Example vertical cavity surface emitting lasers (VCSELs) include a mesa structure disposed on a substrate, the mesa structure including a first reflector, a second reflector defining at least one diameter, and an active cavity material structure disposed between the first and second reflectors; and a second contact layer disposed at least in part on top of the mesa structure and defining a physical emission aperture having a physical emission aperture diameter. The ratio of the physical emission aperture diameter to the at least one diameter is greater than or approximately 0.172 and/or the ratio of the physical emission aperture diameter to the at least one diameter is less than or approximately 0.36. An example VCSEL includes a substrate; a buffer layer disposed on a portion of the substrate; and an emission structure disposed on the buffer layer.

A laser diode apparatus has a first waveguide layer including a gain region connected in series with a second waveguide layer with a second gain region. A tunnel junction is positioned between the first and second guide layers. A single collimator is positioned in an output path of laser beams emitted from the first and second waveguide layers. The optical beam from the single collimator may be coupled into an optical fiber.

A monolithic edge emitting semiconductor laser comprising multiple laser diodes using aluminum indium gallium arsenide phosphide AlInGaAs/InGaAsP/InP material system, emitting in long wavelengths (1250 nm to 1720 nm). Each laser diode contains an active region comprising aluminium indium gallium arsenide quantum wells (AlInGaAs QW) and aluminum indium gallium arsenide (AlInGaAs) barriers and is connected to the subsequent monolithic laser diode by highly doped, low bandgap and low resistive indium gallium arsenide junction called tunnel junction.

A method of fabricating a gain medium includes growing a p-type layer doped with zinc on a substrate, growing an undoped layer including one or both of InP or InGaAsP on the p-type layer, growing a region that includes multiple quantum wells (MQWs) on the undoped layer, and growing an n-type layer on the region. The undoped layer has a thickness that is sufficient to prevent Zn diffusion from the p-type layer into the region during subsequent growth or wafer fabrication steps.

Described herein are photonic integrated circuits (PICs) comprising a semiconductor optical amplifier (SOA) to output a signal comprising a plurality of wavelengths, a sensor to detect data associated with a power value of each wavelength of the output signal of the SOA, a filter to filter power values of one or more of the wavelengths of the output signal of the SOA, and control circuitry to control the filter to reduce a difference between a pre-determined power value of each filtered wavelength of the output signal of the SOA and the detected power value of each filtered wavelength of the output signal of the SOA.

A semiconductor light-emitting element having a structure in which a substrate, a first reflector, a resonator cavity including an active layer, a second reflector and a tunnel junction portion are stacked in this sequence, comprising: a first current constriction portion configured with an oxidation constriction layer; and a second current constriction portion including the tunnel junction portion, wherein a width d2 of the second current constriction portion is smaller than a width d1 of the first current constriction portion.

Disclosed herein are self-mixing interferometry (SMI) sensors, such as may include vertical cavity surface emitting laser (VCSEL) diodes and resonance cavity photodetectors (RCPDs). Structures for the VCSEL diodes and RCPDs are disclosed. In some embodiments, a VCSEL diode and an RCPD are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate. In some embodiments, a first and a second VCSEL diode are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate, and an RCPD is formed on the second VCSEL diode. In some embodiments, a VCSEL diode may include two quantum well layers, with a tunnel junction layer between them. In some embodiments, an RCPD may be vertically integrated with a VCSEL diode.

A light emitting device includes: a base comprising a first wiring, a second wiring, and a third wiring; a first semiconductor laser element electrically connected to the first wiring and the second wiring, at an upper surface side of the base; a second semiconductor laser element electrically connected to the second wiring and the third wiring, at the upper surface side of the base; and a base cap fixed to the base such that the first semiconductor laser element and the second semiconductor laser element are enclosed in a space defined by the base and the base cap. The first semiconductor laser element and the second semiconductor laser element are connected in series. A portion of each of the first, second, and third wirings is exposed at the upper surface of the base at locations outside of the space defined by the base and the base cap.

A Vertical Cavity Surface Emitting Laser (VCSEL) including a light emitting III-nitride active region including quantum wells (QWs), wherein each of the quantum wells have a thickness of more than 8 nm, a cavity length of at least 7 λ, or at least 20 λ, where lambda is a peak wavelength of the light emitted from the active region, layers with reduced surface roughness, a tunnel junction intracavity contact. The VCSEL is flip chip bonded using In—Au bonding. This is the first report of a VCSEL capable of continuous wave operation.

An optoelectronic semiconductor device includes a semiconductor body in which an active layer configured to generate or detect electromagnetic radiation, a first interlayer and a p-conducting contact layer are formed, and a connection layer applied to the semiconductor body, wherein the contact layer is disposed between the first interlayer and the connection layer and adjoins the connection layer, the active layer is arranged on a side of the first interlayer remote from the contact layer, the first interlayer and the contact layer are based on a nitride compound semiconductor, the contact layer is doped with a p-dopant, the contact layer has a thickness of at most 50 nm, and the contact layer includes a lower aluminum content than the first interlayer.