A5006436071- High-pressure geophysics and materials
- Laser-Plasma Interactions and Diagnostics
- Photonic and Optical Devices
- Laser-induced spectroscopy and plasma
- Semiconductor Lasers and Optical Devices
- Laser-Matter Interactions and Applications
- Semiconductor Quantum Structures and Devices
- Optical Network Technologies
- Laser Design and Applications
- Atomic and Molecular Physics
- Advanced Fiber Laser Technologies
- American Constitutional Law and Politics
- Advanced Photonic Communication Systems
- Plasma Diagnostics and Applications
- Advanced Chemical Physics Studies
- Quantum, superfluid, helium dynamics
- Laser Applications in Dentistry and Medicine
- Combustion and Detonation Processes
- Vacuum and Plasma Arcs
- Diamond and Carbon-based Materials Research
- Cold Atom Physics and Bose-Einstein Condensates
- Cold Fusion and Nuclear Reactions
- Electoral Systems and Political Participation
- Chemical Thermodynamics and Molecular Structure
- Mechanical and Optical Resonators
University of California, Davis
1994-2025
Intel (United States)
2019-2024
Mission College
2019-2023
University of Wisconsin–Madison
2022
Infinera (United States)
2014
University of Würzburg
2002-2004
Lawrence Livermore National Laboratory
1991-2001
University of South Carolina
2001
University of British Columbia
1998
Catholic University of America
1991
A high-intensity laser was used to shock-compress liquid deuterium pressures from 22 340 gigapascals. In this regime is predicted transform an insulating molecular fluid atomic metallic fluid. Shock densities and pressures, determined by radiography, revealed increase in compressibility near 100 gigapascals indicative of such a transition. Velocity interferometry measurements, obtained reflecting probe directly off the shock front flight, demonstrated that shocked above 55 has electrical...
Simultaneous measurements of shock velocity and optical reflectance at 1064, 808, 404 nm a high pressure front propagating through liquid deuterium show continuous increase in from below 10% saturating approximately (40-60)% the range velocities 12 to 20 &mgr;m/ns (pressure 17-50 GPa). The is evidence that shocked reaches conducting state characteristic metallic fluid. Above (50 GPa pressure) constant indicating transformation substantially complete.
Self-assembled InAs quantum-dash (QD) lasers with emission wavelengths between 1.54 and 1.78 μm based on the AlGaInAs-AlInAs-InP material system were grown by gas source molecular beam epitaxy. Threshold current densities below 1 kA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> achieved for 1-mm-long mirror coated broad area a stack of four QD layers. The devices can be operated up to 80/spl deg/C in pulsed mode show high T <sub...
We describe a velocity interferometer used to measure the and trajectory of laser driven shocks in liquid deuterium accurately continuously. This demonstration interferometry shock condensed matter shows strong potential for future studies laser-driven transparent media. Accuracy this technique can be better than 1% ±0.2 μm position during 10 ns interval.
In this paper, we investigate the effect of laser energy on laser-induced breakdown emission intensity and average temperature in a short-pulse plasma generated by using 140 fs excitation. Both line continuum background decrease very rapidly after excitation compared to more conventional nanosecond pulse increase with increasing energy. However, appears be mostly related amount material ablated. Also, nongated spectroscopy (LIBS) is demonstrated high-pulse (1 kHz) repetition rate.
Silicon-photonics based high volume manufacturable lasers are playing an increasingly important role in optical communication and sensing due to their low-cost, performance, seamless integration with other silicon photonics components. Here we demonstrate a silicon-photonics widely tunable laser integrated semiconductor amplifier (SOA) wavelength reference on high-volume, 300-mm III-V/Si platform. The shows tuning range > 50 nm side-mode suppression ratio 55 dB, Lorentzian linewidth < 30...
Among the final shots at Nova laser [Campbell et al., Rev. Sci. Instrum. 57, 2101 (1986)] was a series testing VISAR (velocity interferometry system for any reflector) technique that will be primary diagnostic timing shocks in NIF (National Ignition Facility) ignition capsule. At Nova, worked over range of shock strengths and with precision required job—shock velocities liquid D2 from 12 to 65 μm/ns better than 2% accuracy. images showed stronger overtaking weaker ones, which is basis plan...
A technique has been developed that allows the measurement of equations state low-atomic-number materials in regimes extremely high pressure. Using this we have obtained absolute multimegabar measurements on principal Hugoniots low- $Z$ solids, including data polystyrene up to 40 Mbar (60 times previous absolutely measured pressure) and beryllium at pressures 15 Mbar. The were able differentiate between existing theoretical models. confirm several as 65
Pyrometric measurements of single-shock-compressed liquid deuterium reveal that shock front temperatures T increase from 0.47 to 4.4 eV as the pressure P increases 31 230 GPa. Where becomes both conducting and highly compressible, 30< or =P< =50 GPa, is lower than most models predict T<<T(Fermi), proving a degenerate Fermi-liquid metal. At P>50 Gpa, where optical reflectivity saturated, there an in rate with P.
We describe a theoretical model for the linear optical gain properties of quantum wire assembly and compare it to well known case dot assembly. also present technique analyze an amplifier using bias dependent room temperature amplified spontaneous emission spectra. Employing this procedure in conjunction with model, we demonstrate that InAs/InP dash structures have quantum-wire-like characteristics. The was used extract net coefficient, differential gain, relative current component...
Wavelength conversion based on four-wave mixing (FWM) and cross-gain modulation (XGM) is experimentally demonstrated for the first time in a 1550-nm InAs-InP quantum-dash semiconductor optical amplifier. Continuous-wave FWM with symmetric efficiency dependence detuning direction mediated short-pulse wavelength are demonstrated. Using XGM, we have successfully implemented over 10 THz error-free data of 2.5-Gb/s sequence 7.5 THz. The pulsed XGM experiments suggest that adjacent regions within...
A fully integrated 800 Gbps PAM-4 2×FR4 and DR8 silicon photonics transmitter with eight heterogeneously DFB lasers is demonstrated for data center applications over a temperature range of 0~70°C reach up to 2 km.
ABSTRACT The evolution of oxygenic photosynthesis in the Cyanobacteria was one most transformative events Earth history, eventually leading to oxygenation Earth’s atmosphere. However, it is difficult understand how earliest functioned or evolved on early part because we do not their ecology, including environments which they lived. Here, use a cutting-edge bioinformatics tool survey nearly 500,000 metagenomes for relatives taxa that likely bookended identify modern these organisms live....
A direct measurement is presented that quantifies prepulse reduction in an intense, ultrashort pulse on reflection from a high-density plasma created SiO(2) target at Brewster's angle. The contrast between the intense and energy was improved by factor of >625. Pulse-width reduction, spectral broadening, spatial filtering are also observed reflected pulse.
Journal Article NEWS SELECTION PATTERNS AMONG IOWA DAILIES Get access DAVID GOLD, GOLD David Gold is Chairman of the Department Sociology at University CaliforniaSanta Barbara Search for other works by this author on: Oxford Academic Google Scholar JERRY L. SIMMONS Jerry Simmons Assistant Professor Illinois Public Opinion Quarterly, Volume 29, Issue 3, FALL 1965, Pages 425–430, https://doi.org/10.1086/267342 Published: 01 January 1965
A monolithic dual‐polarisation quadrature phase shift keying transmitter is demonstrated for operation at 2.25 Tbit/s over 40 wavelengths and 1 THz of spectral bandwidth. The single‐chip InP‐based employs tunable distributed feedback lasers, 80 nested Mach‐Zehnder modulators other elements to provide more than 1700 integrated photonic functions.
The Nova laser [E. M. Campbell, Laser Part. Beams 9, 209 (1991)] was used to shock-compress liquid deuterium and obtain new principal Hugoniot measurements of density pressure between 0.3 2.1 Mbar. In this pressure-density region, is predicted transform from a molecular insulating fluid an atomic conducting fluid. data show rapid increase in 0.6 g/cc at Mbar, 1 suggestive such transition. observed sixfold compression near Mbar larger than by many widely equation state models.
The technique of self-induced plasma shuttering can be used to suppress prepulse energy from an ultrashort pulse. If a femtosecond pulse is incident upon transparent target, the leading edge passes through while peak reflects owing ionization breakdown at surface. We describe fluid jet, enclosed in vacuum chamber, that allows this high repetition rates. jet has excellent stability and fast (~500 micros) recovery time. At normal incidence, we demonstrate reflection efficiency 70% with...
A 100Gbps CWDM4 silicon photonics transmitter with four heterogeneously integrated distributed feedback lasers on 20 nm wavelength grids has been demonstrated for 5G wireless front-haul applications over a temperature range of −20°C to 95°C.
A methodology is presented to characterize the nonlinear absorption loss coefficient and effective free carrier lifetime in silicon ring resonators at high intra-ring optical power density. The proposed uses a continuous-wave pump-probe measurement capture distortion-free transmission spectra regime of absorption. measured using this method 30-40% higher than that obtained with single high-power laser. also reveals sharply increases beyond ∼11.6 mW bus waveguide for design highest...