The spatio-temporal and polarisation properties of intense light is important in wide-ranging topics at the forefront of extreme light-matter interactions, including ultrafast laser-driven particle acceleration, attosecond pulse generation, plasma photonics, high-field physics and laboratory astrophysics. Here, we experimentally demonstrate modifications to the polarisation and temporal properties of intense light measured at the rear of an ultrathin target foil irradiated by a relativistically intense laser pulse. The changes are shown to result from a superposition of coherent radiation, generated by a directly accelerated bipolar electron distribution, and the light transmitted due to the onset of relativistic self-induced transparency. Simulations show that the generated light has a high-order transverse electromagnetic mode structure in both the first and second laser harmonics that can evolve on intra-pulse time-scales. The mode structure and polarisation state vary with the interaction parameters, opening up the possibility of developing this approach to achieve dynamic control of structured light fields at ultrahigh intensities.
- intense light fields
- plasma aperture
- intense laser pulse
Duff, M. J., Wilson, R., King, M., Gonzalez-Izquierdo, B., Higginson, A., Williamson, S. D. R., ... McKenna, P. (2020). High order mode structure of intense light fields generated via a laser-driven relativistic plasma aperture. Scientific Reports, 10, . https://doi.org/10.1038/s41598-019-57119-x