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…
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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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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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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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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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LLNL researchers have developed a high average power Faraday rotator that is gas-cooled and uniquely designed to dissipate heat uniformly so that it does not build up in the optical component and affect its performance. The Faraday rotator material is sliced into smaller disks like a loaf of bread so that high speed helium gas can flow between the slices. With this highly efficient cooling…
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This invention discloses a method to minimize transient variations in the wavelength- and/or pointing-behavior of an optic, without requiring a reduction in its thermal resistance, optical absorption, or operating irradiance. The invention employs a combination of a time-varying heat source and time-varying thermal resistance and/or heat sink temperature to achieve temperature stability of the…
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This invention concerns a new type of optic: a transient gas or plasma volume grating produced indirectly by small secondary lasers or directly by nonlinear processes using the primary beams themselves. When used in conjunction with advantageously placed shielding it offers a means of protecting the final optical components of a high-repetition-rate IFE facility. These transmission optics are…
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Livermore Lab researchers have developed two new methods for improving the efficiency of laser drilling. The first method is based on multi-pulse laser technology. Two synchronized free-running laser pulses from a tandem-head Nd:YAG laser and a gated CW laser are capable of drilling through 1/8-in-thick stainless-steel targets at a standoff distance of 1 m without gas-assist. The combination of a…
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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.
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LLNL’s system consists of one or more flashlamp-pumped Nd:glass zig-zag amplifiers, a very low threshold stimulated-Brillouin-scattering (SBS) phase conjugator system, and a free-running single frequency Nd:YLF master oscillator.