  In the propagation of optical pulses through dispersive media, the frequency
degree of freedom acts as an effective decohering environment on the
polarization state of the pulse. Here we discuss the application of open-loop
dynamical-decoupling techniques for suppressing such a polarization decoherence
in one-way communication channels. We describe in detail the experimental proof
of principle of the "bang-bang" protection technique recently applied to flying
qubits in [Damodarakurup et al., Phys. Rev. Lett. 103, 040502]. Bang-bang
operations are implemented through appropriately oriented waveplates and
dynamical decoupling is shown to be potentially useful to contrast a generic
decoherence acting on polarization qubits propagating in dispersive media like,
e.g., optical fibers.
