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  1. Roadmap on basic research needs for laser technology

    Motivated by the profound impact of laser technology on science, arising from an increase in focused light intensity by seven orders of magnitude and flashes so short electron motion is visible, this roadmap outlines the paths forward in laser technology to enable the next generation of science and applications. Despite remarkable progress, the field confronts challenges in developing compact, high-power sources, enhancing scalability and efficiency, and ensuring safety standards. Future research endeavors aim to revolutionize laser power, energy, repetition rate and precision control; to transform mid-infrared sources; to revolutionize approaches to field control and frequency conversion. These require reinvention ofmore » materials and optics to enable intense laser science and interdisciplinary collaboration. The roadmap underscores the dynamic nature of laser technology and its potential to address global challenges, propelling progress and fostering sustainable development. Ultimately, advancements in laser technology hold promise to revolutionize myriad applications, heralding a future defined by innovation, efficiency, and sustainability.« less
  2. Integrated structured light architectures

    Abstract The structural versatility of light underpins an outstanding collection of optical phenomena where both geometrical and topological states of light can dictate how matter will respond or display. Light possesses multiple degrees of freedom such as amplitude, and linear, spin angular, and orbital angular momenta, but the ability to adaptively engineer the spatio-temporal distribution of all these characteristics is primarily curtailed by technologies used to impose any desired structure to light. We demonstrate a laser architecture based on coherent beam combination offering integrated spatio-temporal field control and programmability, thereby presenting unique opportunities for generating light by design to exploitmore » its topology.« less
  3. Controllable X-Ray Pulse Trains from Enhanced Self-Amplified Spontaneous Emission

    Here, we report the demonstration of optical compression of an electron beam and the production of controllable trains of femtosecond, soft X-ray pulses with the Linac Coherent Light Source (LCLS) free-electron laser (FEL). This is achieved by enhanced self-amplified spontaneous emission (ESASE) with a 2~ μ m laser and a dechirper device. Optical compression was achieved by modulating the energy of an electron beam with the laser and then compressing with a chicane, resulting in high current spikes on the beam which we observe to lase. A dechirper was then used to selectively control the lasing region of the electronmore » beam. Field autocorrelation measurements indicate a train of pulses, and we find that the number of pulses within the train can be controlled (from 1 to 5 pulses) by varying the dechirper position and undulator taper. These results are a step towards attosecond spectroscopy with X-ray FELs as well as future FEL schemes relying on optical compression of an electron beam.« less
  4. 100  W high-repetition-rate near-infrared optical parametric chirped pulse amplifier

  5. Pulse contrast enhancement via non-collinear sum-frequency generation with the signal and idler of an optical parametric amplifier

    We outline an approach for improving the temporal contrast of a high-intensity laser system by >8 orders of magnitude using non-collinear sum-frequency generation with the signal and idler of an optical parametric amplifier. We demonstrate the effectiveness of this technique by cleaning pulses from a millijoule-level chirped-pulse amplification system to provide >1012 intensity contrast relative to all pre-pulses and amplified spontaneous emission >5 ps prior to the main pulse. The output maintains percent-level energy stability on the time scales of a typical user experiment at our facility, highlighting the method's reliability and operational efficiency. After temporal cleansing, the pulses aremore » stretched in time before seeding two multi-pass, Ti:sapphire-based amplifiers. After re-compression, the 1 J, 40 fs (25 TW) laser pulses maintain a >10^10 intensity contrast >30 ps prior to the main pulse. This technique is both energy-scalable and appropriate for preparing seed pulses for a TW- or PW-level chirped-pulse amplification laser system.« less
  6. High average power 88 W OPCPA system for high-repetition-rate experiments at the LCLS x-ray free-electron laser

    Here, we present a 100 kHz, sub-20 fs optical parametric chirped-pulse amplifier (OPCPA) system delivering 88.6 W average power at a center wavelength of 800 nm. The seed pulses are derived from the pump laser via white-light continuum generation and are amplified in three non-collinear OPCPA stages. The final two high-power stages are pumped with a 661 W Yb:YAG InnoSlab amplifier. A simple and robust design is used for the OPCPA system to avoid thermal effects and enhance long-term stability, resulting in excellent beam quality and high conversion efficiency. To the best of our knowledge, this is the highest averagemore » power OPCPA system reported to date.« less
  7. Shock drive capabilities of a 30-Joule laser at the matter in extreme conditions hutch of the Linac Coherent Light Source

    In this paper, we measure the shock drive capabilities of a 30 J, nanosecond, 527 nm laser system at the matter in extreme conditions hutch of the Linac Coherent Light Source. Using a velocity interferometer system for any reflector, we ascertain the maximum instantaneous ablation pressure and characterize its dependence on a drive laser spot size, spatial profile, and temporal profile. We also examine the effects of these parameters on shock spatial and temporal uniformity. Our analysis shows the drive laser capable of generating instantaneous ablation pressures exceeding 160 GPa while maintaining a 1D shock profile. We find that slopemore » pulses provide higher instantaneous ablation pressures than plateau pulses. Our results show instantaneous ablation pressures comparable to those measured at the Omega Laser Facility in Rochester, NY under similar optical drive parameters. In conclusion, we analyze how optical laser ablation pressures are compare with known scaling relations, accounting for variable laser wavelengths.« less
  8. Light-induced picosecond rotational disordering of the inorganic sublattice in hybrid perovskites

    Femtosecond resolution electron scattering techniques are applied to resolve the first atomic-scale steps following absorption of a photon in the prototypical hybrid perovskite methylammonium lead iodide. Following above-gap photoexcitation, we directly resolve the transfer of energy from hot carriers to the lattice by recording changes in the mean square atomic displacements on 10-ps time scales. Measurements of the time-dependent pair distribution function show an unexpected broadening of the iodine-iodine correlation function while preserving the Pb-I distance. This indicates the formation of a rotationally disordered halide octahedral structure developing on picosecond time scales. Here, this work shows the important role ofmore » light-induced structural deformations within the inorganic sublattice in elucidating the unique optoelectronic functionality exhibited by hybrid perovskites and provides new understanding of hot carrier-lattice interactions, which fundamentally determine solar cell efficiencies.« less
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"Fry, Alan"

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