A distributed reflector (DR) laser may include a distributed feedback (DFB) region and a distributed Bragg reflector (DBR). The DFB region may have a length in a range from 30 micrometers (μm) to 100 μm and may include a DFB grating with a first kappa in a range from 100 cm.sup.−1 to 150 cm.sup.−1. The DBR region may be coupled end to end with the DFB region and may have a length in a range from 30-300 μm. The DBR region may include a DBR grating with a second kappa in a range from 150 cm.sup.−1 to 200 cm.sup.−1. The DR laser may additionally include a lasing mode and a p-p resonance frequency. The lasing mode may be at a long wavelength side of a peak of a DBR reflection profile of the DBR region. The p-p resonance frequency may be less than or equal to 70 GHz.

One aspect relates to a light-emitting element having a layer forming a resonance mode. The light-emitting element includes a structure body constituted by a substrate and a semiconductor laminate body including a first cladding layer, a second cladding layer, an active layer, and a resonance-mode forming layer including a basic layer and modified refractive index regions. A laser light output region and a metal electrode film are on opposing surfaces of the structure body. The metal electrode film includes a first layer forming ohmic contact with the structure body, a second layer reflecting light from the resonance-mode forming layer, a third layer, and a fourth layer for solder bonding. The third layer has a different composition from the second layer and the fourth layer, and has a lower diffusion degree than the second layer and the fourth layer to that of a solder material.

UV laser devices, systems, and methods are shown and/or described herein. Included are a method, device or system for VECSEL and MECSEL lasers including both barrier-pumped and in-well pumped lasers. Also disclosed is a method of manufacturing gain chips for use in the lasers, arrangements of lasers, and selection of proper non-linear crystal (NLC) for use in the device.

A laser is provided, including: a distributed Bragg mirror; a waveguide, the laser to emit light radiation along a longitudinal direction x, and the waveguide formed at least in part in a stack of layers made of III-V materials including at least one active region to emit the light radiation, the mirror including lateral corrugations distributed periodically along the direction x in a period Λ, the corrugations being carried by at least a lateral plane xz defined by the direction x and a first transverse direction z normal to the direction x, the corrugations having a dimension d along a second transverse direction y normal to the direction x; and a top electrode arranged on the waveguide along the direction z, the corrugations being partly located at lateral flanks of the top electrode, extending parallel to the plane xz, and extending only on the lateral flanks of the top electrode.

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.

A vertical-cavity surface-emitting laser (VCSEL) including a lower mirror, an upper mirror, an active layer interposed between the lower mirror and the upper mirror, an aperture forming layer interposed between the upper mirror and the active layer, and including an oxidation layer and a window layer surrounded by the oxidation layer, a ring-shaped trench passing through the upper mirror, the aperture forming layer, and the active layer to define an isolation region therein, and a plurality of oxidation holes disposed in the isolation region surrounded by the trench, and passing through the upper mirror and the aperture forming layer.

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 according to an embodiment of the present disclosure includes a semiconductor stack section. The semiconductor stack section includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, in which the second semiconductor layer is stacked on the first semiconductor layer and includes a ridge having a band shape, and an active layer. The semiconductor stack section further has an impurity region that is at least a portion of a region not facing the ridge and that is located at a position deeper than at least the active layer, in which the impurity region has an impurity concentration of the second conductivity type higher than an impurity concentration of the second conductivity type in a region, of the second semiconductor layer, facing the ridge.

A semiconductor optical amplifier includes: a substrate; a light source unit formed on the substrate; and an optical amplification part that amplifies light propagating in a predetermined direction from the light source unit and emits the amplified light in an emission direction intersecting with the substrate surface. The optical amplification part includes a conductive region extending in the predetermined direction along the substrate surface from the light source unit, and a nonconductive region formed around the conductive region. The conductive region includes a first region extending from the light source unit and having a predetermined width as seen from a direction perpendicular to the substrate surface, and a second region connected to the first region and having a width widened relative to the predetermined width of the first region, the second region being configured to expand the propagation light in a direction intersecting with the predetermined direction.

A portable lighting apparatus is provided with a gallium-and-nitrogen containing laser diode based white light source combined with an infrared illumination source which are driven by drivers disposed in a printed circuit board assembly enclosed in a compact housing and powered by a portable power supply therein. The portable lighting apparatus includes a first wavelength converter configured to output a white-color emission and an infrared emission. A beam shaper may be configured to direct the white-color emission and the infrared emission to a front aperture of a compact housing of the portable lighting apparatus. An optical transmitting unit is configured to project or transmit a directional light beam of the white light emission and/or the infrared emission for illuminating a target of interest, transmitting a pulsed sensing signal or modulated data signal generated by the drivers therein. In some configurations, detectors are included for depth sensing and visible/infrared light communications.