Generation of few-cycle radially-polarized infrared pulses in a gas-filled hollow-core fiber

We perform a numerical study for temporally compressing radially-polarized (RP) infrared pulses in a gas-filled hollow-core fiber (HCF). The dynamic transmission and nonlinear compression of RP pulses centered at wavelengths of 0.8 μ, 1.8 μ, 3.1 μ, and 5.0 μ in HCFs are simulated. By comparing the propagation of pulses with the same optical cycles and intensity, we find that under proper conditions these pulses can be compressed down to 2-3 cycles. In the transverse direction, the spatiotemporal beam profile ameliorates from 0.8-μ to 1.8-μ and 3.1-μ pulses before the appearance of high-order dispersion. These results show an alternative method of scaling generation for delivering RP infrared pulses in gas-filled HCFs, which can obtain energetic few-cycle pulses, and will be beneficial for relevant researches in the infrared scope.