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This invention proposes achieving the same effect of a single, high intensity pulse through the use of a closely spaced burst of short duration pulses. By keeping the intensity of the individual pulses below the damage threshold the risk of catastrophic damage is greatly mitigated. Additionally, the pulses are directed to strike the target at locations temporally and spatially sufficiently…

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Left to right: Drew Willard, Brendan Reagan, and Issa Tamer work on the Tm:YLF laser system. Photos by Jason Laurea

This invention proposes the use of a nonlinear spectral broadening subsystem as a post-CPA pulse compression add-on for high energy laser systems. The proposed solution utilizes the beam profile of a high peak power laser as a reference to shape a highly transmissive nonlinear plastic (e.g., CR39) itself to ensure a spatially homogeneous nonlinear spectral broadening.

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Adobe Stock image laser beam

This invention proposes to engineer the current density along the length of a laser diode to overcome the penalty associated with non-uniformity resulting from asymmetry in the gain, photon or carrier density despite having uniform contact. Optimizing the current density profile enables diode lasers to operate with greater power conversion efficiency or operate with equivalent power conversion…

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Schematic showing mismatched coefficient of thermal expansion (CTE) coating

This invention proposes to engineer the temperature dependence of the emission wavelength of LEDs and laser diodes. The approach is to use a strain-inducing coating to counteract the intrinsic temperature coefficient of the emission wavelength of the LED or laser diode device thereby rendering it athermal. This invention avoids additional complexity, size, weight and power dissipation of…

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Photoconductive Semiconductor Laser Diodes and LEDs

This invention proposes a method to overcome the key limitation of electrically pumped lasers based on AlN, AlGaN, or AlInGaN, namely the lack of suitable shallow donor and acceptor dopants. As the band gap of these materials increases (and the emission wavelength decreases), both electrons and holes require greater thermal energies in order to ionize.

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Adobe Stock image laser beam

Laser diode lensing effect can be substantially reduced by creating a pattern interface such that the substrate is only attached at the diode mesa. This is achieved by either creating a pattern solder joint and/or pattern substrate.

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OALV design with High-k Photoconductor and High-k Optical Window

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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Segments of transmission line lengths can be switched to open circuit (as shown) or shorted to the ground (not shown)

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 gap (UWBG)…

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Annular illumination on photo conductor by Conical Total Internal Reflection “CTIR” endcap

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 frustrum is…

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OTV Image

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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Serrated Light Illumination for Deflection-Encoded Recording  (SLIDER)

The SLIDER deflector includes a waveguide, a serrated mask positioned above the waveguide cladding, and a synchronized pump beam. The pump beam illuminates the serrated mask with a short pulse and transfers its pattern to the guiding layer where it imprints a sequence of prisms. The prisms are activated via nonlinear optical effects in the semiconductor and persist for the duration of the…