The approach is to use appropriately doped semi-insulating gallium nitride to provide a high damage tolerant photoconductor with high responsivity to various pump wavelength light. Mn, C, or Fe are used as dopants to provide a source of electrons or holes that can be excited. This is combined with the use of dichroic antireflection coating at the GaN/polyimide/liquid crystal…
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Powder atomic layer deposition process is used to coat nanopowders of host materials (e.g. yttrium aluminum garnet) with optically active neodymium organometal precursor followed by O2/O3 RF plasma to convert to a single layer of Nd2O3. The process can be repeated to build arbitrarily thick layers with custom doping profiles and followed by post-…
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This invention proposes using a pulse laser configured to generate laser pulses and a controller for controlling operation of the pulse laser. The controller is further configured to control the pulse laser to cause the pulse laser to generate at least one of the laser pulses with a spatiotemporally varying laser fluence over a duration of at least one of the laser pulses. The spatiotemporally…
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LLNL researchers has developed designs to augment WBG/UWBG-based OALVs to improve their power handling capability under CW operational environments. These designs include:
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The approach is to build a high voltage insulator consisting of two materials: Poly-Ether-Ether-Ketone (“PEEK”) and Machinable Ceramic (“MACOR”). PEEK has a high stress tolerance but cannot withstand high temperatures, while MACOR has high heat tolerance but is difficult to machine and can be brittle. MACOR is used for the plasma-facing surface, while PEEK will handle the…
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Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength. The diamond material is specifically doped with substitutional nitrogen, which act as a source of electrons. The device architecture allows maximum light entering the aperture. The top and bottom electrodes are made of ultra wide band…
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The approach is to use a custom-designed frustrum and attach it to the optical fiber that connects to the PCSS. Light from the fiber enters the frustrum, spreads out, and enters the PCSS. Any unabsorbed light re-enters the frustrum and, because of its geometry, reflects back into the PCSS itself with only a negligible fraction escaping from the fiber. The shape of the novel…
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LLNL’s approach is to use their patented Photoconductive Charge Trapping Apparatus (U.S. Patent No. 11,366,401) as the active switch needed to discharge voltage across a vacuum gap in a particle accelerator, like the one described in their other patent (U.S. Patent No.
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Livermore Lab researchers have developed two new methods for improving the efficiency of laser drilling. The first method is based on multi-pulse laser technology. Two synchronized free-running laser pulses from a tandem-head Nd:YAG laser and a gated CW laser are capable of drilling through 1/8-in-thick stainless-steel targets at a standoff distance of 1 m without gas-assist. The combination of a…
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The Optical Transconductance Varistor (OTV, formerly Opticondistor) overcomes depletion region voltage limitations by optically exciting wide bandgap materials in a compact package. A 100μm thick crystal could have the capability approaching 40kV and would replace numerous equivalent junction devices. Thus, unlike present junction transistors or diodes, this wide bandgap device can be stacked…
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The new LLNL technique works by transiently removing and trapping concrete or rock surface material, so that contaminants are confined in a manner that is easy to isolate and remove. Our studies suggest that 10 m2 of surface could be processed per hour. The technique easily scales to more surface/hr.