A visible light source includes a substrate, a vertical-cavity surface-emitting laser including an active semiconductor region configured to emit infrared light and a first reflector configured to reflect the infrared light emitted by the active semiconductor region, a second reflector configured to reflect the infrared light and form a vertical cavity for the infrared light with the first reflector, and one or more micro-resonators configured to receive the infrared light and generate visible light in one or more colors using the infrared light through optical parametric oscillation. The visible light source also includes one or more output couplers configured to couple the visible light in one or more colors from the one or more micro-resonators into free space or into a photonic integrated circuit.

A vertical cavity surface emitting laser includes a gain layer configured to generate light; a distributed Bragg reflector below the gains layer; and a meta structure reflector above the gain layer and comprising a plurality of nano structures having a sub wavelength dimension.

Disclosed is a single-photon source emitting light with controllable circular polarization direction. A pillar structure above a semiconductor substrate includes a semiconductor single-quantum-dot structure. A spin injection layer is arranged above the pillar structure. A pulsed voltage is applied between the spin injection layer and the semiconductor substrate to inject a spin-polarized single-carrier from the spin injection layer into the semiconductor single-quantum-dot structure. In response to the injected single-carrier, a single-quantum-dot emits a single-photon with a circular polarization direction corresponding to the spin direction of the injected single-carrier. The polarization controllable single-photon source allows to use magnetic or electrical means to modulate the circular polarization direction of single-photon. The modulation speed by electrical mean can reach up to GHz range.

A disclosed surface-emitting laser module includes a surface-emitting laser formed on a substrate to emit light perpendicular to its surface, a package including a recess portion in which the substrate having the surface-emitting laser is arranged, and a transparent substrate arranged to cover the recess portion of the package and the substrate having the surface-emitting laser such that the transparent substrate and the package are connected on a light emitting side of the surface-emitting laser. In the surface-emitting laser module, a high reflectance region and a low reflectance region are formed within a region enclosed by an electrode on an upper part of a mesa of the surface-emitting laser, and the transparent substrate is slanted to the surface of the substrate having the surface-emitting laser in a polarization direction of the light emitted from the surface-emitting laser determined by the high reflectance region and the low reflectance region.

A method of fabricating a radiation emitter including fabricating a layer stack that includes a first reflector, at least one intermediate layer, an active region and a second reflector; locally oxidizing the intermediate layer and thereby forming at least one unoxidized aperture; and locally removing the layer stack, and thereby forming a mesa that includes the first reflector, the unoxidized aperture, the active region, and the second reflector. Before or after locally removing the layer stack and forming the mesa: forming at least a first unoxidized aperture and at least a second unoxidized aperture inside the intermediate layer; etching a trench inside the layer stack, the trench defining a first portion and a second portion of the mesa, wherein the trench severs the intermediate layer(s) so that the first aperture is located in the first portion and the second aperture is located in the second portion of the mesa.

A MEMS tunable VCSEL includes a membrane device having a mirror and a distal-side electrostatic cavity for displacing the mirror to increase a size of an optical cavity. A VCSEL device includes an active region for amplifying light. Then, a proximal-side electrostatic cavity is defined between the VCSEL device and the membrane device is used to displace the mirror to decrease a size of an optical cavity.

A quantum interference device (atomic oscillator) includes: an atom cell that encapsulates an alkali metal; a first light source portion that emits light including a resonance light pair, the resonance light pair being circularly polarized in the same direction and causing the alkali metal to resonate; a second light source portion that emits light including adjustment light, the adjustment light being circularly polarized in a direction opposite to the resonance light pair and causing the alkali metal to resonate; and a light receiving portion that receives the resonance light pair having passed through the atom cell, in which the adjustment light is FM-modulated.

An encoder includes an optical scale that is so provided as to be pivotable around a pivotal axis and includes a polarizing portion having a polarization characteristic, a light outputting portion that outputs linearly polarized light toward the polarizing portion, and a light detecting portion that detects the linearly polarized light from the optical scale. The light outputting portion includes a vertical cavity surface emitting laser, and light emitted from the vertical cavity surface emitting laser spreads at an angle greater than or equal to 5° but smaller than or equal to 20°.

A tunable source includes a short-cavity laser optimized for performance and reliability in SSOCT imaging systems, spectroscopic detection systems, and other types of detection and sensing systems. The short cavity laser has a large free spectral range cavity, fast tuning response and single transverse, longitudinal and polarization mode operation, and includes embodiments for fast and wide tuning, and optimized spectral shaping. Disclosed are both electrical and optical pumping in a MEMS-VCSEL geometry with mirror and gain regions optimized for wide tuning, high output power, and a variety of preferred wavelength ranges; and a semiconductor optical amplifier, combined with the short-cavity laser to produce high-power, spectrally shaped operation. Several preferred imaging and detection systems make use of this tunable source for optimized operation are also disclosed.

A light emitting element comprising a layered structure configured by layering a first light reflecting layer 41 configured by layering a plurality of thin films, a light emitting structure 20, and a second light reflecting layer 42 configured by layering a plurality of thin films, wherein the light emitting structure 20 is configured by layering, from the first light reflecting layer side, a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22, a second electrode 32 and an intermediate layer 70 are formed between the second compound semiconductor layer 22 and the second light reflecting layer 42 from the second compound semiconductor layer side, and the value of a surface roughness of a second surface 72 of the intermediate layer 70 in contact with the second light reflecting layer 42 is less than the value of a surface roughness of a first surface 71 of the intermediate layer 70 facing the second electrode 32.