There are different approaches to use; one would be to use a wave plate. However, the bandwidth of wave plates may be limited, and not rotate all wavelength components by the same amount. Also, the wave plate will introduce dispersion. A much more suitable option for use with extremely short and few-cycle pulses is the use of a polarization turning periscope, which is made from reflective optics suitable for handling the bandwidth whilst introducing only negligible dispersion. Related to: gecco / venteon / taccor
