Figure 1
From: Time Circular Birefringence in Time-Dependent Magnetoelectric Media

Illustration of time refraction, time reflection and time Faraday rotation for a linearly polarized light incident upon a time wave plate with time-dependent ME coefficient Θ = βt/μ1(t0 < t t1).
At t0, the wave splits into a time refracted part and a time reflected part. The two parts are both elliptically polarized, but their major axes rotate with time. After the second interface t1, the polarization axes of the four outgoing waves have angular differences with respect to the polarization of the incident wave.