A5029943884- Advanced Surface Polishing Techniques
- Laser Material Processing Techniques
- Laser-induced spectroscopy and plasma
- Advanced machining processes and optimization
- Laser-Plasma Interactions and Diagnostics
- Diamond and Carbon-based Materials Research
- Glass properties and applications
- Solid State Laser Technologies
- Laser Design and Applications
- Surface Roughness and Optical Measurements
- Ocular and Laser Science Research
- Luminescence Properties of Advanced Materials
- Optical Coatings and Gratings
- Advanced Optical Sensing Technologies
- Nanofabrication and Lithography Techniques
- Advanced ceramic materials synthesis
- Analytical Chemistry and Sensors
- Aerogels and thermal insulation
- Advanced Measurement and Metrology Techniques
- Photochemistry and Electron Transfer Studies
- Nuclear Physics and Applications
- Photonic and Optical Devices
- High-pressure geophysics and materials
- Additive Manufacturing and 3D Printing Technologies
- Photonic Crystals and Applications
Lawrence Livermore National Laboratory
2015-2024
Birmingham City University
2024
Lawrence Livermore National Security
2005-2015
General Atomics (United States)
2014
CEA DAM Île-de-France
2014
Massachusetts Institute of Technology
2014
Fusion Academy
2014
Fusion (United States)
2014
Los Alamos National Laboratory
2014
Rutherford Appleton Laboratory
2014
The possibility of imploding small capsules to produce mini-fusion explosions was explored soon after the first thermonuclear in early 1950s. Various technologies have been pursued achieve focused power and energy required for laboratory-scale fusion. Each technology has its own challenges. For example, electron ion beams can deliver large amounts but must contend with Coulomb repulsion forces that make focusing these a daunting challenge. demonstration laser 1960 provided new option. Energy...
Silica inks are developed, which may be 3D printed and thermally processed to produce optically transparent glass structures with sub-millimeter features in forms ranging from scaffolds monoliths. The composed of silica powder suspended a liquid using direct ink writing. then dried sintered at temperatures well below the melting point form amorphous, solid, structures. This technique enables mold-free formation previously inaccessible conventional fabrication processes.
The National Ignition Facility (NIF) laser with its 192 independent beams is not only the world's largest but also optical system ever built. With beams, NIF requires a total of 7648 large-aperture (meter-sized) optics. One many challenges in designing and building has been to carry out research development on materials, optics design, manufacturing metrology technologies needed achieve NIF's high output energies precision beam quality. This paper describes multiyear, multisupplier effort...
In this work we present the design of first controlled fusion laboratory experiment to reach target gain G>1 N221204 (5 December 2022) [Phys. Rev. Lett. 132, 065102 (2024)], performed at National Ignition Facility, where energy produced (3.15 MJ) exceeded amount laser required drive (2.05 MJ). Following demonstration ignition according Lawson criterion N210808, experiments were impacted by nonideal experimental fielding conditions, such as increased (known) defects that seeded hydrodynamic...
An indirect-drive inertial fusion experiment on the National Ignition Facility was driven using 2.05 MJ of laser light at a wavelength 351 nm and produced 3.1±0.16 total yield, producing target gain G=1.5±0.1 exceeding unity for first time in laboratory [Phys. Rev. E 109, 025204 (2024)10.1103/PhysRevE.109.025204]. Herein we describe experimental evidence increased drive capsule additional energy control over known degradation mechanisms, which are critical to achieving high performance....
The effect of various HF‐based etching processes on the laser damage resistance scratched fused silica surfaces has been investigated. Conventionally polished and subsequently plates were treated by submerging in etchants (HF or NH 4 F:HF at ratios concentrations) under different process conditions (e.g., agitation frequencies, etch times, rinse conditions, environmental cleanliness). Subsequently, (at 351 355 nm) surface was measured. found to be strongly dependent scaled inversely with...
The use of any optical material is limited at high fluences by laser-induced damage to surfaces. In many materials, the results from a series sources which initiate large range and intensities. Much progress has been made recently eliminating silica surface due fracture-related precursors relatively low (i.e., less than 10 J/cm(2), when damaged 355 nm, 5 ns pulses). At higher fluence, most materials are other classes exhibit strong threshold behavior areal density (>10(5) cm(-2)); we refer...
The optical damage threshold of indentation-induced flaws on fused silica surfaces was explored. Mechanical were characterized by laser testing, as well optical, secondary electron, and photoluminescence microscopy. Localized polishing, chemical leaching, the control indentation morphology used to isolate structural features that limit damage. A thin defect layer fracture surfaces, including those smaller than wavelength visible light, found be dominant source initiation during illumination...
After every other failure mode has been considered, in the end, high-performance limit of all lasers is set by optical damage. The demands inertial confinement fusion (ICF) pushed designed as ICF drivers into this from their very earliest days. first were small, and pulses short. Their goal was to provide much power target possible. Typically, they faced damage due high intensity on optics. As requests for higher laser energy, longer pulse lengths, better symmetry appeared, new kinds also...
The National Ignition Facility (NIF) at Lawrence Livermore Laboratory (LLNL) houses the world's largest laser system, composed of 192 individual, 40-cm-aperture beamlines. NIF routinely operates ultraviolet (UV) fluences above 8 J/cm2, more than twice (3ω only) damage threshold commercially available UV-grade fused silica. is able to maintain such high fluence operation by using an optics recycling loop strategy. Successful relies on a number technologies specifically developed for NIF. One...
Abstract A method for fabricating optical quality silica and silica–titania glasses by three‐dimensional (3D) printing is reported. Key to this success the combination of sol–gel derived colloidal feedstocks, direct ink writing (DIW) technology, conventional glass thermal processing methods. Printable sol inks are prepared directly from molecular precursors a simple one‐pot method, which optimized yield viscous, shear‐thinning suspensions with tuned rheology ideal DIW. After printing, parts...
Managing subsurface damage during the shaping process and removing polishing is essential in production of low density optical components, such as those required for use on high peak power lasers. Removal damage, process, requires to a depth which greater than residual cracks present following process. To successfully manage, ultimately remove understanding distribution character fractures region introduced fabrication important. We have characterized morphology fixed abrasive loose grinding...
Using high-sensitivity confocal time-resolved photoluminescence (PL) techniques, we report an ultrafast PL (40 ps–5 ns) from impurity-free surface flaws on fused silica, including polished, indented, or fractured surfaces of and laser-heated evaporation pits. This is excited by the single-photon absorption sub-band gap light, especially bright in fractures. Regions which exhibit this are strongly absorptive well below band gap, as evidenced a propensity to damage with 3.5 eV nanosecond-scale...
High energy laser systems are ultimately limited by laser-induced damage to their critical components. This is especially true of fused silica optics, which grows rapidly upon exposure additional pulses. Much progress has been made in eliminating precursors as-processed optics (the advanced mitigation process, AMP3), and very high resistance demonstrated laboratory studies. However, the full potential these improvements not yet realized actual systems. In this work, we explore importance...
The chemical characteristics and the proposed formation mechanisms of modified surface layer (called Beilby layer) on polished fused silica glasses are described. Fused glass samples were using different slurries, polyurethane pads, at rotation rates. concentration profiles several key contaminants, such as Ce, K, H, measured in near Secondary Ion Mass Spectroscopy ( SIMS ). penetration originating from KOH used for pH control during polishing, decreased with increase polishing material...
Direct ink writing (DIW) three-dimensional (3D) printing provides a revolutionary approach to fabricating components with gradients in material properties. Herein, we report method for generating colloidal germania feedstock and germania–silica inks the production of optical quality (GeO2–SiO2) glasses by DIW, making available new composition development multimaterial functionally graded ceramics additive manufacturing. Colloidal silica particles are prepared base-catalyzed sol–gel converted...
Several silylated coumarin dyes with different linkages and degrees of functionality have been synthesized incorporated in both SiO2 xerogels various solvent hosts. The absorption fluorescence spectra were examined to explore selected structural environmental effects on the optical properties these dyes. Silylated (also referred as grafted or functionalized dyes) are dye molecules that chemically altered provide alkoxysilane allowing active molecule be covalently bonded host. Silylation had...