The invention relates to coherent single photon sources that provide photons with a high degree of indistinguishability. It is a disadvantage of single photon sources based on QDs in nanophotonic structures that, even at low temperatures, acoustic vibrations interact with the QDs to reduce the coherence of the emitted spectrum. The invention uses mechanical clamping of the nanostructure to damp vibrations leading to a weaker QD—phonon coupling and a higher degree of indistinguishability between successively emitted photons. The clamp is mechanically connected to the length of the photonic nanostructure and has a stiffness and a size sufficient to suppress low frequency vibrations (ω≤10 GHz) in a combined structure of the clamp and the nanostructure.

A single-mode micro-laser based on a single whispering gallery mode optical microcavity and a preparation method thereof described includes: preparing a desired single whispering gallery mode optical microcavity doped with rare earth ions or containing a gain material such as quantum dots, wherein an optical microcavity configuration include a micro-disk cavity, a ring-shaped microcavity, and a racetrack-shaped microcavity; a material type include lithium niobate, silicon dioxide, silicon nitride, etc.; preparing an optical fiber cone or an optical waveguide of a required size which can excite high-order modes of the optical microcavity, such as a ridge waveguide and a circular waveguides; and coupling, integrating, and packaging the optical fiber cone or the optical waveguide with the microcavity. A pump light is coupled to the optical fiber cone or the optical waveguide to excite a compound mode with a polygonal configuration.

In one embodiment, a nanobeam cavity device includes an elongated waveguide having a central optical cavity, first and second lateral substrates that are positioned on opposed lateral sides of the waveguide, and carrier-injection beams that extend from the first and second lateral substrates to the central optical cavity of the elongated waveguide.

A tunable laser for a transceiver includes a silicon photonics substrate, first and second patterned regions each being defined in the substrate a step lower than a flat surface region of the substrate, first and second laser diode chips arranged in the first and second patterned regions, the patterned regions being configured to align the gain regions of the first and second laser diode chips with integrated couplers formed in the substrate adjacent to the first and second patterned regions to facilitate flip-bonding the first and second laser diode chips within the patterned regions, and a tuning filter coupled to the first laser diode chip and the second laser diode chip via the integrated couplers. The tuning filter is configured to receive laser light from each of the first and second laser diode chips and generate a laser output having a gain determined by each of the gain regions.

The disclosure provides a nanolaser based on a depth-subwavelength graphene-dielectric hyperbolic dispersive cavity, comprising a pumping light source and the depth-subwavelength graphene-dielectric hyperbolic dispersive cavity; wherein the depth-subwavelength graphene-dielectric hyperbolic dispersive cavity is a spherical or hemispherical hyperbolic dispersive microcavity formed by alternately wrapping a dielectric core with graphene layers and dielectric layers. Because the graphene plasmon has unique excellent performances, such as an electrical adjustability, a low intrinsic loss, a high optical field localization, and a continuously adjustable resonance frequency from mid-infrared to terahertz, compared with a common metal-dielectric hyperbolic dispersive characteristic, a graphene-dielectric hyperbolic dispersive metamaterial used by the disclosure not only may highly localize an energy of an electromagnetic wave in a more depth-subwavelength cavity, but also may reduce an ohmic loss and improve a quality factor.

A structure includes a semiconductor support, a semiconductor region overlying the semiconductor support, a silicon nitride layer surrounding and straining the semiconductor region, and a metal foot separating the silicon nitride layer from the semiconductor support. The semiconductor region includes germanium. The semiconductor region can be a resonator of a laser or a waveguide.

A light-emitting device including a substrate, a plurality of column portions each including a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, and a light-emitting layer provided between the first semiconductor layer and the second semiconductor layer, an electrode including a first electrode layer electrically coupled to the second semiconductor layer of each of the plurality of column portions, and a second electrode layer provided on an opposite side of the first electrode layer from the substrate and having an electrical resistivity lower than an electrical resistivity of the first electrode layer, wherein the first electrode layer includes a first portion in contact with the second electrode layer on the opposite side from the substrate, and a second portion not in contact with the second electrode layer on the opposite side from the substrate and having a greater thickness than the first portion.

A light-emitting device includes a substrate, a laminated structure having a plurality of column portions, and an electrode provided on a side of the laminated structure opposite to the substrate. Each of the plurality of column portions includes a light-emitting layer. The electrode is provided with a plurality of first holes. The plurality of column portions form a first photonic crystal. The electrode forms a second photonic crystal. The first photonic crystal and the second photonic crystal are optically coupled to each other.

GaN-based nanowire heterostructures have been intensively studied for applications in light emitting diodes (LEDs), lasers, solar cells and solar fuel devices. Surface charge properties play a dominant role on the device performance and have been addressed within the prior art by use of a relatively thick large bandgap AlGaN shell covering the surfaces of axial InGaN nanowire LED heterostructures has been explored and shown substantial promise in reducing surface recombination leading to improved carrier injection efficiency and output power. However, these lead to increased complexity in device design, growth and fabrication processes thereby reducing yield/performance and increasing costs for devices. Accordingly, there are taught self-organising InGaN/AlGaN core-shell quaternary nanowire heterostructures wherein the In-rich core and Al-rich shell spontaneously form during the growth process.

The present invention relates to a single photon source, comprising: a microcavity arranged between a concave first minor and a semiconductor heterostructure forming a planar second minor, wherein the microcavity supports an optical mode, a quantum dot embedded in the semiconductor heterostructure and facing the first minor, and a laser light source configured to provide laser light in the microcavity to excite the quantum dot to emit single photons exiting the microcavity.