Embodiments of the invention describe apparatuses, optical systems, and methods related to utilizing optical cladding layers. According to one embodiment, a hybrid optical device includes a silicon semiconductor layer and a III-V semiconductor layer having an overlapping region, wherein a majority of a field of an optical mode in the overlapping region is to be contained in the III-V semiconductor layer. A cladding region between the silicon semiconductor layer and the III-V semiconductor layer has a spatial property to substantially confine the optical mode to the III-V semiconductor layer and enable heat dissipation through the silicon semiconductor layer.

A semiconductor laser element includes: an n-side semiconductor layer formed of a nitride semiconductor; an active layer disposed on or above the n-side semiconductor layer and formed of a nitride semiconductor; a p-side semiconductor layer disposed on the active layer, formed of a nitride semiconductor, and including: an undoped first part disposed in contact with an upper face of the active layer and comprising at least one semiconductor layer, an electron barrier layer disposed in contact with an upper face of the first part, containing a p-type impurity, and having a band gap energy that is larger than a band gap energy of the first part, and a second part disposed in contact with the upper face of the electron barrier layer and comprising at least one p-type semiconductor layer containing a p-type impurity; and a p-electrode disposed in contact with the upper face of the second part.

An edge-emitting semiconductor laser includes a semiconductor structure having a waveguide layer with an active layer, the waveguide layer extending in a longitudinal direction between first and second side facets of the semiconductor structure, the semiconductor structure has a tapering region adjacent to the first side facet, a thickness of the waveguide layer in the tapering region increases longitudinally, the waveguide layer is arranged between first and second cladding layers, a thickness of the second cladding layer in the tapering region of the semiconductor structure increases longitudinally, the tapering region includes first and second subregions, the first subregion is arranged closer to the first side facet than the second subregion, thickness of the waveguide layer increases longitudinally in the first subregion, thickness of the waveguide layer is constant in the longitudinal direction in the second subregion, and thickness of the second cladding layer increases longitudinally in the second subregion.

The present invention proposes an O-band silicon-based high-speed semiconductor laser diode for optical communication and its manufacturing method, by using different buffer layers to form the growth surface of InP material with low dislocation density; N—InAlGaAs is used instead of conventional N—InAlAs electron-blocking layer in the epi-structure to reduce the barrier for electrons to enter the quantum wells from N-type and lower the threshold; a superlattice structure quantum barrier is used instead of a single layer barrier structure to improve the transport of heavy holes in the quantum wells; and the material structure is adjusted to achieve a reliable O-band high direct modulation speed semiconductor laser diode for optical communication on silicon substrate.

A low voltage laser device having an active region configured for one or more selected wavelengths of light emissions.

An optical semiconductor integrated element comprises a laser section and a photodetector section which are arranged on the same semiconductor substrate, the laser section and the photodetector section each have a light confining layer which confines light, a cladding layer, and a contact layer formed of an InGaAs layer or an InGaAsP layer, the light confining layer of the laser section is an active layer, the contact layer of the photodetector section is a light absorption layer, each cladding layer is a ridge structure having a shape in which a width at a side of the light confining layer is narrower than a width at a side of the contact layer in a cross-section which is perpendicular to the optical axis, and on a side surface of the light confining layer, the cladding layer and the contact layer, a semiconductor embedded layer is not provided.

A gain medium for semiconductor optical amplifier in high-power operation includes a substrate with n-type doping; a lower clad layer formed overlying the substrate; a lower optical confinement stack overlying the lower clad layer; an active layer comprising a multi-quantum-well heterostructure with multiple well layers characterized by about 0.8% to 1.2% compressive strain respectively separated by multiple barrier layers characterized by about −0.1% to −0.5% tensile strain. The active layer overlays the lower optical confinement stack. The gain medium further includes an upper optical confinement stack overlying the active layer, the upper optical confinement stack being set thinner than the lower optical confinement stack; an upper clad layer overlying the upper optical confinement stack; and a p-type contact layer overlying the upper clad layer.

A manufacturing method of a nitride-based semiconductor light-emitting element includes: forming an n-type nitride-based semiconductor layer; forming, on the n-type nitride-based semiconductor layer, a light emission layer including a nitride-based semiconductor; forming, on the light emission layer in an atmosphere containing a hydrogen gas, a p-type nitride-based semiconductor layer while doping the p-type nitride-based semiconductor layer with a p-type dopant at a concentration of at least 2.0×10.sup.18 atom/cm.sup.3; and annealing the p-type nitride-based semiconductor layer at a temperature of at least 800 degrees Celsius in an atmosphere not containing hydrogen. In this manufacturing method, a hydrogen concentration of the p-type nitride-based semiconductor layer after the annealing is at most 5.0×10.sup.18 atom/cm.sup.3 and at most 5% of the concentration of the p-type dopant, and a hydrogen concentration of the light emission layer is at most 2.0×10.sup.17 atom/cm.sup.3.

The present disclosure provides fabrication of a laser diode with reliability at a high temperature of 80° C. or more in a high-power single mode by a process of thinly growing a second upper clad (P clad) layer at 1 μm or less in primary growth, appropriately controlling an upper portion Wt to 1.5 μm or more and a lower portion Wb to 4.0 μm or less of the wave guide, and then compensating for a second upper clad layer to 0.5 μm or more in regrowth, in order to compensate for disadvantages of a high-power and high-reliability laser diode device with a thick second upper clad layer (P clad). A second upper clad regrowth layer is applied to reduce internal resistance and voltage and reduce heat generated in the device to increase a Kink and a COD power, thereby improving the performance of a high-power and high-reliability laser diode.

An optical device has a gallium and nitrogen containing substrate including a surface region and a strain control region, the strain control region being configured to maintain a quantum well region within a predetermined strain state. The device also has a plurality of quantum well regions overlying the strain control region.