Soliton-effect self-compression: limits and high repetition rate scaling

Soliton dynamics can be used for compressing optical pulses to few fs durations over a wide spectral range, and can be conveniently scaled in gas-filled hollow-core fibre by suitable design of the fibre structure and choice of gas [1] , [2] . In this fashion, similar patterns of pulse propagation can be obtained at pulse energies ranging from a few tens of nJ up to the mJ-level, and for pulse durations τ 0 up to hundreds of fs. The dynamics are controlled by the soliton order N and the spectral distance of the pulse frequency ν 0 from the zero dispersion frequency ν ZD . Here we report the existence of a region in ( N , ν ZD , τ 0 )-space where soliton-effect self-compression is optimal, provided the transmission loss of the fibre is negligible. We assess the limits set by modulational instability (MI) [3] , self-focusing (SF), and photoionisation (ION) [1] and derive a new limit set by third-order dispersion (TOD). By numerical simulation (not shown) we validate these limits, observing that if they are exceeded the compression quality degrades. Furthermore, we investigate, both theoretically and experimentally, scaling to MHz-level repetition rates, when inter-pulse effects cannot be neglected.