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…

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-…

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…

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…

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…

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.

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.

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

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…

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.

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…