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 vertical light source includes an upper mirror and a lower mirror. An active region is between the upper and lower mirror. The light source includes an inner mode confinement region and outer current blocking region. The outer current blocking region includes a common epitaxial layer that includes an epitaxially regrown interface which is between the active region and upper mirror, and a conducting channel including acceptors is in the inner mode confinement region. The current blocking region includes a first impurity doped region with donors between the epitaxially regrown interface and active region, and a second impurity doped region with acceptors is between the first doped region and lower mirror. The outer current blocking region provides a PNPN current blocking region that includes the upper mirror or a p-type layer, first doped region, second doped region, and lower mirror or an n-type layer.

A nitride semiconductor laser device of one embodiment of the present disclosure includes a single-crystal substrate, a base layer, a sheet-shaped structure, a light emitting layer, and a resonator mirror. The single-crystal substrate extends in one direction. The base layer is provided on the single-crystal substrate and includes a nitride semiconductor. The sheet-shaped structure is provided on the base layer to stand in a direction perpendicular to the base layer. The sheet-shaped structure has an area of a side surface that is greater than an area of an upper surface. The side surface extends in a longitudinal direction of the single-crystal substrate. The sheet-shaped structure includes a nitride semiconductor. The light emitting layer is provided at least on the side surface of the sheet-shaped structure. The light emitting layer includes a nitride semiconductor. The resonator mirror is provided by a pair of end surfaces of the sheet-shaped structure that oppose each other in the longitudinal direction.

A Schottky diode is monolithically integrated into the core of an infrared semiconductor laser (e.g., a quantum cascade laser) to create a heterodyned infrared transceiver. The internal mode field of the infrared semiconductor laser couples to an embedded Schottky diode and can mix the infrared fields to generate a response at the difference frequency.

A semiconductor optical device includes: a ridge stripe structure portion 20 in which a first compound semiconductor layer 31, an active layer 32, and a second compound semiconductor layer 32 are stacked and which has a first end surface 21 which emits light and a second end surface 22 opposite to the first end surface 21; and a current regulation region 41 provided to be adjacent to at least one of ridge stripe adjacent portions 40 positioned at both sides of the ridge stripe structure portion 20, at the second end surface side, and to be away from the ridge stripe structure portion 20. A bottom surface of the current regulation region 41 is under the active layer 33, and a top surface of the ridge stripe adjacent portion 40 excluding the current regulation region 41 is above the active layer 33.

A hybrid III-V on silicon laser device includes a layer structure, with a stack of III-V semiconductor gain materials, a silicon waveguide core and a cladding structure. The semiconductor gain materials stack is along a stacking direction, which is perpendicular to a main plane of the stack. The silicon waveguide core extends along a longitudinal direction, parallel to the main plane. The cladding structure extends between said waveguide core and the stack. The device further comprises an optical coupling structure formed in the layer structure. This coupling structure is designed: 1) to allow a hybrid-mode optical coupling of radiation between the stack of III-V semiconductor gain materials and the tapered waveguide core; and 2) to favor a coupling of a fundamental transverse optical mode of said radiation over a coupling of one or more higher-order transverse optical modes of said radiation from the stack into the waveguide core.

The present disclosure is generally directed to an EML with a filter layer disposed between an active region of the EML and a substrate of the EML to absorb a portion of unmodulated light energy, and preferably the unmodulated light energy caused by transverse electric (TE) substrate mode. The filter layer preferably comprises a material with an energy band gap (Eg) that is less than the energy band gap of the predetermined channel wavelength to absorb unmodulated laser light.

A semiconductor vertical light source includes an upper mirror and a lower mirror. An active region is between the upper and lower mirror. The light source includes an inner mode confinement region and outer current blocking region. The outer current blocking region includes a common epitaxial layer that includes an epitaxially regrown interface which is between the active region and upper mirror, and a conducting channel including acceptors is in the inner mode confinement region. The current blocking region includes a first impurity doped region with donors between the epitaxially regrown interface and active region, and a second impurity doped region with acceptors is between the first doped region and lower mirror. The outer current blocking region provides a PNPN current blocking region that includes the upper mirror or a p-type layer, first doped region, second doped region, and lower mirror or an n-type 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 optical element includes a first indirect bandgap semiconductor part that includes a first-conductivity-type impurity; a second indirect bandgap semiconductor part that includes a first-conductivity-type impurity; a third indirect bandgap semiconductor part that includes a second-conductivity-type impurity; a fourth indirect bandgap semiconductor part that includes a second-conductivity-type impurity; and a fifth indirect bandgap semiconductor part that includes a second-conductivity-type impurity. The first indirect bandgap semiconductor part has one or more first recesses. The one or more first recesses contain a medium having a refractive index lower than a refractive index of the second indirect bandgap semiconductor part. The fifth indirect bandgap semiconductor part has one or more second recesses. The one or more second recesses contain a medium having a refractive index lower than a refractive index of the fourth indirect bandgap semiconductor part.