Multipass-cell-based post-compression of radially and azimuthally polarized pulses to the sub-two-cycle regime

Nonlinear spectral broadening of radially and azimuthally polarized pulses by using the multipass cell technique is proposed and investigated with numerical simulations. The scheme features post-compression of optical pulses from 30 fs down to sub-5 fs centered around 800 nm wavelength with negligible beam distortion and high spectral broadening homogeneity. The performance of the multipass cell is studied with solid-state and gaseous media at μJ and mJ energy levels, respectively. The simulations show that dispersion management in the cell is crucial to obtain sub-two-cycle pulses, while dispersive coatings are considered. It is also shown that multipass cells with silver mirrors provide an alternative option that eases the requirement for dispersion control with an acceptable sacrifice on the net transmission. The sub-two-cycle radially/azimuthally polarized laser pulses are of great interest for generation of radially/azimuthally polarized isolated attosecond extreme ultraviolet pulses and for novel schemes of electron acceleration.