Simultaneous few-cycle pulse generation of the depleted pump and signal from an optical parametric amplifier

We generate few-cycle laser pulses from both the depleted pump and the signal of an optical parametric amplifier using self-phase modulation in a single hollow-core fiber. Despite the depleted pump’s poor spatial quality entering the fiber, it produces a field with less than 2.5 cycles. Moreover, we can simultaneously (same fiber) generate 4 cycle pulses from the signal. The coherent combination of both pulses allows for bandwidth spanning from 500 to 1500 nm. The geometry allows for minimal path differences of the two fields, paving a route for generating multi-octave, synthesized light transients centered in the near-infrared.