Reflection of short polarized optical pulses from periodic and aperiodic multiple quantum well structures

We study the reflection of polarized optical pulses from resonant photonic structures formed by periodic, Fibonacci, and gradient sequences of quantum wells. The form and polarization of the reflected pulse are shown to be determined by the structure design and optical length. In structures with periodic quantum well arrangement, the response to ultrashort pulse is an optical signal with a sharp rise followed by an exponential decay or Bessel beats depending on the structure length. The duration of reflected pulses nonmonotonically depends on the number of quantum wells reaching the minimum for a certain structure length which corresponds to the transition from superradiant to photonic-crystalline regime. We also study the conversion of pulse polarization in the longitudinal external magnetic field which splits the exciton resonance. Comparing periodic, Fibonacci, and gradient structures we show that the latter are more efficient for the conversion from linear to circular polarization.