title: Pulse propagation through a slab with time-periodic dielectric function ε(t).
abstract: We describe pulse propagation through a slab with periodic dielectric function ε(t), thus extending our previous investigation for monochromatic incidence [Phys. Rev. A 79, 053821 (2009)]. Based on the concepts of phase and group delays, we prove that, for an incident quasi-monochromatic pulse, the transmitted pulse can be expressed as a superposition of partial pulses that are exact replicas of the incident pulse and that exit the slab with a time delay. These partial pulses have harmonic carrier frequencies ω c - nΩ (n is an integer, ω c is the carrier frequency of the incident pulse, and Ω = 2π/T is the slab modulation frequency). We find numerically that these partial pulses can be fast (peak velocity vn > c or vn < 0) or slow (vn << c). Further, we investigate the peak velocity v p of the outcoming pulse for several cases. We find that this peak velocity v p and the partial peak velocities vn do not diverge--as occurs to the group velocity v g of the bulk dynamic-periodic medium when ω c = Ω/2. We expect that these results could be verified in the microwave regime [see Halevi et al., Proc. SPIE 8095, 80950I (2011)].
authors.affiliation: Instituto Nacional de Astrofísica, Optica y Electrónica, Apdo. Postal 51 y 216, Puebla, Pue. 72000, Mexico.
authors.forename: Jorge R
authors.initials: JR
authors.lastname: Zurita-Sánchez
authors.forename: J H
authors.initials: JH
authors.lastname: Abundis-Patiño
authors.forename: P
authors.initials: P
authors.lastname: Halevi
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D008027:Light; D008962:Models, Theoretical; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D009991:Oscillometry / Q000379:methods; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation