This LLNL invention is a wide bandgap (WBG) or ultra-wide bandgap (UWBG) material comprising a PCSS that is modified, either chemically through alloying and/or mechanically through strain fields, in order to tune the energetic positions of the valence and/or conduction bands and the associated optical transition energies that create and quench the PCSS responsivity.

A thyristor will stay conducting until the current through the device is zero (“current zero”) or perhaps slightly negative.  LLNL’s approach is to use the opticondistor (“OTV”) to force this current zero in order to force the device into an “off” state.  By combining a light-activated thyristor with an OTV, a noise-immune, high efficiency, high-power switching device can be…

The researchers’ approach leverages the concept that dopants have high diffusivities in Ga2O3; the key lies in the selection of the appropriate dopant.  This LLNL invention describes two device types that employ this design:

Rapid monolith development at scale is achieved through use of a functionally equivalent optic simulant made from a low-cost material to substitute the functional optic. Monolith optical performance is affected not only by thermal expansion but also by temperature inhomogeneity due to the temperature dependence of refractive index.

Aeroptics are a proposed new class of monolithic optical system in aerogel fabricated by molding around a master mandrel. This approach combines the intrinsic stability of proven monolithic telescopes, with the ultralow density of silica aerogels. In Aeroptics, the monolith is hollow with an aerogel substrate providing a supporting structure. Theoretically, Aeroptics could enable 1-m aperture…

Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength. 

Characteristics of the LLNL-developed switch are as follows:

This invention achieves both a wider field of view and faster f-number within a monolithic substrate by incorporating an aspheric convex refractive first surface and a planar aspheric field corrector surface on the final refractive surface. These two refractive surfaces work in conjunction with a concave aspheric primary and convex aspheric secondary mirror (e.g. Cassegrain type) to improve…

LLNL researchers have invented an ultrafast PCSS to drive a high-power laser diode with arbitrary pulse widths.  These devices operate by supplying a high voltage (>10 kV) to one side of the switch.  A short pulse of light illuminates the semiconductor, instantly turning it from highly resistive to highly conductive. Ultrawide bandgap (UWBG) semiconductors are used to achieve sub-…

U.S. Patent No. 11,555,965 describes LLNL’s invention of “Illumination Frustums” for photoconductive switches to capture and “frustrate” the light from leaving the frustum.  LLNL researcher’s latest novel invention, “Twister Oven”, achieves this by encouraging laser light absorption in a photo conductor material.  Light enters the oven twisting and reflecting, making near normal…

LLNL researchers faced this challenge by bridging the gap between VEDs and solid-state electronics (SSE).  Their approach was to create a hybrid vacuum microelectronic device (VMD) architecture that combines the properties of vacuum as the electronic medium and the compact form factor and manufacturing scalability of semiconductor microelectronic chips.

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…

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…

Monolithic Telescopes are a novel implementation of a solid catadioptric design form, instantiated in a monolithic block of fused silica.

LLNL is developing the Space-based Telescopes for Actionable Refinement of Ephemeris (STARE). STARE is a constellation of low cost nano-satellites (less than 5Kg) in low-earth orbit dedicated to the observation of space debris in conjunction with a ground-based infrastructure for maintenance, coordination and data processing. Each nano-satellite in the constellation is capable of recording an…