Temporal Discontinuity for Splitting Polarization States of Light

Recently, time-varying electromagnetic structures have been extensively investigated to unveil new physical phenomena. In this direction, one of the important and historical topics is studying temporal discontinuities in these structures. Here, we consider fast changes of bianisotropic media. Specifically, we focus on introducing a temporal interface between isotropic chiral and dielectric media. We show that due to the discontinuity in time, interestingly, a linearly polarized electromagnetic wave is decomposed into forward right-handed and forward left-handed circularly polarized waves having different angular frequencies and the same phase velocities. This salient effect allows splitting light to two different polarization states with high efficiency. Hopefully, our findings will be useful as a possibility to control polarization states of light.