96 research outputs found
Accelerating Plasma Mirrors to Investigate Black Hole Information Loss Paradox
The question of whether Hawking evaporation violates unitarity, and therefore
results in the loss of information, remains unresolved since Hawking's seminal
discovery. So far the investigations remain mostly theoretical since it is
almost impossible to settle this paradox through direct astrophysical black
hole observations. Here we point out that relativistic plasma mirrors can be
accelerated drastically and stopped abruptly by impinging ultra intense x-ray
pulses on solid plasma targets with a density gradient. This is analogous to
the late time evolution of black hole Hawking evaporation. A conception of such
an experiment is proposed and a self-consistent set of physical parameters is
presented. Critical issues such as black hole unitarity may be addressed
through the measurement of the entanglement between the Hawking radiation and
their partner modes.Comment: 5 pages, 2 figure
Probing the quantum vacuum with ultra intense laser pulses
This article presents: 1) The theoretical background of strong field physics
and vacuum structure and stability; 2) The instrumental developments in the
area of pulse lasers and considers the physics case for ultra intense laser
facilities; and 3) Discussion of the applied and fundamental uses of
ultra-intense lasers.Comment: Contribution in Special Topics issue for IZEST, 12 pages incl 1
figure. Contains extended citation list compared to published versio
Superstrong field science
Over the past fifteen years we have seen a surge in our ability to produce high intensities, five to six orders of magnitude higher than was possible before. At these intensities, particles, electrons and protons, acquire kinetic energy in the mega-electron-volt range through interaction with intense laser fields. This opens a new age for the laser, the age of nonlinear relativistic optics coupling even with nuclear physics. We suggest a path to reach an extremely high-intensity level 1026â28âW/cm21026â28W/cm2 in the coming decade, much beyond the current and near future intensity regime 1023âW/cm2,1023W/cm2, taking advantage of the megajoule laser facilities. Such a laser at extreme high intensity could accelerate particles to frontiers of high energy, tera-electron-volt and peta-electron-volt, and would become a tool of fundamental physics encompassing particle physics, gravitational physics, nonlinear field theory, ultrahigh-pressure physics, astrophysics, and cosmology. Such a laser intensity may also be very beneficial to an alternative, more direct approach of fast ignition in laser fusion. We suggest a new possibility to explore this. © 2002 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87922/2/423_1.pd
FORUM on superstrong fields and high energy physics
© 2002 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87923/2/459_1.pd
Radiation back-reaction in relativistically strong and QED-strong laser fields
The emission from an electron in the field of a relativistically strong laser
pulse is analyzed. At the pulse intensities of \ge 10^{22} W/cm^2 the emission
from counter-propagating electrons is modified by the effects of Quantum
ElectroDynamics (QED), as long as the electron energy is sufficiently high: E
\ge 1 GeV. The radiation force experienced by an electron is for the first time
derived from the QED principles and its applicability range is extended towards
the QED-strong fields.Comment: 4 pages, 4 figure
Ultrahigh intensity laser for laser wakefield acceleration
The next generation of high peak power CPA laser systems will be improved in compactness, simplicity, and cost. Yb:glass is a suitable choice for the amplifier medium in such a laser system necessary for an all-optical GeV accelerator. © 1997 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87564/2/68_1.pd
1.4 ps riseâtime highâvoltage photoconductive switching
We report on the generation of 825 V electrical pulses with 1.4 ps rise time and 4.0 ps duration using a pulseâbiased lowâtemperatureâgrown GaAs photoconductive switch triggered by an amplified femtosecond dye laser. Dependence of the pulse shape on both electric field and optical energy is observed and discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70925/2/APPLAB-59-12-1455-1.pd
Subpicosecond photoresponse of carriers in lowâtemperature molecular beam epitaxial In0.52Al0.48As/InP
Femtosecond timeâresolved reflectivity and photoconductive switching measurements have been made of In0.52Al0.48As grown by molecular beam epitaxy on (100)âInP substrates at growth temperatures ranging from 150 to 480â°C. A response/switching time of âŒ400 fs is measured in the sample grown at 150â°C. Temperatureâdependent measurements shed light on the nature of the material producing the ultrafast response.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71065/2/APPLAB-57-15-1543-1.pd
Optical properties of highâquality InGaAs/InAlAs multiple quantum wells
We have measured the narrowest halfâwidth at halfâmaximum photoluminescence linewidth of 2.8 meV, in 40âperiod latticeâmatched In0.53Ga0.47As/In0.52Al0.48As multiple quantum wells, grown by molecularâbeam epitaxy with growth interruption. A simple analysis of the linewidth suggests that the structure has near perfect interfaces. Temperatureâdependent photoluminescence linewidth data indicate impurity incorporation due to the growth interruption. However, the high quality of the multiple quantum well is not impaired as is seen in the roomâtemperature absorption data, where excitonic features up to n=3 sublevel are clearly seen. Carrier lifetime in this multipleâquantumâwell system has been measured, we believe for the first time, using the picosecond photoluminescence correlation technique. A lifetime of 860 ps is obtained, which is similar to the value obtained for highâquality GaAs/AlGaAs and In0.53Ga0.47As/InP quantum wells. This further confirms the high quality obtained in this ternary material system using growth interruption.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70406/2/JAPIAU-69-5-3219-1.pd
- âŠ