Sub-µJ, 25 eV Bandwidth Continuum Soft X-Ray Harmonic Generated by a TW-Scale Three-Channel Waveform Synthesizer

A 50-mJ three-channel parallel optical waveform synthesizer is demonstrated for generating supercontinuum high-order harmonics in the soft X-ray region. With the full active stabilization of delay jitters, relative phase jitters, and CEPs in the synthesizer, a stable intense continuum harmonic spectrum is obtained around 65 eV with a bandwidth up to 25 eV.