摘要:
A method for high-volume production of light emitting diodes with attached lenses involves providing pre-fabricated lenses, wherein the pre-fabricated lenses are held by a common transfer structure, simultaneously attaching the pre-fabricated lenses to respective ones of light emitting diodes, and releasing the pre-fabricated lenses from the common transfer structure. In an embodiment, the light emitting diodes are distributed in a pattern on a common substrate and the common transfer structure is configured to hold the pre-fabricated lenses in a pattern that corresponds to the pattern of the light emitting diodes on the common substrate. Further, to attach the pre-fabricated lenses to the light emitting diodes, the common transfer structure is positioned relative to the common substrate such that the pre-fabricated lenses are aligned with the light emitting diodes.
摘要:
The tunnel junction structure comprises a p-type tunnel junction layer of a first semiconductor material, an n-type tunnel junction layer of a second semiconductor material and a tunnel junction between the tunnel junction layers. At least one of the semiconductor materials includes gallium (Ga), arsenic (As) and either nitrogen (N) or antimony (Sb). The probability of tunneling is significantly increased, and the voltage drop across the tunnel junction is consequently decreased, by forming the tunnel junction structure of materials having a reduced difference between the valence band energy of the material of the p-type tunnel junction layer and the conduction band energy of the n-type tunnel junction layer.
摘要:
An optical assembly includes an optical subassembly containing a prefabricated long wavelength laser optically coupled to a prefabricated short wavelength laser located in a housing. The optical subassembly may be removably installed in the housing in which the short wavelength laser is contained. The short wavelength laser optically pumps the long wavelength laser resulting in a long wavelength laser output. The optical subassembly allows the independent fabrication, optimization and testing of the short wavelength laser and the long wavelength laser.
摘要:
A VCSEL that is adapted to the fabrication of an array of VCSELs. A VCSEL array according to the present invention includes first and second VCSELs for generating light of a predetermined wavelength. Each VCSEL includes a bottom reflector comprising an epitaxial layer of a semiconductor of a first conductivity type, a light generation region and a top reflector comprising a semiconductor of a second conductivity type. A bottom electrode is electrically connected to the bottom reflector, and a top electrode is electrically connected to the top reflector. The bottom electrode is grown on top of a buffer layer having an electrical conductivity less than a predetermined value and a crystalline structure that permits epitaxial growth of the bottom reflector on the buffer layer. The buffer layer may be grown on top of a substrate or be the substrate itself in the case in which a substrate having sufficiently low conductivity is utilized. The bottom reflector of each of the VCSELs is in contact with the top of the buffer layer. The first and second VCSELs are electrically isolated from one another by a trench extending into the buffer layer. The buffer layer is constructed from a material having resistivity that is sufficiently low to prevent cross-talk between the first and second VCSELs.
摘要:
A substantially n-type substrate structure having a p-type surface for use in semiconductor devices as a substitute for a p-type semiconductor substrate. The substrate structure comprises a substrate region and a buffer region. The substrate region is a region of n-type compound semiconductor, and includes a degeneratively n-doped portion adjacent its first surface. The buffer region is a region of compound semiconductor doped with a p-type dopant. The buffer region is located on the first surface of the substrate region and includes a surface remote from the substrate region that provides the p-type surface of the substrate structure. The buffer region also includes a degeneratively p-doped portion adjacent the degeneratively n-doped portion of the substrate region. The substrate structure includes a tunnel junction between the degeneratively n-doped portion of the substrate region and the degeneratively p-doped portion of the buffer region. The substrate structure is made by degeneratively doping a substrate region of n-type compound semiconductor material adjacent its first surface with an n-type impurity, and depositing a layer of compound semiconductor material doped with a p-type impurity on the first surface of the substrate region to form a buffer region that includes a surface remote from the substrate region. In the course of depositing the compound semiconductor material to form the buffer region, the compound semiconductor material is degeneratively doped with the p-type impurity at least in a portion adjacent the substrate region to form a tunnel junction between the substrate region and the buffer region.
摘要:
A surface emitting laser diode device is disclosed where an active layer is implanted with oxygen ions except for a small active region. The active region includes a pn junction for generating radiation in response to passage of electrical current therethrough. After the oxygen implantation, mirror layers are grown on top of the active layer to reflect light generated in the active region back into the active region to induce more radiation emission. Mirror layers are also provided underneath the active region for the same purpose. Contact layers are provided on the top and bottom of the structure just described so that when an electrical potential is applied between the two contacts, electrical current will flow between the contacts between the active region for generating radiation. The oxygen-implanted isolation region surrounds the active region in order to confine current flow to the active region.
摘要:
A light emitting diode (100 or 150) includes a diode structure containing a quantum well (120), an enhancement layer (142), and a barrier layer (144 or 148) between the enhancement layer (142) and the quantum well (120). The enhancement layer (142) supports plasmon oscillations at a frequency that couples to photons produced by combination of electrons and holes in the quantum well (120). The barrier layer serves to block diffusion between the enhancement layer (142) and the diode structure.
摘要:
A light generating device such as a VCSEL includes a light generation layer, a top reflector, a bottom reflector, and a high thermal conductivity (HTC) layer between the light generation layer and the bottom reflector. The light generation layer is adapted to generate light having a first wavelength. Heat produced at the light generation layer is more efficiently dissipated due to the presence of the HTC layer. Alternatively, a light generating device such as a VCSEL includes a light generation layer, a top reflector, and a high thermal conductivity (HTC) bottom reflector. Heat produced at the light generation layer is more efficiently dissipated due to the fact that the bottom reflector is a HTC DBR reflector having lower thermal resistivity than a conventional DBR reflector.
摘要:
Subwells are added to quantum wells of light emitting semiconductor structures to shift their emission wavelengths to longer wavelengths. Typical applications of the invention are to InGaAs, InGaAsSb, InP and GaN material systems, for example.
摘要:
A method and apparatus is provided for improving the temperature performance of GaAsSb materials utilizing an AlGaInP confinement structure. An active region containing a GaAsSb quantum well layer and (In)GaAs barrier layers is sandwiched between two AlGaInP confinement layers. AlGaInP confinement structures provide sufficient electron confinement, thereby improving the stability of the threshold current with respect to increasing temperature for GaAsSb/GaAs heterostructures.