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 printing system is disclosed which comprises a writing module, and a member having an imaging surface configured to carry a polymer and movable relative to the writing module. The writing module is configured to direct onto the imaging surface a plurality of individually controllable light beams that are spaced from one another in a direction transverse to the direction of movement of the imaging surface, incidence of a light beam on a spot on the imaging surface serving to soften or liquefy the polymer carried by the imaging surface at the spot. The polymer softened or liquefied at the spot can transfer to a substrate or serve as an adhesive on the imaging surface. The writing module comprises a plurality of integrated electronic modules each having an array of individually controllable light sources, each light source producing a respective one of the light beams. In the invention, each light source comprises at least two Vertical-Cavity Surface-Emitting Laser (VCSEL) light-emitting semiconductor junctions connected in series with one another and configured to direct light onto the imaging surface at the same spot as one another.

Provided is a vertical cavity surface emitting laser diode (VCSEL) with multiple current confinement layers. A tunnel junction is generally required between two active layers to enable current to flow from one to another active layer. However, the tunnel junction will cause the current to spread in one active layer to become serious. As a result, the current in another active layer is difficult to be confined to the required area. Therefore, a current confinement layer with carrier and optical confinement functions is provided between two active layers such that the carrier and optical confinement of the active layers above and below the current confinement layer can be improved, thereby improving the performance of VCSEL. Compared with the existing VCSEL, the VCSEL with multiple current confinement layers can significantly improve the optical output power, slope efficiency and power conversion efficiency (PCE) of the VCSEL.

Provided is a semiconductor laser diode. Although the materials used in the conventional technology can reduce the strain, the selections of materials are relatively limited and the carrier confinement ability is not good. To solve the above-mentioned problems, a phosphorus-containing semiconductor layer is provided in a laser diode. As such, it can effectively reduce the strain of the active region or the total strain of the laser diode, and improve the carrier confinement capability of the active region. Therefore, it can effectively reduce the total strain or significantly improve carrier confinement under appropriate conditions of the laser diode. In some cases, it has the aforesaid effects. The phosphorus-containing semiconductor layer is suitable for an active region with one or more active layers. Especially after the phosphorus-containing semiconductor layer is provided in the active region with multiple active layers, high temperature performance are significantly improved or enhanced.

External cavity laser systems are described that can operate with essentially no mode hopping. One example configuration of the laser system includes a semiconductor laser device, a folded cavity external to the semiconductor laser device, where at the semiconductor laser device is positioned at a fold in the folded cavity. In this configuration, at least one mirror is positioned in the folded cavity to enable sustained propagation of light within the folded cavity, and at least two polarization elements are positioned in the folded external cavity. The polarization elements cause a polarization state of the light that impinges in different directions on each semiconductor laser device that is positioned at a fold to be orthogonal to one another, thus eliminating or substantially reducing mode hopping in the laser output.

Disclosed is an optically pumped vertical cavity laser structure operating in the mid-infrared region, which has demonstrated room-temperature continuous wave operation. This structure uses a periodic gain active region with type I quantum wells comprised of InGaAsSb, and barrier/cladding regions which provide strong hole confinement and substantial pump absorption. A preferred embodiment includes at least one wafer bonded GaAs-based mirror. Several preferred embodiments also include means for wavelength tuning of mid-IR VCLs as disclosed, including a MEMS-tuning element. This document also includes systems for optical spectroscopy using the VCL as disclosed, including systems for detection concentrations of industrial and environmentally important gases.

A reflector for optical devices is disclosed. The reflector includes a distributed Bragg reflector and a metal reflector. The metal reflector is contained within one or more apertures defined by a material having good adhesion to a semiconductor material. method for bonding the resulting structure to a heat spreader is also disclosed.

A VCSEL device includes a first electrical contact, a substrate, a second electrical contact, and an optical resonator arranged on a first side of the substrate. The optical resonator includes a first reflecting structure comprising a first distributed Bragg reflector, a second reflecting structure comprising a second distributed Bragg reflector, an active layer arranged between the first and second reflecting structures, and a guiding structure. The guiding structure is configured to define a first relative intensity maximum of an intensity distribution within the active layer at a first lateral position such that a first light emitting area is provided, to define at least a second relative intensity maximum of the intensity distribution within the active layer at a second lateral position such that a second light emitting area is provided, and to reduce an intensity in between the at least two light-emitting areas during operation.

Systems and methods disclosed herein include an illumination module for 3D sensing applications. The illumination module may include an array of vertical cavity surface emitting lasers (VCSELs) emitting light, a driver configured to provide current to the array of VCSELs, and an optical element configured to receive the light emitted by the array of VCSELs and output a light pattern from the illumination module.

Embodiments of the present disclosure provide an optical resonant cavity and a display panel. The optical resonant cavity includes a light conversion layer, the optical resonant cavity is configured to emit light with a specific wavelength range, and the light conversion layer is arranged at at least one wave node of a center wavelength of the light with the specific wavelength range in the optical resonant cavity.