A semiconductor laser device includes: a support base having a plurality of mounting surfaces arranged in a first direction, wherein heights of the mounting surfaces from a reference plane that is parallel to the first direction decrease stepwise or gradually along the first direction; a first semiconductor laser element secured to a first mounting surface; a second semiconductor laser element secured to a second mounting surface; a first slow-axis collimator lens secured to the first mounting surface, the first slow-axis collimator lens being located at a position at which the first laser light is incident; a second slow-axis collimator lens directly or indirectly secured to the second mounting surface, the second slow-axis collimator lens being located at a position at which the second laser light is incident; and a first sealing cover that defines an inner space in which the first and second semiconductor laser elements are held.

A surface emission laser formed of a group III nitride semiconductor includes a first conductivity type first clad layer; a first conductivity type first guide layer on the first clad layer; a light-emitting layer on the first guide layer; a second guide layer on the light-emitting layer; and a second conductivity type second clad layer on the second guide layer. The first or second guide layer internally includes voids periodically arranged at square lattice positions with two axes perpendicular to one another as arrangement directions in a surface parallel to the guide layer. The voids have a polygonal prism structure or an oval columnar structure with a long axis and a short axis perpendicular to the long axis in the parallel surface, and the long axis is inclined with respect to one axis among the arrangement directions of the voids.

Provided is a semiconductor laser element including: a resonator structure; and a first reflection film and a second reflection film provided on a non-emission end surface of the resonator structure and an emission end surface of the resonator structure, respectively. Reflectance R of the second reflection film at a gain wavelength satisfies the following relational expression: R1≤R≤R(Oc)×C where R1 is reflectance of the second reflection film when the resonator structure performs laser oscillation with power 1.4 times a minimum value of threshold power which is minimum power for the resonator structure to perform the laser oscillation, R(Oc) is reflectance of the external resonance mirror, and C is a ratio of light, which is reflected by the external resonance mirror and is incident in the resonator structure, to light which is reflected by the external resonance mirror.

An irradiation unit is disclosed that includes a pump radiation source for emitting pump radiation in the form of a beam, a conversion element for at least partially converting the pump radiation into conversion radiation, and a support on which the conversion element is situated. The support accommodates a through-hole through which the beam including the pump radiation is incident on an incident surface of the conversion element, the though-hole being laterally delimited by an inner wall face of the support, at least one portion of the face tapering in the direction of the incident surface. During operation, the pump radiation conducted in the beam is at least intermittently at least in part, incident on the inner wall face of the support and is reflected thereby onto the incident surface.

A light source module that emits a combined laser beam, and includes: a plurality of semiconductor laser elements; and a control circuit that controls power of a laser beam emitted by each of the semiconductor laser elements. The semiconductor laser elements include: a first element group that emits a first laser beam; and a second element group that emits a second laser beam. The combined laser beam includes at least one of the first laser beam or the second laser beam. The control circuit maintains an average combined-beam wavelength that is an average wavelength of the combined laser beam constant for a change in power of the combined laser beam. When the power of the first laser beam and the power of the second laser beam are equal to each other, an average wavelength of the first laser beam is longer than an average wavelength of the second laser beam.

Porous III-nitrides having controlled/tuned optical, electrical, and thermal properties are described herein. Also disclosed are methods for preparing and using such porous III-nitrides.

An ultraviolet laser apparatus includes: a semiconductor laser that emits an excitation laser light; a fiber laser medium to which the excitation laser light enters from the semiconductor laser and that causes laser oscillation; and an external resonator that: converts a wavelength of a laser light oscillated in the fiber laser medium, and outputs an ultraviolet region continuous wave of at least 0.1W.

A method of removing a substrate from III-nitride based semiconductor layers with a cleaving technique. A growth restrict mask is formed on or above a substrate, and one or more III-nitride based semiconductor layers are grown on or above the substrate using the growth restrict mask. The III-nitride based semiconductor layers are bonded to a support substrate or film, and the III-nitride based semiconductor layers are removed from the substrate using a cleaving technique on a surface of the substrate. Stress may be applied to the III-nitride based semiconductor layers, due to differences in thermal expansion between the III-nitride substrate and the support substrate or film bonded to the III-nitride based semiconductor layers, before the III-nitride based semiconductor layers are removed from the substrate. Once removed, the substrate can be recycled, resulting in cost savings for device fabrication.

In a WBC system of the present disclosure, an LD bar array constituted by a plurality of LD bars is configured such that a main axis direction of an off-angle of at least one LD bar is reversed with respect to a main axis direction of an off-angle of the other LD bar. By doing so, even in the LD bar in which a wavelength distribution in a wafer exists, a difference between a designed lock wavelength and a gain peak wavelength can be kept within a range where an LD oscillation due to an external resonance is possible for all emitters in the LD bar, thereby an output in the WBC system can be maximized.

A radiation-emitting optoelectronic component may include a semiconductor chip or a semiconductor laser which, in operation of the component, emits a primary radiation in the UV region or in the blue region of the electromagnetic spectrum. The optoelectronic component may further include a conversion element comprising a first phosphor configured to convert the primary radiation at least partly to a first secondary radiation having a peak wavelength in the green region of the electromagnetic spectrum between 475 nm and 500 nm inclusive. The first phosphor may be or include BaSi.sub.4Al.sub.3N.sub.9, SrSiAl.sub.2O.sub.3N.sub.2, BaSi.sub.2N.sub.2O.sub.2, ALi.sub.3XO.sub.4, M*.sub.(1−x*−y*−z*) Z*.sub.z*[A*.sub.a*B*.sub.b*C*.sub.c*D*.sub.d*E*.sub.e*N.sub.4-n*O.sub.n*], and combinations thereof.