Abstract: There is provided an electronic device. The electronic device includes at least one epitaxial semiconductor layer disposed on a single crystal substrate comprised of gallium nitride having a dislocation density less than about 105 per cm2. A method of forming an electronic device is also provided. The method includes providing a single crystal substrate comprised of gallium nitride having a dislocation density less than about 105 per cm2, and homoepitaxially forming at least one semiconductor layer on the substrate.

Abstract: A photodetector (100, 200, 300) comprising a gallium nitride substrate, at least one active layer (104, 302) disposed on the substrate (102, 202, 306), and a conductive contact structure (106, 210, 308) affixed to the active layer (104, 302) and, in some embodiments, the substrate (102, 202, 306). The invention includes photodetectors (100, 200, 300) having metal-semiconductor-metal structures, P-i-N structures, and Schottky-barrier structures. The active layers (104, 302) may comprise Ga1-x-yAlxInyN1-z-w PzAsw, or, preferably, Ga1-xAlxN. The gallium nitride substrate comprises a single crystal gallium nitride wafer and has a dislocation density of less than about 105 cm?2. A method of making the photodetector (100, 200, 300) is also disclosed.

Abstract: A technique for detecting defects in aircraft wiring, such as for detecting partial discharges or arcing in wiring or cables is disclosed. A high frequency current transformer (HFCT) is fixingly positioned in contact with a wire so that the wire is encircled by the HFCT. Partial discharges from a damaged wire so encircled will induce a current in the HFCT proportional to the current of the discharge. The HFCT includes a conductive coil-like pattern formed onto a flexible insulating material. The insulating material has slits between each coil-turn. The HFCT also includes a core of flexible material fitted between the coil-turns through the slits.

Abstract: A cable, system and method for detecting partial discharges or arcing in wiring or cables via fiber optics are provided. The cable for detecting partial discharges includes a conductor for carrying electrical signals; at least one fluorescent optical fiber for detecting light generated by a partial discharge; and a first transparent layer surrounding the conductor for supporting the at least one fluorescent optical fiber generally parallel to the conductor. By employing a fluorescent optical fiber, incident light generated by a partial discharge along a length of the optical fiber will be transmitted via the optical fiber to an optical receiver for determining a partial discharge has occurred.

Abstract: A light emitting device, such as a light emitting diode or a laser diode. The light emitting device comprises a light emitting semiconductor active region disposed on a substrate. The substrate comprises an optical absorption coefficient below about 100 cm?1 at wavelengths between 700 and 465 nm a GaN single crystal having a dislocation density of less than 104 per cm2 and an optical absorption coefficient below about 100 cm?1 at wavelengths between 700 and 465 nm. A method of making such a light emitting device is also provided.

Abstract: A system and method for detecting partial discharges or arcing in wiring or cables is disclosed. The system employs a high-voltage AC power source to generate a high-voltage low-current AC waveform, which is propagated through a selected wire, which in turn, produces the return signal. The return signal is processed using a signal processor and the analyzed for indications of the occurrence of a partial discharge. The method detects damage to a selected wire by utilizing high voltage, low current AC waveforms to induce partial discharges in a controlled manner and detecting a return signal resulting from the discharge.

Abstract: A light emitting device, such as a light emitting diode or a laser diode. The light emitting device comprises a light emitting semiconductor active region disposed on a substrate. The substrate comprises an optical absorption coefficient below about 100 cm−1 at wavelengths between 700 and 465 nm a GaN single crystal having a dislocation density of less than 104 per cm2 and an optical absorption coefficient below about 100 cm−1 at wavelengths between 700 and 465 nm. A method of making such a light emitting device is also provided.

Abstract: A photodetector comprising a gallium nitride substrate, at least one active layer disposed on the substrate, and a conductive contact structure affixed to the active layer and, in some embodiments, the substrate. The invention includes photodetectors having metal-semiconductor-metal structures, P-i-N structures, and Schottky-barrier structures. The active layers may comprise Ga1−x−yAlxInyN1−z−wPzAsw, or, preferably, Ga1−xAlxN. The gallium nitride substrate comprises a single crystal gallium nitride wafer and has a dislocation density of less than about 105 cm−2. A method of making the photodetector is also disclosed.

Abstract: There is provided an electronic device. The electronic device includes at least one epitaxial semiconductor layer disposed on a single crystal substrate comprised of gallium nitride having a dislocation density less than about 105 per cm2. A method of forming an electronic device is also provided. The method includes providing a single crystal substrate comprised of gallium nitride having a dislocation density less than about 105 per cm2, and homoepitaxially forming at least one semiconductor layer on the substrate.

Abstract: A photodetector comprising a gallium nitride substrate, at least one active layer disposed on the substrate, and a conductive contact structure affixed to the active layer and, in some embodiments, the substrate. The invention includes photodetectors having metal-semiconductor-metal structures, P-i-N structures, and Schottky-barrier structures. The active layers may comprise Ga1-x-yAlxInyN1-z-wPzAsw, or, preferably, Ga1-xAlxN. The gallium nitride substrate comprises a single crystal gallium nitride wafer and has a dislocation density of less than about 105 cm−2. A method of making the photodetector is also disclosed.