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.

An optoelectronic device includes a semiconductor substrate with a first set of epitaxial layers formed on an area of the substrate defining a lower distributed Bragg-reflector (DBR) stack. A second set of epitaxial layers formed over the first set defines a quantum well structure, and a third set of epitaxial layers, formed over the second set, defines an upper DBR stack. At least the third set of epitaxial layers is contained in a mesa having sides that are perpendicular to the epitaxial layers. A dielectric coating extends over the sides of at least a part of the mesa that contains the third set of epitaxial layers. Electrodes are coupled to the epitaxial layers so as to apply an excitation current to the quantum well structure.

Provided is a light source device, including: a base member; a semiconductor laser disposed on the base member; a lateral wall portion formed so as to surround the semiconductor laser; a light-transmissive lid covering a gap surrounded by the base member and the lateral wall portion; and a connection member that airtightly connects an upper surface of the lateral wall portion and a lower surface of the lid over an entire perimeter of the lateral wall portion. The lateral wall portion has a reflecting surface which is an inside surface connected to an upper surface, the reflecting surface being inclined so that light emitted from the semiconductor laser is reflected toward the lid. A dielectric film is continuously formed on the reflecting surface and the upper surface. A height of the connection member is greater than a height of the dielectric film formed on the upper surface.

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 nitride semiconductor light-emitting element includes: an N-type cladding layer; an N-side guide layer disposed above the N-type cladding layer; an active layer disposed above the N-side guide layer; a first P-side guide layer disposed above the active layer; an electron barrier layer disposed above the first P-side guide layer; a second P-side guide layer disposed above the electron barrier layer; and a P-type cladding layer disposed above the second P-side guide layer. An average band gap energy of the second P-side guide layer is greater than an average band gap energy of the first P-side guide layer. An average band gap energy of the P-type cladding layer is less than an average band gap energy of the electron barrier layer.

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 nitride semiconductor light emitting device includes a first coat film of aluminum nitride or aluminum oxynitride formed at a light emitting portion and a second coat film of aluminum oxide formed on the first coat film. The thickness of the second coat film is at least 80 nm and at most 1000 nm. Here, the thickness of the first coat film is preferably at least 6 nm and at most 200 nm.

A nitride semiconductor light emitting device includes a first coat film of aluminum nitride or aluminum oxynitride formed at a light emitting portion and a second coat film of aluminum oxide formed on the first coat film. The thickness of the second coat film is at least 80 nm and at most 1000 nm. Here, the thickness of the first coat film is preferably at least 6 nm and at most 200 nm.

A nitride light-emitting element includes: a GaN substrate; an n-type semiconductor layer including an n-type nitride-based semiconductor, the n-type semiconductor layer being disposed on the GaN substrate; a p-type semiconductor layer including a p-type nitride-based semiconductor; an active layer including a nitride-based semiconductor containing Ga or In, the active layer being disposed between the n-type semiconductor layer and the p-type semiconductor layer; and a p-type electron barrier layer including Al, the p-type electron barrier layer being disposed between the active layer and the p-type semiconductor layer. The p-type electron barrier layer shows a composition distribution in which a position in a depth direction of the p-type electron barrier layer is taken as a horizontal axis, and a proportion of an Al element in a total amount of group III elements at each position is taken as a vertical axis. The composition distribution has maximum value A.sub.1. The maximum value A.sub.1 is 46 mol % or more. The composition distribution has a width La of a region including the maximum value A.sub.1 in which the proportion of the Al element is continuously 0.9 times or more maximum value A.sub.1. A ratio of the width La to a thickness Lm of the p-type electron barrier layer is 0.2 or less.

A semiconductor laser device includes an n-type clad layer, a first p-type clad layer and a ridge stripe. The device also includes an active layer interposed between the n-type clad layer and the first p-type clad layer, and a current-blocking layer formed on side surfaces of the ridge stripe. The ridge stripe of the device includes a second p-type clad layer formed into a ridge stripe shape on the opposite surface of the first p-type clad layer from the n-type clad layer. The ridge stripe is formed such that a first ridge width as the width of a surface of the second p-type clad layer exists on the same side as the first p-type clad layer and a second ridge width as the width of a surface of the second p-type clad layer exists on the opposite side from the first p-type clad layer.