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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This invention works by imaging an ultrafast pulse diffracted from a large grating onto a spatial light modulator (SLM) thereby directly transcribing an arbitrary record on a pulse front tilted (PFT) ultrafast pulse. The grating generates PFT of the input pulse, and the SLM provides temporal control of the pulse through the space-to-time mapping of the tilted pulse. Coupling this patterned…
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This invention exploits the non-linearities of optical Mach-Zehnder (MZ) electrooptic modulators to enhance small signal dynamic range at higher bandwidths. A linear photodiode (PD) converts the amplified optical signal output from the MZ back to an electrical signal completing an Electrical-Optical-Electrical (EOE) conversion cycle. The dynamic range can be further enhanced by daisy chaining…
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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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To address the need for realistic and high-fidelity first responder training, a multidisciplinary team at LLNL has worked to establish the new gold standard simulator called TARANTULA (Tactical Augmented Reality Applications for Nuclear Emergency Support Team (NEST) Training using Livermore Analytics). TARANTULA is a scientifically accurate, fully functional, field-deployable simulator that…
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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 researchers in the NIF Directorate DoD Technologies RF Photonics Group explored phase modulation solutions to this signal processing challenge. Optical frequency combs offer phase noise characteristics that are orders of magnitude lower than available from commercial microwave references. The Photonics Group researchers recognized that by converting the intensity information into phase,…
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There are three main components to the RaFTS system: 1) the radiation detector, which can be of any type and from any manufacturer; 2) the RaFTS electronics, which produce the electronic pulses that are injected into the electronics of the radiation detector through a (to be) standardized port interface; and 3) the exercise scenario, which defines the synthetic radiation field and time-varying…
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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…