In an embodiment, the gain-guided semiconductor laser includes a semiconductor layer sequence and electrical contact pads. The semiconductor layer sequence includes an active zone for radiation generation, a waveguide layer, and a cladding layer. The semiconductor layer sequence further includes a current diaphragm layer which is electrically conductive along a resonator axis (R) in a central region and electrically insulating in adjoining edge regions. Transverse to the resonator axis (R), the central region includes a width of at least 10 μm and the edge regions includes at least a minimum width. The minimum width is 3 μm or more. Seen in plan view, the semiconductor layer sequence as well as at least one of the contact pads on the semiconductor layer sequence are continuous components extending in the central region as well as on both sides at least up to the minimum width in the direction transverse to the resonator axis adjoining the central region and beyond the central region.

Systems and methods disclosed herein include an imaging system that may include a laser diode source; an objective lens positioned to direct a focus tracking beam from the light source onto a location in a sample container and to receive the focus tracking beam reflected from the sample; and an image sensor that may include a plurality of pixel locations to receive focus tracking beam that is reflected off of the location in the sample container, where the reflected focus tracking beam may create a spot on the image sensor. Some examples may further include a laser diode light source that may be operated at a power level that is above a power level for operation at an Amplified Spontaneous Emission (“ASE”) mode, but below a power level for single mode operation.

A single-mode micro-laser based on a single whispering gallery mode optical microcavity and a preparation method thereof described includes: preparing a desired single whispering gallery mode optical microcavity doped with rare earth ions or containing a gain material such as quantum dots, wherein an optical microcavity configuration include a micro-disk cavity, a ring-shaped microcavity, and a racetrack-shaped microcavity; a material type include lithium niobate, silicon dioxide, silicon nitride, etc.; preparing an optical fiber cone or an optical waveguide of a required size which can excite high-order modes of the optical microcavity, such as a ridge waveguide and a circular waveguides; and coupling, integrating, and packaging the optical fiber cone or the optical waveguide with the microcavity. A pump light is coupled to the optical fiber cone or the optical waveguide to excite a compound mode with a polygonal configuration.

A segmented VCSEL array having a plurality of individually addressable segments, each segment comprising one or more VCSELs. In some cases, at least two of the plurality of individually addressable segments may be driven in combination. The plurality of individually addressable segments, in some embodiments, may be centered around the same central point. An optical element may be used in conjunction with the segmented VCSEL array, and in some cases may be aligned to the central point. The optical element may be configured such that light passing therethrough may be directed according to which of the plurality of individually addressable segments is activated. In some embodiments, the optical element is a grating or diffractive optical element. The grating or diffractive optical element could be patterned with optical segments that each correspond to at least one the plurality of individually addressable segments.

Provided are a laser device and a method of transforming laser spectrum, which provide a laser frequency stabilization and significant narrowing a laser spectrum. A laser device includes at least one multiple longitudinal mode laser (L) for generating a laser light having a spectrum of multiple longitudinal modes; at least one high quality factor (high-Q) microresonator (M) optically feedback coupled to the at least one multiple longitudinal mode laser (L); and a tuner (TU) for tuning the spectrum of multiple longitudinal modes of the laser light. The laser device is configured to output an output laser light having an output spectrum with at least one dominant longitudinal laser mode each at a reduced linewidth of the dominant longitudinal laser mode. The laser device allows increasing an emission power of a narrow linewidth lasing without an additional amplification while keeping a compact size of a device with a limited number of optical elements.

An optical semiconductor device includes a semiconductor multilayer structure, an active region interposed between a first facet on a light emitting side and a second facet opposing to the first facet, and a first electrode layer provided on a top of the semiconductor multilayer structure and a second electrode layer provided on a bottom of the semiconductor multilayer structure; and an electrical connection region connected to at least one of the first electrode layer and the second electrode layer of the optical semiconductor device and used for injecting a current to the active region, and α>β and β>0 are satisfied where α is the contact area included in a half region on the first facet side in a top area of the optical semiconductor device and β is the contact area included in a half region on the second facet side.

A vertical cavity surface emitting laser (VCSEL) may include a top contact, wherein the top contact is associated with a particular shape, and wherein the particular shape is a toothed shape with a particular quantity of teeth. The VCSEL may include at least one implanted region. The VCSEL may include at least one top contact segment.

A VCSEL device having non-coaxial-with-one-another apertures and/or rotationally asymmetric apertures formed in layer(s) of the VCSEL structure to define more than one spatial mode in a light output in operation of the device. An array of such VCSEL devices configured to have different spatial modes at the output of different constituent VCSEL devices. Spatial asymmetry of structure of the constituent VCSEL devices and, therefore, arrays of VCSEL devices causes the overall light output to form an irregular grid of output spots of light. When the VCSEL array is equipped with an appropriate lens array, the spatial components of the light output of the VCSEL array are caused to overlap in the far at the imaging plane in a multiple spatial (and spectral) mode fashion, thereby reducing speckle in imaging applications.

A semiconductor laser is disclosed. Trim loss region is provided in inner ridge region of surface of transmission layer facing away from substrate, blind hole is provided in trim loss region, and distance from bottom surface of blind hole to surface of second cladding layer facing to substrate is smaller than evanescent wave length in transmission layer. Blind hole can affect optical field characteristics of light transmission in semiconductor laser by affecting evanescent wave. A method for fabricating a semiconductor laser is also provided.

A light-emission device includes: a first light emitting element chip; a second light emitting element chip having a light output higher than a light output of the first light emitting element chip, the second light emitting element chip being configured to be driven independently from the first light emitting element chip and arranged side by side with the first light emitting element chip; and a light diffusion member including a first region provided on an emission path of the first light emitting element chip and a second region provided on an emission path of the second light emitting element chip, and having a diffusion angle at the second region larger than a diffusion angle at the first region.