A broad area semiconductor laser device includes a waveguide region and a filter region. The waveguide region includes an active region into which current is injected, and a cladding region that sandwiches the active region. The active region either protrudes or is recessed with respect to the filter region, so as to promote the divergence of higher order modes in the filter region.

A broad area semiconductor laser device includes a waveguide region and a filter region. The waveguide region includes an active region into which current is injected, and a cladding region that sandwiches the active region. The active region either protrudes or is recessed with respect to the filter region, so as to promote the divergence of higher order modes in the filter region.

A quantum cascade laser and its method of fabrication are provided. The quantum cascade laser comprises one or more p-type electrical isolation regions and a plurality of electrically isolated laser sections extending along a waveguide axis of the laser. An active waveguide core is sandwiched between upper and lower n-type cladding layers and the active core and the upper and lower n-type cladding layers extend through the electrically isolated laser sections of the quantum cascade laser. A portion of the upper n-type cladding layer comprises sufficient p-type dopant to have become p-type and to have become an electrical isolation region, which extends across at least a part of the thickness upper n-type cladding layer along a projection separating the sections of the quantum cascade laser. Laser structures are also contemplated where isolation regions are solely provided at the window facet sections of the laser to provide vertical isolation in the facet sections, to reduce the current into the facet regions of the laser, and help minimize potentially harmful facet heating.

A semiconductor laser includes a main body, a strip having a narrower width provided on the main body, and an active zone that generates light radiation, wherein surfaces of the main body laterally with respect to the strip and side surfaces of the strip are covered with an electrically insulating protective layer, an electrically conductive layer as a contact is provided on a top side of the strip, a cavity is provided between a side surface of the strip and the protective layer at least in a delimited section.

An optical semiconductor device includes: an n-type semiconductor substrate; an n-type cladding layer provided on the n-type semiconductor substrate; an active layer of a semiconductor laser provided on the n-type cladding layer; a waveguide layer of a waveguide provided on the n-type cladding layer and having a side facing a side of the active layer; a p-type cladding layer provided on the active layer and the waveguide layer; and a middle layer provided between the side of the active layer and the side of the waveguide layer, provided between the n-type cladding layer and the waveguide layer, not provided on the active layer, and having a band gap greater than a band gap of the waveguide layer.

The invention relates to a surface-emitting photonic crystal laser (1). The laser has an active layer for generating electromagnetic radiation by combining charge carriers, wherein the active layer has a first main surface and a second main surface lying opposite the first main surface. The first main surface is equipped with a first waveguide layer, and the second main surface is equipped with a second waveguide layer, said waveguide layers having regions which are arranged periodically relative to one another and additional regions which have different refractive indices and which form a photonic crystal. The first waveguide layer is equipped with a first casing layer which has at least one p-connection region for injecting electrically positive charge carriers into the active layer and at least one n-connection region for injecting electrically negative charge carriers into the active layer. The invention additionally relates to a method for producing a surface-emitting photonic crystal laser and to an optoelectronic system.

With a method for manufacturing a semiconductor device, a semiconductor layer having a protrusion on a main face is formed. The protrusion includes an upper face and side faces. A conductive layer on a region that includes at least the upper face and the side faces of the protrusion is formed. A first mask that partially covers a surface of the conductive layer is formed. A part of the conductive layer is etched by using the first mask in a first etching process. A second mask that at least partially covers the surface of the conductive layer that has undergone the first etching process is formed. A part of the conductive layer is etched by using the second mask to expose a part of the semiconductor layer and to form the conductive layer into an electrode in a second etching process.

Methods, systems, and apparatus, including a laser including a layer having first and second regions, the first region including a void; a mirror section provided on the layer, the mirror section including a waveguide core, at least part of the waveguide core is provided over at least a portion of the void; a first grating provided on the waveguide core; a first cladding layer provided between the layer and the waveguide core and supported by the second region of the layer; a second cladding layer provided on the waveguide core; and a heat source configured to change a temperature of at least one of the waveguide core and the grating, where an optical mode propagating in the waveguide core of the mirror section does not incur substantial loss due to interaction with portions of the mirror section above and below the waveguide core.

Methods, systems, and apparatus, including an optical receiver including an optical source, including a substrate; a laser provided on the substrate, the laser having first and second sides and outputting first light from the first side and second light from the second side, the first light output from the first side of the laser has a first power and the second light output from the second side has a second power; and a first modulator that receives the first light and a second modulator that receives the second light, such that the power of the first light at an input of the first modulator is substantially equal to the power of the second light at an input of the second modulator.

Methods, systems, and apparatus, including an optical receiver including a laser including a gain section; and a first tunable reflector configured to output a reference signal; a first coupler formed over the substrate; a shutter variable optical attenuator formed over the substrate, the shutter variable optical attenuator including an input port configured to receive the first portion of the reference signal from the laser; and an output port configured to provide or to block, based on a control signal, the first portion of the reference signal from the laser; and a second coupler including a first port configured to receive the first portion of the reference signal from the shutter variable optical attenuator; and a second port configured to (i) provide the first portion of the reference signal from the shutter variable optical attenuator to an optical analyzer or (ii) receive a data signal from a transmitter.