A high-reliability low-defect semiconductor light-emitting device and a method for manufacturing same. The high-reliability low-defect semiconductor light-emitting device includes: a semiconductor substrate layer; an active layer arranged on the semiconductor substrate layer; a doped semiconductor contact layer arranged on a side of the active layer away from the semiconductor substrate layer, where the doped semiconductor contact layer includes a first area and an edge area surrounding the first area; a protection layer arranged on a side of the edge area of the doped semiconductor contact layer away from the active layer; and a front electrode layer, arranged on a side of the first area away from the active layer, where an upper surface of the front electrode layer in the first area is lower than an upper surface of the protection layer. The semiconductor light-emitting device has both high reliability and reduced process control costs.

A semiconductor device includes a first pair of nitride semiconductor regions, and a current confinement region which includes a first portion, a second portion disposed on a side of the first portion, and a third portion disposed on another side of the first portion. A width of the second portion is larger than a width of the first portion, the width of the second portion is larger than a width between the first pair of nitride semiconductor regions, and both ends of the second portion are covered by the first pair of nitride semiconductor regions, respectively.

A semiconductor laser including current block layers disposed between a p-type clad layer and a p-type light guide layer and a current confinement region which is a region between the current block layers is configured as follows. A width of an opening portion of an insulating layer is made narrow above a wide portion of the current confinement region in which the wide portion, a tapered portion, a narrow portion, a tapered portion and the wide portion are disposed in this order between an incidence side (HR side) and an emission side (AR side), and both ends of the wide portion are covered by an insulating layer. According to such a configuration, it is possible to suppress generation of super luminescence in the wide portion, and it is thus possible to achieve improvement in beam quality and higher output of the beam.

A semiconductor laser is formed to include a current blocking layer that is positioned below the active region of the device and used to minimize current spreading beyond the defined dimensions of an output beam's optical mode. When used in conjunction with other current-confining structures typically disposed above the active region (e.g., ridge waveguide, electrical isolation, oxide aperture), the inclusion of the lower current blocking layer improves the efficiency of the device. The current blocking layer may be used in edge-emitting devices or vertical cavity surface-emitting devices, and also functions to improve mode shaping and reduction of facet deterioration by directing current flow away from the facets.

A broad area semiconductor laser device includes a waveguide region and a filter region. The waveguide region includes an active region into which current is injected, and a cladding region that sandwiches the active region. The active region either protrudes or is recessed with respect to the filter region, so as to promote the divergence of higher order modes in the filter region.

A broad area semiconductor laser device includes a waveguide region and a filter region. The waveguide region includes an active region into which current is injected, and a cladding region that sandwiches the active region. The active region either protrudes or is recessed with respect to the filter region, so as to promote the divergence of higher order modes in the filter region.

A quantum cascade laser and its method of fabrication are provided. The quantum cascade laser comprises one or more p-type electrical isolation regions and a plurality of electrically isolated laser sections extending along a waveguide axis of the laser. An active waveguide core is sandwiched between upper and lower n-type cladding layers and the active core and the upper and lower n-type cladding layers extend through the electrically isolated laser sections of the quantum cascade laser. A portion of the upper n-type cladding layer comprises sufficient p-type dopant to have become p-type and to have become an electrical isolation region, which extends across at least a part of the thickness upper n-type cladding layer along a projection separating the sections of the quantum cascade laser. Laser structures are also contemplated where isolation regions are solely provided at the window facet sections of the laser to provide vertical isolation in the facet sections, to reduce the current into the facet regions of the laser, and help minimize potentially harmful facet heating.

An edge-emitting semiconductor laser includes a semiconductor structure laterally bounded by first and second facets and having a central section and a first edge section, a layer sequence offset relative to the central section in the growth direction in the first edge section such that, in the first edge section, one of the cladding layers or one of the waveguide layers is arranged in the growth direction at a height of the active layer in the central section, the layer sequence includes an epitaxially grown additional layer arranged between the upper side and the lower cladding layer, the additional layer is not arranged between the upper side and the lower cladding layer in the central section, and the additional layer is electrically insulating or has doping with the opposite sign to the lower cladding layer.

A semiconductor laser is formed to include a current blocking layer that is positioned below the active region of the device and used to minimize current spreading beyond the defined dimensions of an output beam's optical mode. When used in conjunction with other current-confining structures typically disposed above the active region (e.g., ridge waveguide, electrical isolation, oxide aperture), the inclusion of the lower current blocking layer improves the efficiency of the device. The current blocking layer may be used in edge-emitting devices or vertical cavity surface-emitting devices, and also functions to improve mode shaping and reduction of facet deterioration by directing current flow away from the facets.

A semiconductor laser element includes a semiconductor stack with a ridge, a first electrode layer, a current injection prevention layer, and a second electrode layer. The semiconductor stack has an emission surface and a reflection surface. The first electrode layer extends in the lengthwise direction and disposed on the ridge in contact with the semiconductor stack. The current injection prevention layer partially covers the first electrode layer, and has one or more island portions. Each of the island portions is disposed in a center region of the ridge in plan view. The second electrode layer is disposed on the current injection prevention layer, and partially in contact with the first electrode layer.