Structured light projection system include narrow beam divergence semiconductor sources. The structured light projector system includes an array of narrow beam divergence semiconductor sources, and a projection lens operable to generate an image of the array of narrow beam divergence semiconductor source. Each narrow beam divergence semiconductor source can include an extended length mirror that helps suppress one or more longitudinal and/or transverse modes such that the beam divergence and/or the spectral width of emission is substantially reduced.

A semiconductor light-emitting device includes an active layer including quantum dots, a diffraction grating, a low-reflectance film disposed at a light-emitting end of the active layer, and a high-reflectance film disposed at another end of the active layer and having an optical reflectance higher than an optical reflectance of the low-reflectance film.

An optical device that includes: a base layer; a first region supported by the base layer, the first region including a first plurality of quantum-confined nanostructures and having a first density of quantum-confined nanostructures; a second region supported by the base layer, the first and second regions being non-overlapping regions, the second region having a second density of quantum-confined nanostructures lower than the first density; and an optical confinement structure supported by the base layer and configured to guide at least one transverse optical mode between a first end and a second end of the optical confinement structure. The first region substantially overlaps with the at least one transverse optical mode, and the first density varies across a cross-section of the optical device.

The inventive waveguide structure comprises a first waveguide region having a constant first width adapted to guide electromagnetic waves mode sustainably along its longitudinal axis; a second waveguide region adapted to guide electromagnetic waves mode sustainably along its longitudinal axis, wherein the longitudinal axis of the first waveguide region and the longitudinal axis of the second waveguide region form a common longitudinal axis of the waveguide structure, wherein a first end face of the first waveguide region and a first end face of the second waveguide region are aligned with each other, the width of the first end face of the second waveguide region corresponding to the first width, and the width of the second waveguide region along its longitudinal axis widens from the first end face to a second end face to a second width greater than the first width.

A semiconductor laser diode system may include a single longitudinal mode laser diode and a feedback system that monitors and controls the emission characteristics of the laser diode. The laser diode may include a gain medium and an optical feedback device. The feedback system may include a wavelength discriminator, an optical detector, a microprocessor, and a laser controller. Such a semiconductor laser diode system may be used to produce laser light having coherence length, wavelength precision, and wavelength stability that is equivalent to that of a gas laser. Accordingly, such a semiconductor laser diode system may be used in place of a traditional gas laser.

An on-chip laser includes a gain portion, a mirror in communication with the gain portion, a waveguide in communication with the gain portion, and a resonator optically coupled to the waveguide at an optical coupling. The resonator has a circular shape. The waveguide and the resonator are separate from the gain portion.

Vertical-cavity surface-emitting lasers (VCSELs) and methods for making such are provided. The VCSELs include stepped upper reflectors having respective differently-sized apertures. This allows the lower portion of the reflector to have formed therein a wider-diameter aperture to allow for increased current injection. The upper portion of the reflector has formed therein a narrower-diameter, mode-selecting aperture to allow higher-order modes to be reduced, leading to single-mode operation. The VCSELs are thus capable of higher-power emission in a single mode, allowing for longer-distance signaling over optical fiber, despite modal dispersion within the fiber and/or at the coupling between the VCSEL and the fiber. The two differently-sized apertures can be formed via respective lateral oxidation processes following etch-down to form the respective steps of the upper reflector. Differences in composition across the upper reflector results in temperature-dependence of the oxidation process, allowing the apertures to be formed with different sizes.

Narrow beam divergence semiconductor sources are operable to generate a beam having a substantially narrow beam divergence, an emission wavelength, and a substantially uniform beam intensity. The presence of an extended length mirror can help suppress one or more longitudinal and/or transverse modes such that the beam divergence and/or the spectral width of emission is substantially reduced.

A low noise, single mode laser includes a semiconductor gain element generating light and having a highly reflective first end forming a first end of a laser cavity. The gain element may be monolithically or discretely integrated with, or distinct from, and coupled to a waveguide comprised of a low loss material with a refractive index n greater than 3. The waveguide includes a Bragg grating forming the second end of the laser cavity. A cavity phase control section may be provided between the gain element and the Bragg grating. Two photodetector monitors provide a feedback signal for locking the light from the gain element to a specific wavelength on the Bragg grating reflection spectrum by varying at least one of the cavity phase control section and the gain element bias current. The Bragg grating may have a physical length larger than 10 mm and that occupies at least 50% of the optical length of the external cavity.

A laser including: a gain chip; an external cavity incorporating a Bragg grating; and a baseplate; wherein a first end of the gain chip has a high reflectivity facet forming a first end of the laser cavity; a second end of the gain chip has a low reflectivity facet; and a second part of the external cavity comprises a Bragg grating, supported by the baseplate, the temperature of the baseplate being maintained through a feedback loop; wherein the optical length of the external cavity is at least an order of magnitude greater than the optical length of the gain chip; wherein the Bragg grating is physically long and occupies a majority of the length of the external cavity and is apodized to control the sidemodes of the grating reflection.