Sub-optical-cycle waveform synthesis of light

Here we demonstrate, for the first time, synthesis of intense (multi-GW scale), sub-optical-cycle controlled, isolated bursts of light. Key elements of our approach include (a) the efficient generation of coherent ultrawideband pulses via their nonlinear propagation in gas-filled, pressurized hollow-core fibres and which span spectrally more than 1.5 octaves (340-1100 nm). (b) The spectral division of these pulses to create three (or more) in a prototype synthesizer based on specially designed, dichroic optics and chirped mirrors, (c) Coherent spatial and temporal superposition of these pulses, upon their temporal compression to few-cycle durations with chirped mirrors, to synthesize sub-optical-cycle waveforms by manipulating their relative phases and amplitudes.