A semiconductor layer structure may include a substrate, a buffer layer formed on the substrate, and a set of epitaxial layers formed on the buffer layer. The buffer layer may have a thickness that is greater than 2 micrometers (m). The set of epitaxial layers may include a quantum well layer. A quantum well intermixing region may be formed in association with the quantum well layer and a material diffused from a region of a surface of the semiconductor layer structure.

A laser diode includes a semiconductor structure of a lower Bragg reflector layer, an active region, and an upper Bragg reflector layer. The upper Bragg reflector layer includes a lasing aperture having an optical axis oriented perpendicular to a surface of the active region. The active region includes a first material, and the lower Bragg reflector layer includes a second material, where respective lattice structures of the first and second materials are independent of one another. Related laser arrays and methods of fabrication are also discussed.

A laser array includes a plurality of laser diodes arranged and electrically connected to one another on a surface of a non-native substrate. Respective laser diodes of the plurality of laser diodes have different orientations relative to one another on the surface of the non-native substrate. The respective laser diodes are configured to provide coherent light emission in different directions, and the laser array is configured to emit an incoherent output beam comprising the coherent light emission from the respective laser diodes. The output beam may include incoherent light having a non-uniform intensity distribution over a field of view of the laser array. Related devices and fabrication methods are also discussed.

An edge-emitting laser having a small vertical emitting angle includes an upper cladding layer, a lower cladding layer and an active region layer sandwiched between the upper and lower cladding layers. By embedding a passive waveguide layer within the lower cladding to layer, an extended lower cladding layer is formed between the passive waveguide layer and the active region layer. In addition, the refractive index (referred as n-value) of the passive waveguide layer is larger than the n-value of the extended lower cladding layer. The passive waveguide layer with a larger n-value would guide the light field to extend downward. The extended lower cladding layer can separate the passive waveguide layer and the active region layer and thus expand the near-field distribution of laser light field in the resonant cavity, so as to obtain a smaller vertical emitting angle in the far-field laser light field.

A semiconductor laser includes a first optical waveguide including a first reflection unit and a second reflection unit, and a confinement portion. The first reflection unit and the second reflection unit are waveguide type reflection units each having a structure in which the refractive index is periodically modulated. The first reflection unit, the confinement portion, and the second reflection unit constitute a Fabry-Perot type optical resonator. The semiconductor laser also includes a second optical waveguide disposed along a first optical waveguide to extend from the confinement portion to the second reflection unit side. The second optical waveguide serves as an extraction optical waveguide. Further, a third reflection unit formed continuously with the second optical waveguide is provided at a location corresponding to the first reflection unit.

A laser array includes a plurality of laser emitters arranged in a plurality of rows and a plurality of columns on a substrate that is non-native to the plurality of laser emitters, and a plurality of driver transistors on the substrate adjacent one or more of the laser diodes. A subset of the plurality of laser emitters includes a string of laser emitters that are connected such that an anode of at least one laser emitter of the subset is connected to a cathode of an adjacent laser emitter of the subset. A driver transistor of the plurality of driver transistors is configured to control a current flowing through the string.

A tunable laser that includes an array of parallel optical amplifiers is described. The laser may also include an intracavity NM coupler that couples power between a cavity mirror and the array of parallel optical amplifiers. Phase adjusters in optical paths between the NM coupler and the optical amplifiers can be used to adjust an amount of power output from M1 ports of the NM coupler. A tunable wavelength filter is incorporated in the laser cavity to select a lasing wavelength.

According to a first aspect, the present disclosure relates to a semiconductor sub-assembly comprising a semiconductor device comprising: a semi-insulating substrate (201); a first section (210) configured to emit light; at least a second section (220) configured to modulate light emitted by said first section (210); wherein said first section (210) and said at least second section (220) are monolithically integrated on said semi-insulating substrate (201) and have a common optical waveguide (205); said first section (210) forms a first vertical PIN junction with a first electrode (212) and a second electrode (214) on said semi-insulating substrate (201); said second section (220) forms a second vertical PIN junction with a first electrode (222) and a second electrode (224) on said semi-insulating substrate (201); an electric resistance between said first electrode (212) of said first section (210) and said first electrode (222) of said second section (220) is superior to about 50 ohms; and an electric resistance between said second electrode (214) of said first section (210) and said second electrode (224) of said second section (220) is superior to about 50 ohms.

A photonic crystal surface-emitting laser includes a light emitting region from which light is emitted in a direction crossing an in-plane direction, and a current blocking region that is adjacent to the light emitting region in the in-plane direction and in which current is less likely to flow than in the light emitting region. The light emitting region and the current blocking region each include a photonic crystal layer. The photonic crystal layer has a first region and second regions periodically arranged in the first region. A refractive index of each of the second regions is different from that of the first region. The light emitting region includes a first semiconductor layer, an active layer, and a second semiconductor layer. The first semiconductor layer, the active layer, and the second semiconductor layer are sequentially stacked on top of one another in an emission direction of the light.

A method and device for emitting electromagnetic radiation at high power using nonpolar or semipolar gallium containing substrates such as GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, is provided. In various embodiments, the laser device includes plural laser emitters emitting green or blue laser light, integrated a substrate.