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.

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.

A Vertical Cavity Surface Emitting Laser (VCSEL) has a mesa having an active region, which has m active layer structures (with m2). The active layer structures are electrically connected to each other by a tunnel junction therebetween. The mesa has an optical resonator, which has first and second DBRs. The active region is between the first and second DBRs. The VCSEL has first and second electrical contacts, which provide electrical current to the active region, and an electrical control contact, which controls gain-switched laser emission of the VCSEL by at least 1 up to m-1 active layer structures by a current between the electrical control contact and the first or second electrical contact. A current aperture is between the active region and the first or second electrode. A distance between the current aperture and a furthest active layer structure is at least three times the laser light's wavelength.

A monolithic laser device assembly 10A in the present disclosure includes a first gain portion 20 having a first end portion 20A and a second end portion 20B, a second gain portion 30 having a third end portion 30A and a fourth end portion 30B, one or multiple ring resonators 40, a semiconductor optical amplifier 50 for amplifying a laser light emitted from the first gain portion 20, and a pulse selector 60 disposed between the first gain portion 20 and the semiconductor optical amplifier 50, in which the ring resonator 40 is optically coupled with the first gain portion 20 and with the second gain portion 30, and laser oscillation is performed on either the first gain portion 20 or the second gain portion 30.

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.

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.

A semiconductor light emitting device includes a microstrip substrate with a single-ended transmission line on a top surface, wherein the single-ended transmission line extends from a first end portion to a second end portion, the microstrip substrate has a ground plane on a bottom surface, and the ground plane is opposed and bonded to the conductive pattern. The single-ended transmission line includes a first section and a second section, wherein the second section extends from the first section and includes the second end portion. The second section is lower in characteristic impedance than the first section. A load circuit that includes the wire, the optical modulator, and the termination resistor is electrically connected between the second end portion and the conductive pattern. The load circuit is equal to or lower in the characteristic impedance than the second section.

An optomechanical laser includes: a basal member; a mechanical transducer; a laser disposed on the mechanical transducer, the laser being displaced along the displacement axis in response to a displacement of the mechanical transducer relative to the basal member; a mirror disposed on the armature in optical communication with the laser and opposing the laser; the armature disposed on the basal member and rigidly connecting the mirror to the basal member such that the mirror and the armature move in synchrony with the basal member, and the armature provides a substantially constant distance between the basal member and the mirror; and a cavity comprising: the laser; the mirror; and a cavity length between the laser and the mirror that changes in response to displacement of the laser according to the displacement of the mechanical transducer relative to the basal member, the optomechanical laser providing laser light.

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.

A solid-state light source (SSLS) with light modulation control is described. A SSLS device can include a main p-n junction region configured for recombination of electron-hole pairs for light emission. A supplementary p-n junction region is proximate the main p-n junction region to supplement the recombination of electron-hole pairs, wherein the supplementary p-n junction region has a smaller electron-hole life time than the electron-hole life time of the main p-n junction region. The main p-n junction region and the supplementary p-n junction region operate cooperatively in a light emission state and a light turn-off-state. In one embodiment, the recombination of electron-hole pairs occurs in the main p-n junction region during a light emission state, and the recombination of electron-hole pairs occurs in the supplementary p-n junction region light during the light turn off-state.