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 constructed. The…

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:

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:

LLNL researchers has developed designs to augment WBG/UWBG-based OALVs to improve their power handling capability under CW operational environments.  These designs include:

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.

The approach is to leverage the fact that a momentary “load” equal to the power transmission line impedance, (Z0), during the transient can suppress its propagation.  Z(0) is typically a fixed impedance of several hundred ohms based on the geometry of most single wire transmission lines.

So, an isolated self-powered opticondistor (OTV) system may provide an ultrafast method of…

LLNL’s novel approach is to use diamond substrates with the desired donor (nitrogen) and acceptor (boron) impurities.   In order to optically activate these deep impurities, the invention requires at least one externally or internally integrated light source.  The initial exposure to light can set up the desired conduction current, after which the light source could be turned off.  Even with…

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 incident multi…

Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength.  The diamond material is chosen to be doped with substitutional nitrogen to 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 bandgap (UWBG)…

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)…

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…

LLNL’s Optically-based Interstory Drift Meter System provides a means to accurately measure the dynamic interstory drift of a vibrating building (or other structure) during earthquake shaking. This technology addresses many of the shortcomings associated with traditional strong motion accelerometer based building monitoring.

LLNL’s discrete diode position sensitive device is a newly…

The invention relates to a measurement method and system for capturing both the amplitude and phase temporal profile of a transient waveform or a selected number of consecutive waveforms having bandwidths of up to about 10 THz in a single shot or in a high repetition rate mode. The invention consists of an optical preprocessor which can then output a time-scaled replica of the input signal to…