A5012916454- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Laser-induced spectroscopy and plasma
- Laser-Plasma Interactions and Diagnostics
- Laser Material Processing Techniques
- Photonic Crystal and Fiber Optics
- Solid State Laser Technologies
- Laser Design and Applications
- Atomic and Molecular Physics
- Advanced X-ray Imaging Techniques
- Particle Accelerators and Free-Electron Lasers
- Diamond and Carbon-based Materials Research
- Electron and X-Ray Spectroscopy Techniques
- Advanced Optical Sensing Technologies
- Nonlinear Optical Materials Studies
- Plasma Diagnostics and Applications
- Photonic Crystals and Applications
- Gyrotron and Vacuum Electronics Research
- Spectroscopy and Quantum Chemical Studies
- High-pressure geophysics and materials
- Nonlinear Optical Materials Research
- Optical Systems and Laser Technology
- Advanced Fluorescence Microscopy Techniques
- Advancements in Photolithography Techniques
- Optical Coherence Tomography Applications
DEVCOM Army Research Laboratory
2013-2023
United States Army Combat Capabilities Development Command
2022-2023
Los Alamos National Laboratory
2006-2008
University of Michigan–Ann Arbor
2000-2006
Optical Sciences (United States)
2002-2003
Universidad Nacional de Cuyo
1971
Bariloche Atomic Centre
1971
Comisión Nacional de Energía Atómica
1971
The distant projection of high-peak and average-power laser beams in the atmosphere is a long-standing goal with wide range applications. Our early proof-of-principle experiments [Phys. Rev. X 4, 011027 (2014)] presented one solution to this problem, employing energy deposition femtosecond filaments air sculpt millisecond-lifetime sub-meter-length waveguides. Here, we demonstrate waveguiding at 50-m scale, 60×longer, making many practical applications now possible. We employ new method for...
Polycrystalline ZnSe is an exciting source of broadband supercontinuum and high-harmonic generation via random quasi phase matching, exhibiting broad transparency in the mid-infrared (0.5-20 μm). In this work, effects wavelength, pulse power, intensity, propagation length, crystallinity on high harmonic are investigated experimentally using ultrafast pulses. Observed conversion efficiency scales linearly reaching as 36%. For first time to our knowledge, n2 measured for wavelengths ZnSe:...
High harmonics generated due to the scattering of relativistic electrons from high intensity laser light is studied. The experiments are carried out with an Nd:Glass system a peak 2×1018 W cm−2 in underdense plasma. It shown that, at intensities, when normalized electric field approaches unity, addition conventional atomic bound there significant contribution harmonic spectrum free electrons. characteristic signatures this found be emission even order harmonics, linear dependence on electron...
In-line spatial holographic methods are used to image the optical diffraction patterns of ultrafast laser produced plasma filaments in air. Using femtosecond pump-probe filament is and subsequently probed by a time-delayed probe beam traversing at right angle. The resulting recorded as pattern on charge coupled device camera diffracted due index change caused filament. Extraction electron density down 1016 cm−3 obtained using Helmholtz wave equation propagation model simulate data. By...
Metal foils are prepared by the technique of evaporation and deposition on a plastic backing, which is subsequently dissolved in acetone. Destruction upon traversing air-liquid interface avoided letting them traverse first layer ether does not dissolve plastic. During whole procedure fabrication never removed from frame originally mounted. Foils have been following metals: copper, gold, nickel, silver tin. Thicknesses as low 8 μg/cm2 (76 Å Ag) obtained.
A high-power fiber laser collimator and array of collimators are described with optical architecture, allowing one to transmit almost 100% the full power output from facets. In case coherent beam combining, more than 70% can be focused into a diffraction limited spot determined by diameter conformal aperture. The truncated-Gaussian tails not trapped inside but redirected through lenses dispersed outside along main collimated beam, thus eliminating requirement for cooling array. Detailed...
Obtaining velocity information from the interaction of a laser pulse on metal layer provides insight into rapid dynamics material removal and plasma plume physics during ablation. A traditional approach involves using interferometer system for any reflector (VISAR) reflective surface. However, when target is thin layer, cohesion surface quickly lost resulting in large spread particle velocities that cannot be easily resolved by VISAR. This due to ejection“confusing” VISAR measurement...
The interaction of a laser-produced electron beam with an ultraintense laser pulse in free space is studied. We show that the optical a(0)=0.5 imparts momentum to beam, causing it deflect along propagation direction. observed 3-degree angular deflection found be independent polarization and good agreement theoretical model for electrons tightly focused Gaussian pulse, but only when longitudinal fields are taken into account. This technique used temporally characterize subpicosecond...
In a single shot, we measure the full propagation path, including evolution to pulse collapse, of high power femtosecond laser propagating in air. This technique enables single-shot examination effect parameters that fluctuate on shot-to-shot basis, such as energy, duration, and air turbulence-induced refractive index perturbations. We find even lab over relatively short distances, turbulence plays significant role determining location collapse.
Results are presented on the generation of high harmonics through scattering relativistic electrons from high-intensity laser light. The characteristic signatures this process found to be emission even-order harmonics, linear dependence electron density, significant amount with circular polarization, and small spatial extent source. emitted as a forward-directed beam divergence 2°–3°. measured profile is in excellent agreement calculations that assume play part process.
Polycrystalline materials can mediate efficient frequency up-conversion for mid-infrared light. Motivated by the need to understand properties of harmonic and supercontinuum radiation from such media, we utilize realistic numerical simulations reveal its complex temporal spatial structure. We show that generated propagates in form long-duration pulse trains be difficult compress optical filamentation high-energy pulses gives rise fine-structured beam profiles. identify trends concerning...
Femtosecond filaments deposit energy into air, leading to localized density depressions. We employ this effect with a multi-filamenting LG 01 beam generate long-lived air waveguides that guide high average power beams up ~50m.
We report on the development of novel high-speed techniques to measure surface topography and instantaneous velocity ablatively launched thin metal layers with sub-nanosecond temporal resolution. Applications for laser detonator technology require understanding fiber optical energy deposition ablative launch a layer into an explosive. Characterization ablation process requires time-resolved diagnosis ejected material state (topography, velocity, density, pressure, etc.). A pulsed Nd:YAG...
We investigate the nonlinear optical properties of ZnSe and ZnS using ultrashort (pulse duration approximately 200 fs) midwave infrared laser pulses between 3 4 μm. Multiple harmonic generation in both materials was observed, as well significant spectral modification fundamental pulse. Simulations a polarization model enhanced with ionization compared favorably experimental data. Random quasi phase matching is likely generator observed harmonics.
Results are presented on the generation of high harmonics due to scattering relativistic electrons from high-intensity laser light. The experiments carried out with a Nd:glass system peak intensity 1019 W cm-2 in underdense He, N2 and Ar plasma. It is shown that, at intensities when normalized electric field approaches unity, addition conventional atomic bound electrons, there significant contribution harmonic spectrum free electrons. characteristic signatures this found be emission...
The Shack-Hartmann Electron Densitometer (SHED) is a novel method to diagnose ultrashort pulse laser–produced plasmas by measuring the phase change probe laser beam. Using method, phasefront of measured through lenslet array onto camera. Small changes in location individual focal points on camera plane are translated into beam's wavefront. These wavefront distortions arise from refractive index variations caused free electrons. This allows for superior performance minute electron density 2...
We describe an optical system for detecting the movement of a surface with subnanosecond temporal and nanometer vertical displacement resolution. The is fielded on experiment to determine distortion laser-ablated metal layer compare results hydrodynamic simulations. also discuss errors that can arise potential means mitigate them. resultant data show one examine dynamic changes reflective accuracy down tens nanometers at hundreds picoseconds time
Strong-field MIR laser-solid interactions have recently generated great interest. Harmonic continuum was in ZnSe with pulses. Power scaling of the harmonics non-perturbative conversion efficiency as high 26%.
Nonlinear refraction coefficients are measured via the Z-scan technique in mid-infrared spectral region for infrared transmitting materials. Harmonic and supercontinuum generation modeled using experimentally obtained values compared to experimental observations.