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…
Keywords
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- Imaging Systems (9)
- Photoconductive Semiconductor Switches (PCSS) (9)
- Semiconductors (6)
- Compact Space Telescopes (5)
- Laser Materials Processing (5)
- Sensors (4)
- Optical Damage Mitigation (3)
- Power Electronics (3)
- Precision Optical Finishing (3)
- RF Photonics (3)
- Ultrashort Pulse Lasers (3)
- Computing (2)
- Electric Grid (2)
- MEMS Sensors (2)
- Particle Accelerators (2)
- Precision Engineering (2)
- Spectrometers (2)
- (-) Diode Lasers (4)
- (-) Optical Switches (4)
- (-) Optical Sensors (2)
Technology Portfolios
![Schematic showing mismatched coefficient of thermal expansion (CTE) coating](/sites/default/files/styles/scale_exact_400x400_/public/2024-02/IL-13312_Schematic.png?itok=5MN8Mf-U)
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…
![Photoconductive Semiconductor Laser Diodes and LEDs](/sites/default/files/styles/scale_exact_400x400_/public/2024-02/Photoconductive%20Semiconductor%20Laser%20Diodes%20and%20LEDs.png?itok=n50p3rOY)
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.
![Adobe Stock image laser beam](/sites/default/files/styles/scale_exact_400x400_/public/2024-02/stockimage_laserbeam.png?itok=U06HtIhR)
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.
![OALV design with High-k Photoconductor and High-k Optical Window](/sites/default/files/styles/scale_exact_400x400_/public/2024-01/OALV%20design.png?itok=xMV74hXb)
LLNL researchers has developed designs to augment WBG/UWBG-based OALVs to improve their power handling capability under CW operational environments. These designs include:
![Segments of transmission line lengths can be switched to open circuit (as shown) or shorted to the ground (not shown)](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/Segments%20of%20tranmission%20line%20lengths.png?itok=FF0qaBGw)
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)…
![Annular illumination on photo conductor by Conical Total Internal Reflection “CTIR” endcap](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/CONIFR.png?itok=L4wSanXF)
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…
![drift_meter_thumb.jpg drift_meter_thumb](/sites/default/files/styles/scale_exact_400x400_/public/2019-08/drift_meter_thumb.jpg?itok=1NiNsyHm)
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…
![OTV Image](/sites/default/files/styles/scale_exact_400x400_/public/2022-02/OTV%20Image.png?itok=KEAmHqpM)
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…
![Electronic Wave](/sites/default/files/styles/scale_exact_400x400_/public/2022-06/electronic%20wave.jpg?itok=v7aKMJKH)
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…