The surface emitting laser device according to the embodiment includes a substrate, a first metal layer disposed on the substrate, a second metal layer disposed on the first metal layer, and a third metal layer disposed between the first metal layer and the second metal layer.

The first to third metal layers may include different materials, and the second metal layer may include copper (Cu).

The third metal layer may prevent diffusion of copper from the second metal layer into the first metal layer.

A semiconductor light emitting device includes: a nitride semiconductor light emitting element including a nitride semiconductor substrate having a polar or semipolar surface and a nitride semiconductor multilayer film stacked on the polar or semipolar surface; and a mounting section to which the element is mounted. The nitride semiconductor multilayer film includes an electron block layer. The electron block layer has a smaller lattice constant than the nitride semiconductor substrate. The mounting section includes at least a first mounting section base. The first mounting section base is located close to the nitride semiconductor light emitting element. The first mounting section base has a lower thermal expansion coefficient than the nitride semiconductor multilayer film. The first mounting section base has a lower thermal conductivity than the nitride semiconductor multilayer film.

Provided here are: a mounting member having a front surface on which a diffusion bonding layer is formed; an optical semiconductor element provided with a light emitting part therein, and having a rear surface on which a diffusion bonding layer is formed; and an electrode layer formed from the diffusion bonding layer and the diffusion bonding layer by diffusion bonding therebetween; wherein, in the optical semiconductor element, the light emitting part is provided near a side of the optical semiconductor element so as to be displaced toward the mounting member. This configuration not only makes unnecessary the use of a solder, an Ag paste and the like to thereby prevent the light emitting part in the optical semiconductor element from being contaminated by the solder, but also allows the light emitting part to be closer to the mounting member-side to thereby achieve improvement in heat-dissipation capability.

An optical device according to the embodiment of the inventive concept includes a waveguide path including a light generation region, a wavelength variable region, and a light modulation region, a first light waveguide layer provided in the light generation region to generate light, a second light waveguide layer provided in the wavelength variable region and connected to the first light waveguide layer, a ring-shaped third light waveguide layer provided in the light modulation region and connected to the second light waveguide layer, and first and second light modulation electrodes spaced apart from each other with the light modulation region therebetween. Here, the first light modulation electrode, the third light waveguide layer, and the second light modulation electrode vertically overlap each other.

A surface light-emission type semiconductor light-emitting device includes a first semiconductor layer; a light-emitting layer provided on the first semiconductor layer; a second semiconductor layer provided on the light-emitting layer; an uneven structure provided on the second semiconductor layer, the uneven structure including a protrusion and a recess next to the protrusion; a first metal layer covering the uneven structure; and a second metal layer provided between the uneven structure and the first metal layer. The second metal layer is provided on one of a bottom surface of the recess, an upper surface of the protrusion, or a side surface of the protrusion. The second metal layer has a reflectance for light radiated from the light-emitting layer, which is less than a reflectance of the first metal layer for the light.

A method of forming a laser including device is provided that in one embodiment includes providing a laser chip including at least one ridge structure that provides an alignment features. The method further includes bonding a type IV photonics chip to the laser chip, wherein a vertical alignment feature from the type IV photonics chip is inserted in a recess relative to the at least one ridge structure that provides the alignment features of the laser structure.

According to various embodiments, there is provided a layer arrangement including a graphene layer; a gating electrode layer configured to provide a tuning voltage to the graphene layer; a laser layer configured to provide an electromagnetic wave; and a concentric-circular grating layer configured to couple the electromagnetic wave to the graphene layer.

A reproducible method for producing a resonant structure of a distributed-feedback semiconductor laser exhibiting a narrow waveguide of the order of some ten micrometers, the production of the diffraction grating being carried out subsequent to the step of producing the strip is provided. In a last step, a diffraction grating is engraved as a function of a desired precise wavelength.

A surface emitting quantum cascade laser includes an active layer, a first semiconductor layer, and first electrode. The active layer has a plurality of quantum well layers stacked therein. The active layer is capable of emitting laser light by inter-subband transition. The first semiconductor layer is provided on the active layer and having a first surface provided with a plurality of pits so as to constitute a two-dimensional lattice. The first electrode is provided on the first semiconductor layer and having a periodic opening. Each pit is asymmetric with respect to a line parallel to a side of the lattice. The laser light is emitted in a direction generally perpendicular to the active layer from a pit exposed to the opening.

A method is described for forming at least one metal contact on a surface of a semiconductor and a device with at least one metal contact. The method is used for forming at least one metal contact (60) on a surface (11) of a semiconductor (10) and has the steps of: applying a metal layer (20) of palladium onto the semiconductor surface (11), applying a mask (40, 50) onto the metal layer (20), and structuring the palladium of the metal layer (20) using the mask (40, 50), wherein lateral deposits (21) of the metal are formed on sidewalls of the mask by the structuring so that the mask is embedded between the deposits (21) and the structured metal layer (20′) after the structuring. Since the mask is conductive, it can remain embedded in the metal. The deposits and the mask form a part of the contact.