A light-emitting element includes a mesa structure in which a first compound semiconductor layer of a first conductivity type, an active layer, and a second compound semiconductor layer of a second conductivity type are disposed in that order, wherein at least one of the first compound semiconductor layer and the second compound semiconductor layer has a current constriction region surrounded by an insulation region extending inward from a sidewall portion of the mesa structure; a wall structure disposed so as to surround the mesa structure; at least one bridge structure connecting the mesa structure and the wall structure, the wall structure and the bridge structure each having the same layer structure as the portion of the mesa structure in which the insulation region is provided; a first electrode; and a second electrode disposed on a top face of the wall structure.

A vertical cavity surface-emitting laser including: a substrate having a main surface; and a post structure mounted on the main surface. The post structure includes an active layer and a carrier confinement structure. The carrier confinement structure includes a first region and a second region having a higher resistivity than the first region. The first region has an edge, and a first to a third reference line segments. A first length of the first reference line segment is longest among lengths of line segments joining any two points on the edge and extending in a direction of the III-V group semiconductor. The first length is greater than a sum of a second length of the second reference line segment and a third length of the third reference line segment. The third length is smaller than the second length and is zero or more.

A VCSEL array includes a plurality of VCSEL elements arranged in a programmed pattern defining a center portion and a peripheral edge portion. The interval distances between the VCSEL elements in the vicinity of the center portion and/or at the center portion are greater than the interval distances between the VCSEL elements close to the peripheral edge portion, such that the VCSEL array has a uniform power output.

There is provided a semiconductor laser including: a first mirror layer; a second mirror layer; an active layer; a current confinement layer; a first region including a plurality of first oxidized layers; and a second region including a plurality of second oxidized layers, in which, in a plan view, the laminated body includes a first part including the first region and the second region, a second part including the first region and the second region, and a third part disposed between the first part and the second part and resonating light generated in the active layer, the third part includes a fourth part including the first region and the second region and having a first groove, a fifth part including the first region and the second region and having a second groove, and a sixth part disposed between the fourth part and the fifth part and sandwiched between the first part and the second part, in a plan view.

A semiconductor laser including: a first mirror layer; a second mirror layer; an active layer, a current confinement layer, a first region, and a second region, in which the first mirror layer, the second mirror layer, the active layer, the current confinement layer, the first region, and the second region constitute a laminated body, the first region and the second region constitute an oxidized region of the laminated body, in a plan view, the laminated body includes a first part, a second part, and a third part disposed between the first part and the second part and resonating light generated in the active layer, and in a plan view, at least at a part of the third part, W1>W3 and W2>W3, W1 is a width of the oxidized region of the first part, W2 is a width of the oxidized region of the second part, and W.sub.3 is a width of the oxidized region of the third part.

A VCSEL can include: an elliptical oxide aperture in an oxidized region that is located between an active region and an emission surface, the elliptical aperture having a short radius and a long radius with a radius ratio (short radius)/(long radius) being between 0.6 and 0.8, the VCSEL having a relative intensity noise (RIN) of less than 140 dB/Hz. The VCSEL can include an elliptical emission aperture having the same dimensions of the elliptical oxide aperture. The VCSEL can include an elliptical contact having an elliptical contact aperture therein, the elliptical contact being around the elliptical emission aperture. The elliptical contact can be C-shaped. The VCSEL can include one or more trenches lateral of the oxidized region, the one or more trenches forming an elliptical shape, wherein the oxidized region has an elliptical shape. The one or more trenches can be trapezoidal shaped trenches.

A VCSEL device includes a substrate and a first DBR structure disposed on the substrate. The VCSEL device further includes a cathode contact disposed on a top surface of the first DBR structure. In addition, the VCSEL device includes a VCSEL mesa that is disposed on the top surface of the first DBR structure. The VCSEL mesa includes a quantum well, a non-circularly-shaped oxide aperture region disposed above the quantum well, and a second DBR structure disposed above the non-circularly-shaped oxide aperture region. In addition, the VCSEL mesa includes a selective polarization structure disposed above the second DBR structure and an anode contact disposed above the selective polarization structure.

A non-planarized VCSEL can include: a blocking region over or under an active region, the blocking region having a first thickness; one or more conductive channel cores in the blocking region, the one or more conductive channel cores having a second thickness that is larger than the first thickness, wherein the blocking region is defined by having an implant and the one or more conductive channel cores are devoid of the implant, wherein the blocking region is lateral the one or more conductive channel cores, the blocking region and one or more conductive channel cores being an isolation region; and a non-planarized semiconductor region of one or more non-planarized semiconductor layers over the isolation region. The VCSEL can include a planarized bottom mirror region below the active region and a non-planarized top mirror region above the isolation region, or a non-planarized bottom mirror region below the active region.

An etched planarized VCSEL includes: an active region; a blocking region over the active region, and defining apertures therein; and conductive channel cores in the apertures, wherein the conductive channel cores and blocking region form an isolation region. A method of making the VCSEL includes: forming the active region; forming the blocking region over the active region; etching the apertures in the blocking region; and forming the conductive channel cores in the apertures of the blocking region. Another etched planarized VCSEL includes: an active region; a conductive region over the active region, and defining apertures therein; and blocking cores in the apertures, wherein the blocking cores and conductive region form an isolation region. A method of making the VCSEL includes: forming the active region; forming the conductive region over the active region; etching the apertures in the conductive region; and forming the blocking cores in the apertures of the conductive region.

A semiconductor optical amplifier includes a conductive region that is provided on a substrate and allows light transmission, and a nonconductive region that is provided around the conductive region and prohibits light transmission. The conductive region includes a first region including a light-coupling portion to which light from an external light-source unit is coupled, and a second region having a narrower width than the first region and connected to the first region through a connecting portion, the second region including a light-amplifying portion amplifying the light from the light-coupling portion by propagating the light in a predetermined propagating direction along a surface of the substrate, the light-amplifying portion outputting the amplified light in a direction intersecting the surface of the substrate. Seen in a direction perpendicular to the surface of the substrate, the semiconductor optical amplifier includes a portion where a width of the conductive region is continuously reduced from the first region to the second region.