application of an electric field is implemented. The semiconductor optical device includes: a core layer including an active region (1) made of a compound semiconductor; two cladding layers (5, 6) injecting current into the core layer; and a third cladding layer (4) made of a material having a larger thermal conductivity, a smaller refractive index, and a larger band gap than a material for any of the core layer and the two cladding layers.