A5021310378- Photonic Crystal and Fiber Optics
- Advanced Fiber Optic Sensors
- Advanced Fiber Laser Technologies
- Solid State Laser Technologies
- Laser Design and Applications
- Optical Network Technologies
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Optical Sensing Technologies
- Spectroscopy and Laser Applications
- Laser-Matter Interactions and Applications
- Optical Systems and Laser Technology
- Laser Material Processing Techniques
- Force Microscopy Techniques and Applications
- Quantum Information and Cryptography
- Quantum optics and atomic interactions
- Laser and Thermal Forming Techniques
- Photoacoustic and Ultrasonic Imaging
- Optical Coherence Tomography Applications
- Atomic and Subatomic Physics Research
- Advanced Surface Polishing Techniques
- Mechanical and Optical Resonators
- Ocular and Laser Science Research
- Gyrotron and Vacuum Electronics Research
Lawrence Livermore National Laboratory
2012-2022
Friedrich Schiller University Jena
2013
Helmholtz Institute Jena
2013
Fraunhofer Institute for Applied Optics and Precision Engineering
2013
University of Michigan–Ann Arbor
2013
Michigan United
2013
National Ignition Facility
2012
University of Arizona
1992-2003
Continuum Dynamics (United States)
1991
We analyze the scalability of diffraction-limited fiber lasers considering thermal, non-linear, damage and pump coupling limits as well mode field diameter (MFD) restrictions. derive new general relationships based upon practical considerations. Our analysis shows that if fiber's MFD could be increased arbitrarily, 36 kW power obtained with quality from a laser or amplifier. This limit is determined by thermal non-linear combine to prevent further scaling, irrespective increases in size....
We trap neutral Cs atoms in a two-dimensional optical lattice and cool them close to the zero-point of motion by resolved-sideband Raman cooling. Sideband cooling occurs via transitions between vibrational manifolds associated with pair magnetic sublevels required coupling is provided potential itself. obtain mean excitations \bar{n}_x \approx \bar{n}_y 0.01, corresponding population \sim 98% ground state. Atoms state an provide new system which explore quantum control subrecoil laser
A developed formalism<sup>1</sup> for analyzing the power scaling of diffraction limited fiber lasers and amplifiers is applied to a wider range materials. Limits considered include thermal rupture, lensing, melting core, stimulated Raman scattering, Brillouin optical damage, bend induced limits on core diameter coupling pump diode light into fiber. For conventional based upon silica, single aperture, limit was found be 36.6kW. This hard upper that results from an interaction scattering with...
We have constructed a double clad neodymium doped fiber laser operating on the three-level 4F3/2→4I9/2 transition. The has produced 11.5 W at 925 nm with 55% slope efficiency when pumped 808 nm, comparable to best previous results for double-clad configuration this Higher power pumping both and 880 sources resulted in an output of 27 W, albeit lower efficiency. In cases, was limited by available pump, indicating potential further scaling. To suppress stronger four-level 4F3/2→4I11/2...
A Nd3+ fiber amplifier with gain from 1376 nm to 1466 is demonstrated. This enabled by a wavelength selective waveguide that suppresses amplified spontaneous emission between 850 and 1150 nm. It shown while excited state absorption (ESA) precludes net below 1375 the exception of small band 1333 1350 nm, ESA diminishes steadily beyond allowing for construction an efficient peak at 1400 potential 1500 signal 13.3 dB measured 1402 noise figure 7.6 dB. Detailed measurements cross sections...
Experiments with a high-power laser beam directed onto thin aluminum sheets, large spot size, demonstrate that airflow produces strong enhancement of the interaction. The is explained in terms aerodynamic effects. As heating softens material, airflow-induced pressure difference between front and rear faces causes metal to bulge into beam. resulting shear stresses rupture material remove it at temperatures well below melting point. shown conform an elementary model. We present analytic model...
Mode conversion from the fundamental to a higher-order mode in rectangular-core optical fiber is accomplished by applying pressure with edge of flat plate. Modal analysis near and far field images fiber's transmitted beam determines purity converted mode. reaching 75% targeted achieved using this technique. Conversion back also demonstrated comparable efficiency. Propagation allows for better thermal management bend-loss immunity than conventional circular-core fibers, extending...
We compute the near-resonant dipole-dipole interaction between atoms in a three-dimensional optical lattice. After general derivation, we concentrate specifically on case of J=1/2\ensuremath{\rightarrow}J=3/2 off-resonant transition, which excited electronic states can be adiabatically eliminated. present detail spatial dependence resulting effective potential, and discuss physical origin its anisotropy. In addition to impacting center-of-mass motion atoms, potential induce transitions...
Lawrence Livermore National Laboratory (LLNL) has been developing compact solid state lasers since the 1990's. One of first to be developed utilized flashlamp pumped architecture and neodymium glass as laser gain media. In early 2000's, a diode version original was designed built, responding requirements that system for military in both size weight while creating significant power (~100 kW) missions envisioned. This paper will discuss evolution at LLNL provide glimpse into types capabilities...
We propose and demonstrate amplification of a single high-order mode in an optical fiber having elongated, ribbon-like core effective area 600 µm(2) aspect ratio 13:1. When operated as amplifier, the double-clad, ytterbium doped, photonic crystal produced 50% slope efficiency seed-limited power 10.5 W, corresponding to gain 24 dB. The high order remained pure through 20 dB without intervention or realignment.
To analyze recent experiments with a neodymium-doped fiber amplifier operating in the E-band of wavelengths (1350-1450 nm) and embedded fused silica, we develop time-dependent model consisting rate equations for aggregate ion populations radiation intensities along axis. Both copropagating counterpropagating intensities, including amplified spontaneous emission, are incorporated. The wavelength-dependent cross section excited state absorption is inferred from auxiliary measurements....
We present a detailed theoretical investigation of cladding-pumped Raman fiber amplification in an unexplored parameter space high conversion efficiency (> 60%) and brightness enhancement 1000). Fibers with large clad-to-core diameter ratios can provide promising means for Raman-based diode pump sources. Unfortunately, the ratio cannot be extended indefinitely since intensity generated core greatly exceed that cladding long before is fully depleted. If left uncontrolled, this leads to...
A rectangular-core (ribbon) fiber that guides and amplifies a single higher-order-mode (HOM) can potentially scale to much higher average powers than what is possible in traditional circular-core large-mode-area fibers. Such an amplifier would require mode-conversion at the input enable interfacing with seed sources typically output TEM(00) mode radiation generate diffraction-limited for end-user applications. We present first simulation experimental results of conversion technique uses two...
Optical fibers in the ribbon geometry have potential to reach powers well above maximum anticipated power of a circular core fiber. In this paper we report first doped silica high order mode fiber oscillator, with multimode 40 W 71% slope efficiency and single 5 44% efficiency.
Selection of the fundamental mode an active large area "ribbon" fiber laser with core dimensions 107.8 μm by 8.3 was produced a transmitting Bragg grating (TBG) in free-space resonator. The multimode performance original characterized to have M2 11.3 absorbed power slope efficiency 76%. With TBG aligned provide maximum diffraction for mode, improved 1.45 at 54% and enhanced brightness 5.1 times.
The Solid-State, Heat-Capacity Laser (SSHCL) program at Lawrence Livermore National Laboratory is a multi-generation laser development effort scalable to the megawatt power levels with current performance approaching 100 kilowatts. This one of many designed harness lasers for use as directed energy weapons. There are hurdles common all these programs that must be overcome make technology viable. will in-depth discussion general issues facing state-of-the-art high and paths their resolution....
We have demonstrated a photonic crystal fiber-based regenerative amplifier at 1.078 microm. The input signal pulse energy is 20 pJ in 12 ns 3 kHz repetition rate. At 8.6 W of pump power, the amplified output 157 microJ, yielding gain 69 dB. To our knowledge, this highest achieved to date any wavelength.
Lasers are of increasing interest to the accelerator community and include applications as diverse stripping electrons from hydrogen atoms, sources for Compton scattering, efficient high repetition rate lasers dielectric laser acceleration, peta-watt peak power wake field energy, short pulse proton ion beam therapy. The requirements these briefly surveyed. State art technologies with potential eventually meet those reviewed. These diode pumped solid state (including cryogenic), fiber lasers,...
A 9.3dB improvement in optical gain and a 100x total power over prior published experimental results from the 4F3/2 to 4I13/2 transition an Nd3+ doped fused silica fiber is demonstrated. This enabled via waveguide design that creates high spectral attenuation 1050-1120nm-wavelength range, continuous filter for primary 4I11/2 transition. maximum output at 1427nm of 1.2W was attained 43mW coupled seed laser 22.2W pump diode 880nm net 14.5dB. Reducing 2.5mW system attain 19.3dB 16.5W power....
The fundamental power scaling limits for diffraction limited fiber lasers are reviewed. Relationships between the show there is an upper bound single aperture of conventional 10–40kW.
We carry out quantum and semiclassical numerical simulations of the dynamics, particularly diffusion, atoms in an optical lattice. consider specifically situation a $J=1/2\ensuremath{\leftrightarrow}J=3/2$ atomic transition, whose experimental counterpart can be realized ${\mathrm{Mg}}^{+}$ experiments. The results, which cover larger range parameters than would practical for fully calculations, confirm extend work Marksteiner et al. [Phys. Rev. A 53, 3409 (1996)], characterize transition...
A resonator in which the dominant mode-shaping effect is diffraction from an undersized aperture reported. The result a large mode volume and near diffraction-limited Gaussian output beam. alignment sensitivity similar to that of positive branch unstable resonator, although mirror configuration can vary over range either geometrically stable or regimes. pulsed Nd:YAG laser using this was built characterized free-running, Q-switching, mode-locking regimes, as regenerative amplifier.< <ETX...
Distributed fiber optic acoustic sensing is becoming widely used and modeling of the signals an essential tool. Here we examine response to imposed strain assist in calibration models. The estimated numerically using both semi-analytic numerical models then tested laboratory field. Presentation Date: Thursday, October 18, 2018 Start Time: 8:30:00 AM Location: 212A (Anaheim Convention Center) Type: Oral