The non-collinear superposition of a laser beam with a weak second harmonic beam produces laser wavefronts that oscillate angularly in time, at the laser frequency. We have used the resulting ultrafast (attosecond) photonic streaking to characterize, both in space and time, the attosecond pulses produced from plasma mirrors at intensities up to $10^{19}$ W/cm$^2$.
First experimental results on the angular streaking of attosecond pulse trains from relativistically oscillating mirrors are presented leading to the mapping of the temporal structure of the attosecond pulse train into emission angle.
We present laser waveform-dependent extreme ultraviolet high-order harmonic radiation from a relativistic plasma mirror that supports a well-isolated attosecond pulse. Spectral interferometry reveals information about its temporal structure and the relativistic generation mechanism.
We present experiments using a relativistic-intensity 2-colour multi-cycle and 1.3-cycle laser fields to drive high-harmonic generation (HHG) from surface plasmas with controlled electron density gradient. Both examples demonstrate attosecond control over the underlying collective electron dynamics.
A method for the synthesis of ultrashort pulses in the deep UV is demonstrated, which utilizes the temporal and spatial harmonics that are generated by two noncollinear IR-VIS pulses in a thin MgF$_{2}$ plate.
We demonstrate the first cavity-enhanced high-harmonic generation with spatiotemporal coupling, offering the prospects of gating isolated attosecond pulses at multi-10-MHz repetition rates and a highly efficient, photon-energy- and power-scalable output coupling mechanism.
