In a method for manufacturing a light-emitting element, a second irradiation process includes forming a first modified region at a first distance from a second surface in a thickness direction of a sapphire substrate, forming a second modified region at a second distance from the second surface in the thickness direction, the second distance being less than the first distance, the second modified region being shifted in a first direction from the first modified region, and forming a third modified region at a third distance from the second surface in the thickness direction, the third distance being less than the second distance, the third modified region overlapping the first modified region in a top-view. In the thickness direction of the sapphire substrate, a greater number of modified regions that include second modified portions are formed than modified regions that include first modified portions.

A laser element includes a transparent substrate, a conductive layer on the transparent substrate, an adhesive layer, attached to the transparent substrate and having a first side surface, a laser unit, wherein the laser unit comprises a front conductive structure, attached to the adhesive layer and having a second side surface, a back conductive structure, which comprises a first detecting electrode and a second detecting electrode separated from the first detecting electrode, a passivation layer covering one of the first side surface and the second side surface, and first via holes extending from the back conductive structure to the conductive layer, wherein the first detecting electrode and the second detecting electrode are electrically connected to the conductive layer through the first via holes.

A semiconductor device includes: a substrate, including an upper surface and a first to a fourth side surfaces; wherein the upper surface includes a first edge connecting the first side surface and a second edge opposite to the first edge and connecting the second side surface; a first modified trace formed on the first side surface; and a semiconductor stack formed on the upper surface, including a lower surface connecting the upper surface of the substrate, and the lower surface comprises a fifth edge adjacent to the first edge and a sixth edge opposite to the fifth edge and adjacent to the second edge; wherein a shortest distance between the first edge and the fifth edge is S1 μm, and a shortest distance between the second edge and the sixth edge is S2 μm; wherein in a lateral view viewing from the third side surface, the first side surface forms a first acute angle with a degree of θ1 with the vertical direction, the second side surface forms a second acute angle with a degree of θ2 with the vertical direction, and a distance between the first modified trace and the upper surface in the vertical direction is D1 μm; and wherein S1, S2, θ1, θ2 and D1 satisfy the equation: D1≤0.2×(S1+S2)/tan θa, wherein θa=(θ1+θ2)/2.

A semiconductor optical device that achieves both of heat dissipation and light confinement and permits efficient current injection or application of an electric field is implemented. The semiconductor optical device includes: a core layer including an active region (1) made of a compound semiconductor; two cladding layers (5, 6) injecting current into the core layer; and a third cladding layer (4) made of a material having a larger thermal conductivity, a smaller refractive index, and a larger band gap than a material for any of the core layer and the two cladding layers.

In order to provide a QCL element operating in the near-infrared wavelength range, the present disclosure provides a quantum cascade laser element 1000 having a semiconductor superlattice structure (QCL structure 100) sandwiched between a pair of conductive sections 20 and 30. The semiconductor superlattice structure serves as an active region that emits electromagnetic waves. The active region has a plurality of unit structures 10U that are stacked on top of each other. Each unit structure includes four well layers 10W1-10W4 of a composition of Al.sub.xGa.sub.1-xN, separated from each other by barrier layers 10B1-10B5 of a composition of Al.sub.yGa.sub.1-yN with 0≤x<y≤1. Both of the conductive sections in the pair of conductive sections have a refractive index lower than that of the active region in which doped TCO inserted as a key role.

To provide a Fabry-Perot semiconductor laser diode obtained through a step of forming a mirror facet using an etching technology, in which the threshold current density for laser oscillation is reduced.

A method for manufacturing a semiconductor laser diode includes a step of forming a plurality of semiconductor laser diodes on a substrate, and then dividing the substrate into each semiconductor laser diode. The method includes a step of forming a laminate containing a first semiconductor layer 21, a waveguide layer (first guide layer 22, light emitting layer 23, second guide layer 24), and a second semiconductor layer 25 in this order on a substrate 1, a step of etching the laminate to separate the laminate into a portion serving as a resonance region and the other portion, an electrode layer forming step of forming a layer 51 serving as a second electrode on the second semiconductor layer 25 of the laminate to between the mirror facet 200 of the resonance region and a position where the substrate 1 is divided in the dividing step, and, after the electrode layer forming step, an etching step of simultaneously or sequentially performing the removal of a portion 51a formed at a position on the outer side relative to the mirror facet 200 of the layer serving as the second electrode and the formation the mirror facet 200.

A patterned epitaxial structure laser lift-off device, including a substrate, reshaping structures, a transmittance adjustment structure, a patterned epitaxial structure, gas transmission systems, an ultraviolet source, a lift-off chamber and a light entry window. The gas transmission systems are at two sides of the lift-off chamber; the light entry window is on the lift-off chamber; the ultraviolet source is above the outside of the light entry window; the patterned epitaxial structure is inside the lift-off chamber; the substrate is on the patterned epitaxial structure. The patterned epitaxial structure includes an epitaxial structure, a sapphire substrate, patterned structures, oblique interfaces and planar interfaces, several patterned structures being uniformly designed on the epitaxial structure, each of the patterned structures being a V-shaped groove structure formed by two oblique interfaces, two adjacent patterned structures being connected by means of a planar interface.

Methods for fabricating ultraviolet laser diode devices include providing substrate members comprising gallium and nitrogen or aluminum and nitrogen, forming an epitaxial material overlying a surface region of the substrate members, patterning the epitaxial material to form epitaxial mesa regions, depositing a bond media on at least one of the epitaxial mesa regions, bonding the bond media on at least one of the epitaxial mesa regions to a handle substrate, subjecting the sacrificial layer to an energy source to initiate release of the substrate member and transfer the at least one of the epitaxial mesa regions to the handle substrate, and processing the at least one of the epitaxial mesa regions to form the ultraviolet laser diode device.

There is provided a gallium nitride laminated substrate including: an n-type gallium nitride layer containing an n-type impurity; a p-type gallium nitride layer provided on the n-type gallium nitride layer, containing a p-type impurity, forming a pn-junction at an interface with the n-type gallium nitride layer, and having a p-type impurity concentration and a thickness such that, when a reverse bias voltage is applied to the pn-junction, a breakdown occurs due to a punchthrough phenomenon before occurrence of a breakdown due to an avalanche phenomenon; and an intermediate level layer provided on the p-type gallium nitride layer, containing a p-type gallium nitride which contains the p-type impurity at a higher concentration than the p-type gallium nitride layer, having at least one or more intermediate levels between a valence band and a conduction band, and configured to suppress an overcurrent resulting from a breakdown due to the punchthrough phenomenon in the p-type gallium nitride layer.

A device includes a first element having a passive waveguide structure supporting a first optical mode, a second element providing heat spreading functionality, a third element thermally coupled to the second element, having an active waveguide structure supporting a second optical mode, and a fourth element, at least partly butt-coupled to the third element, having an intermediate waveguide structure supporting intermediate optical modes. A tapered waveguide structure in either one of the first and fourth elements facilitates efficient adiabatic transformation between the first optical mode and one of the intermediate optical modes. No adiabatic transformation occurs between any of the intermediate optical modes and the second optical mode. Mutual alignments of the first, second, third and fourth elements are defined using lithographic alignment marks that facilitate precise alignment between layers formed during processing steps of fabricating the first, second, third and fourth elements.