Ultrafast change of optical polarization predicted for XUV-irradiated diamond

The principle behind light-induced switching, which is used in modern electronic devices, is the modulation of a light signal in an externally modified medium. This allows for real-time control of the signal's phase, amplitude, or polarization. In this study, we theoretically examine transient changes in the optical polarization of wide-bandgap semiconductors irradiated by femtosecond XUV pulses to explore their potential applications in optical switching, using diamond as an example. Specifically, we observe that at a certain combination of XUV pulse parameters, an ultrafast change in the polarization angle can be triggered in diamond. These results suggest a promising approach to reversibly modulate the optical polarization in wide-bandgap semiconductors on a 100 fs timescale.