A Dense Wavelength Division Multiplexing (DWDM) photonic integration circuit (PIC) that implements a DWDM system, such as a transceiver, is described. The DWDM PIC architecture includes photonic devices fully integrating on a single manufacturing platform. The DWDM PIC has a multi-wavelength optical laser, a quantum dot (QD) laser with integrated heterogeneous metal oxide semiconductor (H-MOS) capacitor, integrated on-chip. The multi-wavelength optical laser can be a symmetric comb laser that generates two equal outputs of multi-wavelength light. Alternatively, the DWDM PIC can be designed to interface with a stand-alone multi-wavelength optical laser that is off-chip. In some implementations, the DWDM PIC integrates multiple optimally designed photonic devices, such as a silicon geranium (SiGe) avalanche photodetector (APD), an athermal H-MOS wavelength splitter, a QD photodetector, and a heterogenous grating coupler. Accordingly, fabricating the DWDM PIC includes a unique III-V to silicon bonding process, which is adapted for its use of SiGe APDs.

A light source device includes a substrate and a plurality of laser light sources. The laser light sources each include a submount mounted on the substrate, and a semiconductor laser element mounted on the submount. The laser light sources are individually and independently disposed on the substrate. The laser light sources disposed adjacent to each other and emitting light having an identical wavelength band differ from each other in thermal resistance at a region between the semiconductor laser element and the substrate.

A laser for a distributed fiber sensing system may have a frequency discriminator integrated with the laser. The laser may be an external cavity laser, with at least a portion of the laser cavity on a planar lightwave circuit, which also includes the frequency discriminator.

Exemplary embodiments of the present disclosure include chip-scale laser sources, such as semiconductor laser sources, that produce directional beams with low spatial coherence. The lasing modes are based on the axial orbit in a stable cavity and have good directionality. To reduce the spatial coherence of emission, the number of transverse lasing modes can be increased by fine-tuning the cavity geometry. Decoherence is reached in as little as several nanoseconds. Such rapid decoherence facilitates applications in ultrafast speckle-free full-field imaging.

An optical module includes a housing and an optical element that is disposed in the housing and emits light in the housing, in which a partial area of a surface inside the housing serves as a reduced optical reflection area processed so as to absorb the light and have a rough surface.

A Dense Wavelength Division Multiplexing (DWDM) photonic integration circuit (PIC) that implements a DWDM system, such as a transceiver, is described. The DWDM PIC architecture includes photonic devices fully integrating on a single manufacturing platform. The DWDM PIC has a multi-wavelength optical laser, a quantum dot (QD) laser with integrated heterogeneous metal oxide semiconductor (H-MOS) capacitor, integrated on-chip. The multi-wavelength optical laser can be a symmetric comb laser that generates two equal outputs of multi-wavelength light. Alternatively, the DWDM PIC can be designed to interface with a stand-alone multi-wavelength optical laser that is off-chip. In some implementations, the DWDM PIC integrates multiple optimally designed photonic devices, such as a silicon geranium (SiGe) avalanche photodetector (APD), an athermal H-MOS wavelength splitter, a QD photodetector, and a heterogenous grating coupler. Accordingly, fabricating the DWDM PIC includes a unique III-V to silicon bonding process, which is adapted for its use of SiGe APDs.

A system for intraoral scanning includes a display, a processing unit, and a scanner to generate scan data and viewfinder images of an intraoral cavity. The processing unit is to: receive the scan data and the viewfinder images; generate a 3D model of the intraoral cavity using the intraoral scan data; output the 3D model to the display; output the viewfinder images to the display; determine which portions of the intraoral cavity have been scanned; determine a current field of view of the scanner; determine, based on the current field of view and the determined portions of the intraoral cavity that have been scanned, a visual indicator that provides guidance for positioning and orienting the field of view of the scanner; and output the visual indicator to the display.

Examples disclosed herein relate to multi-wavelength semiconductor lasers. In some examples disclosed herein, a multi-wavelength semiconductor laser may include a silicon-on-insulator (SOI) substrate and a quantum dot (QD) layer above the SOI substrate. The QD layer may include and active gain region and may have at least one angled junction at one end of the QD layer. The SOI substrate may include a waveguide in an upper silicon layer and a mode converter to facilitate optical coupling of a lasing mode to the waveguide.

An apparatus comprises an optical cavity formed on a substrate and defining a round-trip optical path, an interface positioning at least a portion of a gain medium to provide an active portion of the round-trip optical path over which the gain medium provides sufficient gain for the optical wave to propagate around the round-trip optical path in a single mode, an output coupler coupling a portion of the optical wave out of the optical cavity from a passive portion of the round-trip optical path into a waveguide segment formed on the substrate, one or more tap couplers each diverting less than 50% of optical power from the waveguide segment, and one or more on-chip modules each receiving diverted optical power from at least one of the tap couplers and providing information associated with a laser that comprises the optical cavity and the gain medium.

Methods and apparatus for measuring objects comprise a plurality of light sources to generate a plurality of light beams directed toward a spot generator array comprising a plurality of spot generating lenses. The plurality of light sources is separated from the spot generator array with a separation distance sufficient to overlap the plurality of light beams at each of the spot generating lenses. The overlap of each of the beams at each of the spot generating lenses provides smoothing of the energy profile of the light energy incident on the spot generating lenses. The spot generator array generates focused spots comprising overlapping focused beams. The overlapping beams may comprise overlapping beams of a vertical cavity surface emitting laser (VCSEL) array, and the overlapping focused beams can decrease optical artifacts.