Ultrahigh-Intensity Lasers: Physics of the Extreme on a Tabletop

Abstract

Over the past ten years, laser intensities have increased by more than four orders of magnitude to reach enormous intensities of 1020 W/cm2. The field strength at these intensities is on the order of a teravolt per centimeter, or a hundred times the Coulombic field binding the ground state electron in the hydrogen atom. The electrons driven by such a field are relativistic, with an oscillatory energy of 10 MeV. At these intensities, the light pressure, P = I/c, is extreme, on the order of giga- to terabars. The laser interacting with matter—solid, gas, plasma—generates high-order harmonics of the incident beam up to the 3 nm wavelength range, energetic ions or electrons with mega-electron-volt energies (figure 1), gigagauss magnetic fields and violent accelerations of 1021 g (g is Earth's gravity). Finally, the interaction of an ultraintense beam with superrelativistic particles can produce fields approaching the critical field in which an electron gains in one Compton wavelength an energy equal to twice its rest mass. Under these conditions, one observes nonlinear quantum electrody-namical effects. In many ways, this physical environment of extreme electric fields, magnetic fields, pressure, temperature and acceleration can be found only in stellar interiors or close to the horizon of a black hole. It is fascinating to think that an astrophysical environment governed by hydrodynamics, radiation transport and gravitational interaction can be re-created in university laboratories for extremely short times, switching the role of the scientist from voyeur to actor.

Advanced Channeling Technologies in Plasma and Laser Fields

“…Studying the propagation of nonlinear plasma electromagnetic waves being of great practical interest due to the progress in laser technologies [84,85] has shown that powerful ultrashort laser pulses propagating in a plasma can accelerate the plasma electrons to ultra-relativistic energies (so called "laser wakefield acceleration") [86][87][88][89]. Considering the problem of powerful ultrashort laser pulse interaction with a plasma based on numerical simulations, a model for a strongly nonlinear regime of interaction of intense laser pulses with plasmas has been proposed.…”

Trapping, compression, and acceleration of an electron bunch in the nonlinear laser wakefield

“…Last years CPA technique permitted the production of subpicosecond laser pulses of multiterawatt power with peak intensities exceeding 10 20 W/cm 2 [2]. With intensities as such we practically have to do with a new interaction range of laser radiation with matter, where the role of the nonlinear effects is often essential.…”

Short-Pulse Laser-Produced Plasmas

“…One of these advances is the implementation of the Chirped Pulse Amplification (CPA) technique [1] which has created new opportunities in the domain of ultra-intense and ultrafast laser physics. The interactions of ultra high-intensity laser pulses with matter have opened the field of optics in relativistic plasmas, a new topic of high-field science presented in comprehensive reviews [2,3]. Indeed, intense lasers have been used to accelerate beams of electrons [4] and protons [5] to energies of several megaelectronvolts in distances of only microns.…”