Abstract: A driver (1) for a plasma particle accelerator includes a plasma (10) and laser system(s) (2) that generate first and second pulses. The first pulse (4) has a duration less than the electron plasma period. The second pulse (6) is temporally smooth and has a duration greater than the electron plasma period and less than the ion plasma period. The first pulse generates a plasma wake and the second pulse interacts with the wake to form red and blue-shifted sidebands. The driver also includes a dispersive optical device (20) that introduces a chromatic dispersion to shift the spectral phases of the red and blue-shifted sidebands, to temporally shift them relative to each other, so as to form coincident pulses (22) for generating a plasma wake in a plasma particle accelerator (26).

Abstract: A high harmonic optical generator comprising a laser arrangement for emitting a beam of polarized radiation at a fundamental frequency and an optical waveguide having a hollow core for a gaseous harmonic generation medium for the generation of high harmonics of the fundamental frequency, the optical waveguide having an optical propagation axis along the hollow core, the laser arrangement is configured to couple the beam of polarized radiation along the propagation axis of the hollow core optical waveguide to provide a beam of optical driving radiation for the high harmonic generation, the optical driving radiation having a plane of polarization that rotates about the propagation axis.

Abstract: A high harmonic optical generator comprising a laser arrangement for emitting a beam of polarized radiation at a fundamental frequency and an optical waveguide having a hollow core for a gaseous harmonic generation medium for the generation of high harmonics of the fundamental frequency, the optical waveguide having an optical propagation axis along the hollow core, the laser arrangement is configured to couple the beam of polarized radiation along the propagation axis of the hollow core optical waveguide to provide a beam of optical driving radiation for the high harmonic generation, the optical driving radiation having a plane of polarization that rotates about the propagation axis.