A distributed feedback (DFB) laser outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The DFB laser includes a separate confinement heterostructure layer positioned between the quantum well active layer and then-type cladding layer. The DFB laser includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and then-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The DFB laser has a function to select a specific wavelength by returning a specific wavelength in the wavelength-variable laser.

A planar waveguide laser crystal assembly includes an optical bench and a laser crystal mount mounted on the optical bench. The laser crystal mount includes an upper housing having an interior horizontal surface and an exterior horizontal, a lower housing coupled to the upper housing and having an interior horizontal surface and an exterior horizontal surface, and a cavity defined between the interior horizontal surfaces of the upper and lower housings. A laser crystal is mounted in the cavity of the laser crystal mount. Each of the exterior horizontal surfaces of the upper and lower housings is oriented parallel to a length of the laser crystal. The laser crystal assembly further includes a heat dissipating structure thermally coupled to at least one of the exterior horizontal surfaces of the upper and lower housings to dissipate heat transferred from the laser crystal mount.

A semiconductor optical device is provided with a semiconductor substrate that has a length and width, a laser section that is provided on the semiconductor substrate and includes an active layer and an optical waveguide section that is provided adjacent to the laser section on the semiconductor substrate and is joined to the laser section. The optical waveguide section includes a core layer that is connected to an end portion of the active layer, and a pair of cladding layers between which the core layer is sandwiched and emits, from an emission end surface, light incident from the joining interface between the optical waveguide section and the laser section. The semiconductor optical device may be also provided with a reflection suppression layer that is provided on the upper surface of the optical waveguide section.

A semiconductor vertical light source includes upper and lower mirrors with an active region in between, an inner mode confinement region, and an outer current blocking region that includes a common epitaxial layer including an epitaxially regrown interface between the active region and upper mirror. A conducting channel including acceptors is in the inner mode confinement region. The current blocking region includes a first impurity doped region with donors between the epitaxially regrown interface and active region, and a second impurity doped region with acceptors between the first doped region and lower mirror. The outer current blocking region provides a PNPN current blocking region that includes the upper mirror or a p-type layer, first doped region, second doped region, and lower mirror or an n-type layer. The first and second impurity doped region force current flow into the conducting channel during normal operation of the light source.

Disclosed are embodiments of bidirectionally emitting semiconductor (BEST) laser architectures including higher order mode suppression structures. The higher order mode suppression structures are centrally located and extend from an inner transition boundary, which may be established by confronting high reflector (HR) facets in some embodiments or a central plane defining two sides of a unitary, bidirectional optical cavity in other embodiments. Examples of the higher order mode suppression structures include narrow regions of bidirectional flared laser oscillator waveguide (FLOW) devices, which are also referred to as reduced mode diode (REM) devices; high-index regions of bidirectional higher-order mode suppressed laser (HOMSL) devices; and non- or less-etched gain-guided lateral waveguides of bidirectional low divergence semiconductor laser (LODSL) devices. The aforementioned devices may also include scattering features, distributed feedback (DFB) gratings, distributed Bragg reflection (DBR) gratings, and combination thereof that also act as supplemental higher order mode suppression structures.

An optical semiconductor device outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The optical semiconductor device includes a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer. The optical semiconductor device further includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The optical semiconductor device is applied to a ridge-stripe type laser.

A semiconductor vertical light source includes upper and lower mirrors with an active region in between, an inner mode confinement region, and an outer current blocking region that includes a common epitaxial layer including an epitaxially regrown interface between the active region and upper mirror. A conducting channel including acceptors is in the inner mode confinement region. The current blocking region includes a first impurity doped region with donors between the epitaxially regrown interface and active region, and a second impurity doped region with acceptors between the first doped region and lower mirror. The outer current blocking region provides a PNPN current blocking region that includes the upper mirror or a p-type layer, first doped region, second doped region, and lower mirror or an n-type layer. The first and second impurity doped region force current flow into the conducting channel during normal operation of the light source.

A semiconductor vertical resonant cavity light source includes an upper and lower mirror that define a vertical resonant cavity. An active region is within the cavity for light generation between the upper and lower mirror. At least one cavity spacer region is between the active region and the upper mirror or lower mirror. The cavity includes an inner mode confinement region and an outer current blocking region. An index guide in the inner mode confinement region is between the cavity spacer region and the upper or lower mirror. The index guide and outer current blocking region each include a lower and upper epitaxial material layer thereon with an epitaxial interface region in between. At least a top surface of the lower material layer includes aluminum in the interface region throughout a full area of an active part of the vertical light source.

The present invention keeps a residual stress small which may occur in a metal shaped object (MO) while keeping a time short which is to be taken for carrying out main heating and preheating. An irradiation device (13) carries out a first heating step of heating a powder bed (PB) with laser light (LL) so that a temperature (T) of the powder bed (PB) is higher than 0.8 times as high as a melting point (Tm) of the metal powder and a second heating step of heating the powder bed (PB) with cladding light (CL) before or after the first heating step so that a temperature (T) of the powder bed (PB) is 0.5 times to 0.8 times as high as the melting point (Tm) of the metal powder.

A laser diode, comprising a transverse waveguide that is orthogonal to the lateral waveguide comprising an active layer between an n-type waveguide layer and a p-type waveguide layer, wherein the transverse waveguide is bounded by an n-type cladding layer on an n-side and p-type cladding layer on a p-side and a lateral waveguide bounded in a longitudinal direction at a first end by a high reflector (HR) coated facet and at a second end by a partial reflector (PR) coated facet, the lateral waveguide further comprising a buried higher order mode suppression layer (HOMSL) disposed beneath the p-cladding within the lateral waveguide or on one or both sides of the lateral waveguide or a combination thereof, wherein the HOMSL extends in a longitudinal direction from the HR facet a length less than the distance between the HR facet and the PR facet.