Disclosed in the present invention are a laser chip and a preparation method therefor. Said method comprises: providing a laser epitaxial structure, the laser epitaxial structure comprising an active layer, and a cladding layer and a contact layer which are sequentially stacked on the active layer; covering a first mask layer on the contact layer, and a photolithograph step is performed on the first mask layer to form a first window region; performing primary etching on the contact layer by means of the first window region, so as to form a second window region corresponding to the first window region and exposing the cladding layer; performing zinc diffusion on the cladding layer and the active layer by means of the first window region and the second window region; removing the first mask layer; covering a second mask layer on the contact layer, and a photolithograph step is performed on the second mask layer to form a third window region, the projection of the third window region on the contact layer being located at the periphery of the second window region; and performing secondary etching on the contact layer by means of the third window region, so as to enlarge the second window region to correspond to the third window region. The described method can effectively increase a catastrophic optical mirror damage threshold.

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 device includes an N-type cladding layer, an active layer, and a P-type cladding layer. The active layer includes a well layer, a P-side first barrier layer above the well layer, and a P-side second barrier layer above the P-side first barrier layer. The P-side second barrier layer has an AI composition ratio higher than an AI composition ratio of the P-side first barrier layer. The P-side second barrier layer has band gap energy greater than band gap energy of the P-side first barrier layer. The semiconductor laser device has an end face window structure in which band gap energy of a portion of the well layer in a vicinity of an end face that emits the laser light is greater than band gap energy of a central portion of the well layer in a resonator length direction.

Provided are an epitaxial structure and a semiconductor chip applying same. The epitaxial structure comprises a quantum well structure, a P-type contact layer, and an electrode layer, which are stacked in sequence; the P-type contact layer comprises a first step part and a second step part that are disposed in a step shape, the second step part being closer to the quantum well structure relative to the first step part; the first step part and the second step part are filled with a first insulation part. By means of the described method, the anti-catastrophic optical mirror damage value of a semiconductor chip can be effectively improved.

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.

A semiconductor laser device includes a laser resonator including a layered structure in which a lower cladding layer, an active layer, and an upper cladding layer are formed over a semiconductor substrate, and a ridge that is formed on the upper cladding layer. The laser resonator emits laser light having a beam profile. When viewed in plan from a direction orthogonal to the semiconductor substrate, the laser resonator has an emission area on its emission end face. When the emission end face of the laser resonator is viewed in front, a virtual line defined by the intensity being 1/e.sub.2 of the peak intensity of the beam profile of the laser light fits inside the upper cladding layer in the emission area.

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 laser element includes: a first conductivity-type cladding layer; a first guide layer disposed above the first conductivity-type cladding layer; an active layer disposed above the first guide layer; and a second conductivity-type cladding layer disposed above the active layer. A window region is formed in a region of the active layer including part of at least one of the front-side end face or the rear-side end face, the first conductivity-type cladding layer consists of (Al.sub.xGa.sub.1-x).sub.0.5In.sub.0.5P, the first guide layer consists of (Al.sub.yGa.sub.1-y).sub.0.5In.sub.0.5P, and the second conductivity-type cladding layer consists of (Al.sub.zGa.sub.1-z).sub.0.5In.sub.0.5P, where x, y, and z each denote an Al composition ratio, 0<x−y<z−y is satisfied, and D/L>0.03 is satisfied, where L denotes a length of the resonator and D denotes a length of the window region in the first direction.

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 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.