Engineering topics

Fasano, N. M.

Publications and source records attributed to Fasano, N. M..

7 records

DOE OSTI2024

Greater than Five-Order-of-Magnitude Postcompression Temporal Contrast Improvement with an Ionization Plasma Grating

High-intensity lasers require suppression of prepulses and other nonideal temporal structure to avoid target disruption before the arrival of the main pulse. Here, to address this, we demonstrate that ionization gratings act as a controllable optical switch for high-power light with a temporal contrast improvement of at least 3 ×10 5 and a switching time less than 500 fs. We also show that a grating system can run for hours at 10 Hz without degradation. The contrast improvement from an ionization grating compares favorably to that achievable with plasma mirrors.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2022

Holographic Plasma Lenses

We report a hologram fully encodes a three-dimensional light field by imprinting the interference between the field and a reference beam in a recording medium. Here we show that two collinear pump lasers with different foci overlapped in a gas jet produce a holographic plasma lens capable of focusing or collimating a probe laser at intensities several orders-of-magnitude higher than the limits of a nonionized optic. We outline the theory of these diffractive plasma lenses and present simulations for two plasma mechanisms that allow their construction: spatially varying ionization and ponderomotively driven ion-density fluctuations. Damage-resistant plasma optics are necessary for manipulating high-intensity light, and divergence control of high-intensity pulses—provided by holographic plasma lenses—will be a critical component of high-power plasma-based lasers.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2021

High-Power Ultraviolet Vortex Beams Generated from a Relativistic Laser Interacting with an Ultrathin Foil

Ultrathin foils irradiated by relativistic circularly polarized lasers emit harmonics in both the transmitted and reflected directions that contain orbital angular momentum. Here, we demonstrate this scheme using ab-initio three-dimensional particle-in-cell simulations.

Fasano, N. M.↗

DOE OSTI2021

Measuring the Optical Properties of Ionization Gratings in Air for Control of Femtosecond Lasers

Interference between crossed femtosecond lasers can drive spatially varying ionization, producing a high-flux plasma optic. Here, we measure the plasma and optical properties of an ionization grating in air as it redirects a millijoule-scale probe beam.

Edwards, M. R.↗

DOE OSTI2020

A multi-terawatt two-color beam for high-power field-controlled nonlinear optics

Two-color laser beams are instrumental in light-field control and enhancement of high-order harmonic, spectral supercontinuum, and terahertz radiation generated in gases, plasmas, and solids. Here we demonstrate a multi-terawatt two-color beam produced using a relativistic plasma mirror, with 110 mJ at 800 nm and 30 mJ at 400 nm. Both color components have high spatial quality and can be simultaneously focused, provided that the plasma mirror lies within a Rayleigh range of the driving fundamental beam. Favorable scaling of second-harmonic generation by plasma mirrors at relativistic intensities suggests them as an excellent tool for multi-color waveform synthesis beyond the petawatt level.

42 ENGINEERING↗

DOE OSTI2020

Effects of Electron Bunch Width on the Efficiency of High-Order Harmonic Generation from Ultrathin Solid Targets

Here, we demonstrate the importance of the finite extent of the electron bunch width on the spectral power law and the efficiency of high harmonic generation from a relativistic laser interacting with an ultrathin target.

Fasano, N. M.↗

DOE OSTI2020

Cascaded Plasma Mirrors for Enhanced Relativistic Harmonic Generation

Relativistic harmonic generation is a waveform-dependent process that can be enhanced by multi-color driving pulses. We experimentally demonstrate higher-efficiency harmonics from a plasma mirror cascade, where an initial plasma mirror produces the multi-color beam.

Edwards, M. R.↗