Plasma eyepieces for petawatt class lasers

Abstract

Focusing petawatt class laser beams to a variety of spot sizes for different applications is expensive in cost, labor, and space. In this paper, we propose a plasma lens to flexibly resize the laser beam by utilizing the self-focusing effect of laser in plasmas. Using a fixed conventional focusing system to focus the laser a short distance in front of the plasma, we can adjust the effective laser beam waist within a certain range, with the plasma lens acting as an adjustable eyepiece in a telescope. Such a setup is a powerful tool for laser wakefield accelerator experiments in state-of-the-art petawatt laser projects and allows for scanning focal spot parameters.

Generation of single-cycle relativistic infrared pulses at wavelengths above 20 µm from density-tailored plasmas

“…On the other hand, plasma-based methods are of particular interest for manipulation and generation of high-intensity ultrashort laser pulses, [18][19][20][21][22][23] owing to the ability of plasmas to sustain much higher power and optical intensity without the limitations imposed by the risk of damage. In recent years, there have been a number of proposals for the generation of intense single-cycle mid-IR pulses via photon deceleration of high-power relativistic short-pulse lasers in plasmas [24][25][26] or via frequency downshifting in a two-pulse laserdriven plasma optical modulator.…”

Ponderomotive Injection in Plasma Wakefield Accelerators

“…To verify this ponderomotive scattering model, we have performed a series of PIC simulations with negligible wakefield forces compared to the ponderomotive force, i.e. when a/(k p w) 2 > ∼ 1 [22], with k p the plasma wavenumber associated with the density n dope of the ionized dopant gas. We set k p w = 0.1 and focus the laser at the center of a cubic plasma volume with the size of 0.8/k p 3 , such that the length of the interaction region is shorter than the Rayleigh length to prevent a significant change of laser amplitude.…”