Nonlinear response in high-field dielectric laser accelerators

TL;DR

This paper investigates the nonlinear effects in high-field dielectric laser accelerators, demonstrating how pulse dispersion control can optimize energy gain despite nonlinear phase shifts caused by intense laser fields.

Contribution

It introduces a method to compensate for self-phase modulation through pulse dispersion control, enhancing energy gain in dielectric laser accelerators.

Findings

Achieved 1.8 GV/m accelerating fields in experiments.

Demonstrated compensation of nonlinear phase shifts.

Showed effective energy gain optimization.

Abstract

Laser powered dielectric structures achieve high-gradient particle acceleration by taking advantage of modern laser technology capable of producing electric fields in excess of 10GV/m. These fields can drive the bulk dielectric beyond its linear response, and break the phase synchronicity between the accelerating field and the electrons. We show how control of the pulse dispersion can be used to compensate the effect of self-phase modulation and maximize the energy gain in the laser accelerator.In our experiment, a high brightness 8MeV e-beam is used to probe accelerating fields of 1.8GV/m in a 'grating-reset' dielectric structure illuminated by a 45fs laser pulse with a fluence of 0.7J/cm$^2$.