Few-Optical-Cycle Solitons and Pulse Self-Compression in a Kerr Medium

In a transparent medium with instantaneous Kerr nonlinearity we find a new class of few-optical-cycle solitons and prove them to be the fundamental structures in pulse propagation dynamics. We demonstrate numerically that in the asymptotic stage of pulse propagation the input pulse splits into isolated few-cycle solitons where the quantity and their parameters are determined by the initial pulse. We generalize the concept of the high-order Schrödinger solitons to the few-cycle regime and show how it can be used for efficient pulse compression down to the single cycle duration.

Figure 1

(a) Temporal profile of the limiting soliton ($\delta ={\delta }_c$). The dashed line shows the envelope distribution. (b) Few-cycle soliton energy as a function of the pulse duration. The dashed line refers to the Schrödinger solitons.

Figure 2

Snapshots of field distribution (a) and spectrum (b) along the propagation distance. Input pulse is a few-cycle soliton with ${\omega }_o={\omega }_o^{\mathrm{in}}=1$ and $\delta ={\delta }_{\mathrm{in}}=0.32$; ${\omega }_{\mathrm{cr}}=1.5$. For output few-cycle soliton: ${\omega }_o^{(n)}=0.92$ and ${\delta }^{(n)}=0.17$. Dispersion length for these parameters is $L_d\simeq 15$.

Figure 3

(a) The input (solid line) and output (dashed line) soliton spectra corresponding to Fig. 2. (b) Dependence of the ratio of the energy of generated soliton to the input pulse energy as a function of ${\omega }_{\mathrm{cr}}$. Input pulse as in Fig. 2.

Figure 4

Snapshots of field distribution along the propagation distance for the case of $N=2.04$ and $N=4.02$. Intensity shape of the compressed pulse at $z=60$ for the case $N=2.04$ is shown in the inset.