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.

A vertical cavity surface emitting laser (VCSEL) has first and second electrical contacts, and an optical resonator. The optical resonator has first and second distributed Bragg reflectors (DBRs), an active layer, a distributed heterojunction bipolar phototransistor (DHBP), and an optical guide. The DHBP has a collector layer, light sensitive layer; a base layer; and an emitter layer. There is an optical coupling between the active layer and the DHBP for providing an active carrier confinement by the DHBP. The optical guide guides an optical mode within the optical resonator during operation. The optical guide is outside a current flow which can be provided by the first and second electrical contacts during operation of the VCSEL. The optical guide is outside a layer sequence between the first and second electrical contacts in the vertical direction of the VCSEL. The optical guide has an oxide aperture arranged in the second DBR.

A laser source for use in a structured light projector includes a substrate, one or more first VCSELs on the substrate, and one or more second VCSELs on the substrate. The one or more first VCSELs each have a first aperture width and each separately extend above a surface of the substrate. The one or more second VCSELs each have a second aperture width different from the first aperture width, and each separately extend above a surface of the substrate. Using an array of VCSELs with different aperture widths provides emitted radiation having different wavelengths, thus providing different speckle patterns. When the different speckle patterns are averaged upon being received at the detector, speckle noise is reduced. The VCSEL can also include a plurality of subwavelength structures to steer the light output. Such subwavelength structures can also be used on the surface of other VCSELs, including standard VCSELs.

In a semiconductor laser according to an embodiment of the present disclosure, a ridge part has a structure in which a plurality of gain regions and a plurality of Q-switch regions are each disposed alternately with each of separation regions being interposed therebetween in an extending direction of the ridge part. The separation regions each have a separation groove that separates from each other, by a space, the gain region and the Q-switch region adjacent to each other. The separation groove has a bottom surface at a position, in a second semiconductor layer, higher than a part corresponding to a foot of each of both sides of the ridge part.

A light emitting device includes a substrate, a buffer layer, a first active layer, and a plurality of mesa regions. A portion of the first active layer includes a first electrical polarity. The plurality of mesa regions includes at least a portion of the first active layer, a light emitting region on the portion of the first active layer, and a second active layer on the light emitting region. A portion of the second active layer includes a second electrical polarity. The light emitting region is configured to emit light which has a target wavelength between 200 nm to 300 nm. A thickness of the light emitting region is a multiple of the target wavelength, and a dimension of the light emitting region parallel to the substrate is smaller than 10 times the target wavelength, such that the emitted light is confined to fewer than 10 transverse modes.

Disclosed is an electrically pumped vertical cavity laser structure operating in the mid-infrared region, which has demonstrated room-temperature continuous wave operation. This structure uses an interband cascade gain region, two distributed mirrors, and a low-loss refractive index waveguide. A preferred embodiment includes at least one wafer bonded GaAs-based mirror.

A semiconductor laser device with external resonator with stable longitudinal mode regardless of variation of drive current is disclosed. The device includes: a semiconductor light-emitting element having a pair of end faces with a light emitting section disposed therebetween, and an external resonator configured to oscillate light emitted from the semiconductor light-emitting element, the external resonator being formed by a resonator mirror disposed outside the semiconductor light-emitting element and one of the pair of end faces that is farther from the resonator mirror, wherein, as the semiconductor light-emitting element, a semiconductor light-emitting element having a structure which does not oscillate light emitted therefrom by itself is used. The device further includes a wavelength control element disposed in the optical path within the external resonator and configured to select a wavelength range of the light, and a driver circuit configured to perform fast modulation drive of the semiconductor light-emitting element.

A light emitting device includes a substrate, a buffer layer, a first active layer, and a plurality of mesa regions. A portion of the first active layer includes a first electrical polarity. The plurality of mesa regions includes at least a portion of the first active layer, a light emitting region on the portion of the first active layer, and a second active layer on the light emitting region. A portion of the second active layer includes a second electrical polarity. The light emitting region is configured to emit light which has a target wavelength between 200 nm to 300 nm. A thickness of the light emitting region is a multiple of the target wavelength, and a dimension of the light emitting region parallel to the substrate is smaller than 10 times the target wavelength, such that the emitted light is confined to fewer than 10 transverse modes.

A broad area quantum cascade laser subject to having high order transverse optical modes during operation includes a laser cavity at least partially enclosed by walls, and a perturbation in the laser cavity extending from one or more of the walls. The perturbation may have a shape and a size sufficient to suppress high order transverse optical modes during operation of the broad area quantum cascade laser, where a fundamental transverse optical mode is selected over the high order transverse optical modes. As a result, the fundamental transverse mode operation in broad-area quantum cascade lasers may be regained, when it could not otherwise be without such a perturbation.

The present disclosure relates to a ring-type laser system supporting circumferential radial emission. A cylindrical ring waveguide provides optical confinement in the radial and axial dimensions supporting a plurality of traveling wave modes with various degrees of confinement. The waveguide contains a gain media which is gain tailored to offset modal confinement factors of the modal constituency to favor radial emission. The selected modes radiate energy as they circulate the laser resonator with a 360 degree output coupler. The design is applicable toward both micro-resonators and resonators much larger than the optical wavelength, enabling high output powers and scalability. The circumferential radial laser emission can be concentrated by positioning the cylindrical ring laser inside a three-dimensional conical mirror thereby forming a laser ring of light propagating in the axial dimension away from the surface of the laser, which can be subsequently collimated for focused using conventional optics.