A semiconductor laser element includes: an n-type cladding layer disposed above an n-type semiconductor substrate (a chip-like substrate); an active layer disposed above the n-type cladding layer; and a p-type cladding layer disposed above the active layer, in which the active layer includes a well layer and a barrier layer, an energy band gap of the barrier layer is larger than an energy band gap of the n-type cladding layer, and a refractive index of the barrier layer is higher than a refractive index of the n-type cladding layer.

A semiconductor laser element that includes a semiconductor layer including a waveguide formed in an intra-layer direction of the semiconductor layer and a window region formed in a front-side end face of the waveguide, has a current-laser optical output characteristic in which, at an operating temperature of 25° C. ±3° C., a laser optical output has a maximum value at a first driving current value and the laser optical output is at most 20% of the maximum value at a second driving current value greater than the first driving current value, and is not damaged at the second driving current value.

A semiconductor laser device includes: a first conductivity side semiconductor layer, an active layer; and a second conductivity side semiconductor layer. The second conductivity side semiconductor layer includes a first semiconductor layer and a second semiconductor layer, the first semiconductor layer being closer to the active layer than the second semiconductor layer is. The second semiconductor layer defines a width of a current injection region for injecting current into an optical waveguide. The current injection region includes a width varying region in which a width varies. S1>S2, where S1 denotes a width of the width varying region on a front end face side, and S2 denotes a width of the width varying region on a rear end face side.

A semiconductor laser device includes an optical waveguide that extends toward a first end of the semiconductor laser device. The optical waveguide includes a first clad layer, an active layer, a second clad layer, and an electrode layer in this order. A reflecting surface, which has a dielectric film and a metal film in this order from the active layer, crosses the active layer at a second end of the optical waveguide.

A semiconductor laser includes a semiconductor layer including end faces and at least one of the end faces is configured as a light emission end face. The semiconductor layer includes a waveguide and a light window structure region. The waveguide has a first width and is extended between the end faces. The light window structure region includes an opening having a second width greater than the first width arranged along the waveguide and is formed continuously or intermittently from one to another of the end faces.

There are included: a substrate; a semiconductor laser part formed on the substrate by stacking a plurality of layers including an active layer; and an adjacent part formed on the substrate by stacking a plurality of layers including a core layer, and being an optical modulator or an optical waveguide in contact with the semiconductor laser part through butt joint joining thereto. In a semiconductor device including the semiconductor laser part and the adjacent part which are joined in a butt joint manner, at least a portion, of the semiconductor laser part, that is contact with the adjacent part is disordered.

The disclosure relates to a semiconductor laser includes a semiconductor layer sequence with an-n-type n-region, a p-type p-region and an active zone lying between the two for the purpose of generating laser radiation. A p-contact layer that is permeable to the laser radiation and consists of a transparent conductive oxide is located directly on the p-region for the purpose of current input. An electrically-conductive metallic p-contact structure is applied directly to the p-contact layer. The p-contact layer is one part of a cover layer, and therefore the laser radiation penetrates as intended into the p-contact layer during operation of the semiconductor laser. Two facets of the semiconductor layer sequence form resonator end surfaces for the laser radiation.

A laser chip including a plurality of stripes is disclosed, where a laser stripe can be grown with an initial optical gain profile, and its optical gain profile can be shifted by using an intermixing process. In this manner, multiple laser stripes can be formed on the same laser chip from the same epitaxial wafer, where at least one laser stripe can have an optical gain profile shifted relative to another laser stripe. For example, each laser stripe can have a shifted optical gain profile relative to its neighboring laser stripe, thereby each laser stripe can emit light with a different range of wavelengths. The laser chip can emit light across a wide range of wavelengths. Examples of the disclosure further includes different regions of a given laser stripe having different intermixing amounts.

A method of fabricating a semiconductor light-emitting device includes: (a) forming a semiconductor layer including a light-emitting layer on the first surface of a substrate; (b) forming a first trench and a second trench in the semiconductor layer, the first trench extending in a first direction that is parallel to a principal plane of the substrate, and the second trench being disposed inside and parallel to the first trench; (c) forming a third trench parallel to the first trench in the second surface of the substrate opposite to the first surface of the substrate; and (d) forming a semiconductor light-emitting device by dividing the substrate. In (d), an end of at least one divided side of the semiconductor light-emitting device is in the second trench. The first trench has a first width, and the second trench has a second width. The second width is less than the first width.

A grating coupled laser (GCL) includes an active section and a passive section. The passive section is butt coupled to the active section to form a butt joint with the active section. The active section includes an active waveguide. The passive section includes a passive waveguide, a transmit grating coupler, and a top cladding. The passive waveguide is optically coupled end to end with the active waveguide and includes a first portion and a second portion. The first portion of the passive waveguide is positioned between the second portion of the passive waveguide and the active waveguide. The transmit grating coupler is optically coupled to the passive waveguide and includes grating teeth that extend upward from the second portion of the passive waveguide. The top cladding is positioned directly above the first portion of the passive waveguide and is absent directly above at least some of the transmit grating coupler.