A TEMPORAL photonic crystal?

Thousands of papers were published about photonic crystals, namely artificial composites with spatial periodicity. In this talk I will explore the properties and possible realization of temporal photonic crystals (TPCs) with periodicity in time. Specifically, I assume that either the permittivity and/or permeability of a (spatially uniform) medium is a periodic function of time. This gives rise to interesting behavior such as parametric resonances that depend on the thicknes of the dynamic slab and to pulse transmission with faster-than-light partial pulses (that correspond to harmonics of the modulation frequency). Finally, I will show that TPCs can be realized in the microwave regime by means of transmission lines with capacitors (varactors) and/or inductors that are temporally periodic.