Fig. 1: Generation and detection of a self-compressed attosecond soliton and dispersive wave.

a, The simulated evolution of the electric field transient as it propagates along the hollow-core waveguide filled with helium gas. The colour scale shows the instantaneous frequency of the field, with the emergence of the RDW shown in purple. The dynamics of soliton self-compression and RDW emission are different in their modification of adjacent half-cycles of the field, enhancing and shortening the primary half-cycle of the waveform. b, The measurement scheme for NPS of the generated DUV RDW emission and solitons. The injection and drive pulses are colinearly focused into a gas jet. The injection pulse ionizes the gas via nonlinear photon absorption, while the DUV drive pulse accelerates the free charges. The electrodes detect the generated current.