Fast and chaotic WDM all-optical polarization scrambler

The ability to randomly scramble the state-of-polarization (SOP) of a light beam is an important issue that encounters numerous applications in photonics. Polarization scrambling (PS) is indeed mainly implemented to ensure polarization diversity in optical telecommunication systems so as to combat deleterious polarization effects and provide mitigation of polarization mode dispersion (PMD) and polarization dependent loss or gain [1]. Here, we report a simple and efficient all-optical polarization scrambler based on the nonlinear interaction in a 5.3 km-long optical telecommunication fiber between a signal beam and its backward replica which is generated and amplified by a reflective loop (Fig. la). The basic principle of this device was first established in [2] in order to demonstrate a transparent method of temporal spying and concealing process for optical communications. Indeed, it consists in an additional operating mode, namely the chaotic mode, of the device called Omnipolarizer [3], originally conceived to operate as an all-optical polarization attractor and beam splitter [4]