Abstract: A light-emitting device that includes an LED and a light extraction layer and the method for making the same are disclosed. The LED includes a substrate on which an active layer is sandwiched between a p-type layer and an n-type layer, the active layer generating light in a band of wavelengths about a central wavelength when holes and electrons recombine therein. The n-type layer, active layer, and p-type layer are formed on the substrate. First and second electrodes for providing a potential difference between the p-type layer and the n-type layer are included in the LED. The light extraction layer includes a clear layer of material having a first surface in contact with a surface of the LED and a second surface having light scattering features with dimensions greater than 0.5 times the central wavelength. The material of the clear layer can be polycrystalline or amorphous.

Abstract: A vertical-cavity surface-emitting laser incorporating a supported air gap distributed Bragg reflector is disclosed. The supported air gap DBR includes a regrowth layer of material that provides mechanical support for the original material layers. The supported air gap DBR is fabricated by first growing alternating pairs of a first material and a sacrificial material over a suitable substrate. The layer pairs of the first material and sacrificial material are covered by a suitable dielectric material. The dielectric material is then selectively removed exposing regions of the first material and sacrificial material where selective regrowth of additional material is desired. The selective regrowth of the additional material provides mechanical support for the semiconductor material that remains after a selective etch removal of the sacrificial material.

Abstract: 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.

Abstract: A light-emitting device that includes an LED and a light extraction layer and the method for making the same are disclosed. The LED includes a substrate on which an active layer is sandwiched between a p-type layer and an n-type layer, the active layer generating light in a band of wavelengths about a central wavelength when holes and electrons recombine therein. The n-type layer, active layer, and p-type layer are formed on the substrate. First and second electrodes for providing a potential difference between the p-type layer and the n-type layer are included in the LED. The light extraction layer includes a clear layer of material having a first surface in contact with a surface of the LED and a second surface having light scattering features with dimensions greater than 0.5 times the central wavelength. The material of the clear layer can be polycrystalline or amorphous.

Abstract: An optical isolator for coupling light from a first waveguide to a second waveguide is disclosed. The optical isolator utilizes a resonator coupled to the first and second optical waveguides. The resonator has a resonance at ? for light traveling from the first optical waveguide to the second optical waveguide; however, the resonator does not have a resonance at ? for light traveling from the second waveguide to the first waveguide. The resonator can use a layer of ferromagnetic material in an applied magnetic field. The magnetic field within the ferromagnetic material varies in strength and/or direction over the layer of ferromagnetic material. The magnetic field can be generated by an external magnetic field that varies over the layer of ferromagnetic material. Alternatively, the resonator can include a layer of ferromagnetic metal that overlies a portion of the layer of ferromagnetic material and a constant external magnetic field.

Abstract: A distributed Bragg reflector and a method of fabricating the same incorporates a support for supporting the gaps against collapse. The method includes forming a plurality of alternating structure and sacrificial layers on a substrate. The structure and sacrificial layers are etched into at least one mesa protruding from the substrate. A support layer is formed on the at least one mesa leaving a portion of the structure and sacrificial layers exposed. At least a portion of at least one of the exposed sacrificial layers are etched from between the structure layers to form gaps between the structure layers.

Abstract: 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.

Abstract: The light-emitting device comprises a substrate, an active region and a tunnel junction structure. The substrate comprises gallium arsenide. The active region comprises an n-type spacing layer and a p-type spacing layer. The tunnel junction structure comprises a p-type tunnel junction layer adjacent the p-type spacing layer, an n-type tunnel junction layer and a tunnel junction between the p-type tunnel junction layer and the n-type tunnel junction layer. The p-type tunnel junction layer comprises a layer of a p-type first semiconductor material that includes gallium and arsenic. The n-type tunnel junction layer comprises a layer of an n-type second semiconductor material that includes indium, gallium and phosphorus. The high dopant concentration attainable in the second semiconductor material reduces the width of the depletion region at the tunnel junction and increases the electrostatic field across the tunnel junction, so that the reverse bias at which tunneling occurs is reduced.

Abstract: A distributed Bragg reflector and a method of fabricating the same incorporates a support for supporting the gaps against collapse. The method includes forming a plurality of alternating structure and sacrificial layers on a substrate. The structure and sacrificial layers are etched into at least one mesa protruding from the substrate. A support layer is formed on the at least one mesa leaving a portion of the structure and sacrificial layers exposed. At least a portion of at least one of the exposed sacrificial layers are etched from between the structure layers to form gaps between the structure layers.

Abstract: Light-emitting devices are described. One example of a light-emitting device includes a first barrier layer and a second barrier layer, and a quantum well layer located between the first and second barrier layers. The first and second barrier layers are composed of gallium arsenide, and the quantum well layer is composed of indium gallium arsenide nitride. A first layer is located between the quantum well layer and the first barrier layer. The first layer has a bandgap energy between that of the first barrier layer and that of the quantum well layer. Another example of a light-emitting device includes a quantum well and a carrier capture element adjacent the quantum well. The carrier capture element increases the effective carrier capture cross-section of the quantum well.

Abstract: The disclosed hybrid microlens enables the economical production of large diameter, high numerical aperture refractive microlens by microfabrication. The hybrid microlens has a combination of a refractive microlens formed on a thin layer of high index material such as silicon and a spacer layer of a low index material such as fused silica. Advantages include substantially reduced lens sag, fast etching of the microlens, small wafer stack thickness, large diffraction angle in the low index spacer, large optical beam diameter, high optical performance, and low cost. Also disclosed is a design for substantially reduced optical return signal and small polarization dependent optical loss from an optical fiber which is perpendicular to and butt-coupled to a planar optical surface. This design is to form a small slanted surface on the planar optical surface in the vicinity of the optical fiber core and fill the space between the fiber and the slanted surface with an index-matching optical epoxy.

Abstract: An optoelectronic device such as a vertical cavity surface emitting laser (VCSEL) includes a tunnel junction that conducts a current of holes tunneling into an active region. Tunneling in a selected area of the tunnel junction is disabled to form a current blocking region that confines the current to desired regions. Tunneling can be disabled in the selected area using techniques including but not limited to implanting or diffusing dopants, disrupting crystal structure, or etching to remove part of the tunnel junction.

Abstract: 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.

Abstract: The light-emitting device comprises a substrate, an active region and a tunnel junction structure. The substrate comprises gallium arsenide. The active region comprises an n-type spacing layer and a p-type spacing layer. The tunnel junction structure comprises a p-type tunnel junction layer adjacent the p-type spacing layer, an n-type tunnel junction layer and a tunnel junction between the p-type tunnel junction layer and the n-type tunnel junction layer. The p-type tunnel junction layer comprises a layer of a p-type first semiconductor material that includes gallium and arsenic. The n-type tunnel junction layer comprises a layer of an n-type second semiconductor material that includes indium, gallium and phosphorus. The high dopant concentration attainable in the second semiconductor material reduces the width of the depletion region at the tunnel junction and increases the electrostatic field across the tunnel junction, so that the reverse bias at which tunneling occurs is reduced.

Abstract: Various asymmetric InGaAsN VCSEL structures that are made using an MOCVD process are presented. Use of the asymmetric structure effectively eliminates aluminum contamination of the quantum well active region.

Abstract: Light-emitting devices are described. One example of a light-emitting device includes a first barrier layer and a second barrier layer, and a quantum well layer located between the first and second barrier layers. The first and second barrier layers are composed of gallium arsenide, and the quantum well layer is composed of indium gallium arsenide nitride. A first layer is located between the quantum well layer and the first barrier layer. The first layer has a bandgap energy between that of the first barrier layer and that of the quantum well layer. Another example of a light-emitting device includes a quantum well and a carrier capture element adjacent the quantum well. The carrier capture element increases the effective carrier capture cross-section of the quantum well.

Abstract: 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.

Abstract: A method for making high quality InGaAsN semiconductor devices is presented. The method allows the making of high quality InGaAsN semiconductor devices using a single MOCVD reactor while avoiding aluminum contamination.

Abstract: 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.

Abstract: A method for making high quality InGaAsN semiconductor devices is presented. The method allows the making of high quality InGaAsN semiconductor devices using a single MOCVD reactor while avoiding aluminum contamination.