High-energy pulse synthesis with sub-cycle waveform control for strong-field physics
Over the last decade, control of atomic-scale electronic motion by non-perturbative optical fields has broken tremendous new ground with the advent of phase-controlled high-energy few-cycle pulse sources1. The development of close to single-cycle, carrier-envelope phase controlled, high-energy optical pulses has already led to isolated attosecond EUV pulse generation2, expanding ultrafast spectroscopy to attosecond resolution1. However, further investigation and control of these physical processes requires sub-cycle waveform shaping, which has not been achievable to date. Here, we present a light source, using coherent wavelength multiplexing, that enables sub-cycle waveform shaping with a two-octave-spanning spectrum and a pulse energy of 15 µJ. It offers full phase control and allows generation of any optical waveform supported by the amplified spectrum. Both energy and bandwidth scale linearly with the number of sub-modules, so the peak power scales quadratically. The demonstrated system is the prototype of a class of novel optical tools for attosecond control of strong-field physics experiments.