A5071062937- Advanced Fiber Laser Technologies
- Photonic Crystal and Fiber Optics
- Laser-Matter Interactions and Applications
- Laser-Plasma Interactions and Diagnostics
- Photonic and Optical Devices
- Plasmonic and Surface Plasmon Research
- Advanced optical system design
- Nanofabrication and Lithography Techniques
- Photocathodes and Microchannel Plates
- Advanced Fiber Optic Sensors
- Spectroscopy and Laser Applications
- Advanced Electron Microscopy Techniques and Applications
- Solid State Laser Technologies
- Terahertz technology and applications
- Electron and X-Ray Spectroscopy Techniques
- Laser-induced spectroscopy and plasma
- Particle Accelerators and Free-Electron Lasers
- Advancements in Photolithography Techniques
- Gyrotron and Vacuum Electronics Research
- Random lasers and scattering media
- Particle Detector Development and Performance
- Bacterial Identification and Susceptibility Testing
- Optical Network Technologies
- Laser Design and Applications
- Optical Coatings and Gratings
University of California, Los Angeles
2018-2020
Tsinghua University
2014-2017
SLAC National Accelerator Laboratory
2015
University of California, Berkeley
2004-2012
Abstract Advances in ultrafast laser technology and nanofabrication have enabled a new class of particle accelerator based upon miniaturized laser-driven photonic structures. However, developing useful on this approach requires control the dynamics at field intensities approaching damage limit. We measure acceleration fused silica dielectric driven by fields up to 9 GV m −1 observe record 1.8 accelerating mode. At these is beyond its linear response self-phase modulation changes phase...
Using an 800 nm, 45 fs pulse-front-tilted laser we demonstrate a record 315 keV energy gain in dual grating dielectric accelerator (DLA) and average accelerating gradients of 560 MV/m over 0.5 mm. These results open new regime DLA characterized by significant evolution the beam distribution longitudinal phase space, corresponding to >1/4 synchrotron oscillation. By tilting wavefront control resonant velocity observe net gain, indicating that tapered optical could be used achieve very high gain.
Generation of nanosecond pulses with 55-mJ energy and 4.8-MW peak power are demonstrated in a multistage fiber amplifier system, which is seeded 10-nm broadband from superluminescence diode. The at low repetition 10 Hz width ns. High high for obtained simultaneously amplifier. In particular, the least two times previous pulses.
A microplastic lens array has been successfully constructed on top of a 500-/spl mu/m-thick PC (Polycarbonate film) by using micro hot intrusion process. single-layer LIGA process is used to fabricate the high-aspect-ratio nickel mold insert that circular hole patterns 80 /spl mu/m in diameter and 200 depth. Under process, plastic material can be intruded into these circular-shape holes stopped at desired depth under elevated temperature pressure microlenses. By adjusting embossing load,...
Nanosecond (~10 ns) laser pulses with high peak power of 8 MW and energy 100 mJ are reported, which generated by a cascaded pulsed Yb-doped fiber amplifier system working at repetition frequency 10 Hz. The that is higher than the self-focusing threshold for Gaussian beams achieved first time in lasers. To analyze multimode lasers fibers, novel mode decomposition based on beam quality measurements introduced. Based nonlinear propagation simulations, our case estimated.
We report a continuous-wave, broadly tunable mid-infrared MgO:PPLN optical parametric oscillator pumped by fiber amplifier. Using pump tuning with synchronized temperature optimization, we achieve the broadest mode-hop-free (MHF) of idler light over 30 cm(-1). further use this laser to demonstrate high-resolution absorption spectroscopy methane across MHF range.
We present a methodology for designing and measuring pulse front tilt in an ultrafast laser use dielectric acceleration. Previous research into accelerating modules has focused on high gradients novel structures, but done so only short electron-laser coupling lengths. Here we demonstrate optical design to extend the laser-electron interaction 1mm.
Stimulated Raman scattering (SRS) is an important limiting factor for achieving high peak power intensity in fiber amplifier systems. It was proposed to use partially coherent light increase the SRS threshold significantly. In this paper, of silica fibers investigated by both experiments and theoretical analysis, which show that independent on coherency when bandwidth much narrower than 30 nm.
SPM is an important limitation in some fiber lasers and amplifier systems. In this paper, the influence of gain saturation on SPM-induced spectral broadening for coherent incoherent nanosecond pulses discussed. The models are generalized to amplification with saturation. Experiments conducted validate our theoretical analysis a super-luminescent diode seeded cascaded system where high peak power pulse energy generated occurs. Excellent agreements between experimental results obtained, higher...
The use of sub-wavelength metal structures to locally enhance high frequency electromagnetic fields, generally known as plasmonics, enables breakthrough opportunities across diverse fields research such nonlinear optics, biosensing, photovoltaics and others. Here we study the application metallic resonators tuned in THz range for manipulation diagnostics relativistic electron beams. In this work, report on a double-sided split-ring structure driven by near single cycle field generated...
Dielectric Laser Acceleration (DLA) achieves the highest gradients among structure-based electron accelerators. The use of dielectrics increases breakdown field limit, and thus achievable gradient, by a factor at least 10 in comparison to metals. Experimental demonstrations DLA 2013 led Accelerator on Chip International Program (ACHIP), funded Gordon Betty Moore Foundation. In ACHIP, our main goal is build an accelerator silicon chip, which can accelerate electrons from below 100 keV above 1...
A phenomenological model for spectral broadening of incoherent light in silica fibers via self-phase modulation and dispersion is presented, aiming at providing a qualitative readily accessible description broadening.In this model, the approximated by cosine power-modulated with parameters depending on coherent time fibers.A simple practical method predictions given, demonstrated both straightforward NLSE-based numerical modeling series experiments including narrowband broadband passive...
We demonstrated nanosecond (~10 ns) broadband nm) pulses with the highest energy (over 100 mJ) and peak power 8 MW) to our knowledge, utilizing a multi-stage fiber amplifier system.
High coherence of the laser is indispensable light sources in modern long or short-distance imaging systems, because high leads to coherent artifacts such as speckle that corrupt image formation. To deliver low pulses fiber amplifiers, we utilize superluminescent pulsed with broad bandwidth, nonlongitudinal mode structure and chaotic phase seed source cascaded amplifiers. The influence pulse amplification (SPA) on limitations performance analyzed. A review our research results for SPA fibers...
Journal Article Development of MeV Ultrafast Electron Scattering Instruments at SLAC National Accelerator Laboratory Get access R K Li, Li Laboratory, 2575 Sand Hill Rd, Menlo Park, California 94025 USA Search for other works by this author on: Oxford Academic Google Scholar A H Reid, Reid S P Weathersby, Weathersby G Brown, Brown M Centurion, Centurion University Nebraska-Lincoln, 855 N 16th Street, Lincoln, Nebraska 68588, T Chase, Chase Coffee, Coffee J Corbett, Corbett C Frisch, Frisch...
We reported a high average power of 570 W laser generated by an all-fiber superluminescent pulse amplifier (SPA) structure, operating at variable repetition rates from 0.5 MHz to 2 and widths 100 ns 220 ns.
Nanoscale electron pulses are increasingly in demand, including as probes of nanoscale ultrafast dynamics and for emerging light source lithography applications. Using electromagnetic simulations, we show that gold plasmonic lenses multiphoton photoemitters provide unique advantages, emission from an atomically at surface, pulse diameter regardless laser spot size, femtosecond-scale response time. We then present fabrication prototypes with sub-nm roughness via e-beam lithography, well...