Methods, devices, and systems for double-sided cooling of laser diodes are provided. In one aspect, a laser diode assembly includes a first heat sink, a plurality of submounts spaced apart from one another on the first heat sink, a plurality of laser diodes, and a second heat sink on top sides of the plurality of laser diodes. Each laser diode includes a corresponding active layer between a first-type doped semiconductor layer and a second-type doped semiconductor layer. A bottom side of each laser diode is positioned on a different corresponding submount of the plurality of submounts. The plurality of laser diode are electrically connected in series.

Provided is a semiconductor laser diode including multiple active layers and a grating layer. The semiconductor laser diode includes two (or more than two) active layers, a grating layer, and a tunnel junction. The grating layer and the tunnel junction are provided between the two active layers. The tunnel junction is electrically connected to the two active layers, and the two active layers share and are optically coupled to the grating layer, thereby improving the external quantum efficiency and slope efficiency of the semiconductor laser diode.

An on-chip integrated semiconductor laser structure and a method for preparing the same. The structure includes: an epitaxial structure including a first N contact layer, a first N confinement layer, a first active region, a first P confinement layer, a first P contact layer, an isolation layer, a second N contact layer, a second N confinement layer, a second active region, a second P confinement layer, and a second P contact layer sequentially deposited on a substrate; a first waveguide and a second waveguide; a first optical grating and a second optical grating; and current injection windows.

An optical semiconductor device includes an active layer having a plurality of quantum dot layers. The plurality of quantum dot layers includes at least one quantum dot player doped with a p-type impurity. Further, the plurality of quantum dot layers includes at least two quantum dot layers having different emission wavelengths and different p-type impurity concentrations.

The invention relates to a semiconductor laser comprising a semiconductor layer arrangement, having an active zone for radiation generation, as well as comprising a first resonator mirror, a second resonator mirror and a resonator arranged between the first and the second resonator mirror, which ends in a direction parallel to a main surface of the semiconductor layer arrangement. The semiconductor laser also comprises a first wavelength-selective absorption element which is arranged between the semiconductor layer arrangement and the first resonator mirror.

A semiconductor laser is formed to include a current blocking layer that is positioned below the active region of the device and used to minimize current spreading beyond the defined dimensions of an output beam's optical mode. When used in conjunction with other current-confining structures typically disposed above the active region (e.g., ridge waveguide, electrical isolation, oxide aperture), the inclusion of the lower current blocking layer improves the efficiency of the device. The current blocking layer may be used in edge-emitting devices or vertical cavity surface-emitting devices, and also functions to improve mode shaping and reduction of facet deterioration by directing current flow away from the facets.

The present disclosure relates to an optical amplifier configured for an image capturing device. The optical amplifier may include a substrate. The optical amplifier may also include an optical amplification region formed over the substrate. The optical amplification region may include a first optical amplification layer and a second optical amplification layer. The first optical amplification layer may be configured to amplify light at a first wavelength range, and the second optical amplification layer may be configured to amplify light at a second wavelength range. The optical amplifier may further include at least one electrode layer electrically contacting the optical amplification region.

According to embodiments, a semiconductor laser comprises a semiconductor layer stack, which comprises an active zone for generating radiation. The semiconductor laser also comprises a first resonator mirror, a second resonator mirror, and an optical resonator, which is arranged between the first and second resonator mirrors and extends in a direction parallel to a main surface of the semiconductor layer stack. A reflectance R1 of the first resonator mirror is wavelength-dependent, so that R1 or a product R of R1 and the reflectance R2 of the second resonator mirror in a wavelength range decreases from a target wavelength λ.sub.0 of the laser to λ.sub.0+Δλ from a value R0, wherein Δλ is selected as a function of a temperature-dependent shift in an emission wavelength.

A time-of-flight 3D imaging system includes a light source having a plurality of P-N junctions in electrical series, an imaging sensor, and a time measurement device configured to measure the elapsed time-of-flight between a pulse of output light being emitted from the plurality of P-N junctions in series and incoming light including the pulse of output light being detected at the imaging sensor.

A broad-spectrum laser for use in a MEMS laser scanning display device is provided. In one example, the broad-spectrum laser includes a laser diode emitter with plural quantum wells each having a different spectral peak. In another example, the broad-spectrum laser includes a laser diode emitter with a tunable absorber to achieve a broadened emissions spectrum. In another example, the broad-spectrum laser includes a laser diode emitter array having plural individual emitters with different spectral peaks.