A universal all-fiber Omnipolarizer

The all-optical control of light polarization is nowadays a fundamental issue which finds important applications in optical networks. In this field, the research has moved on the development of nonlinear methods of re-polarization of a partially coherent and initially depolarized light [1]. The main drawback of most of these devices is that they suffer from a large amount of output Relative-Intensity-Noise (RIN). However, a class of polarizers have been recently proposed which is based on the nonlinear interaction between two optical beams counter-propagating in a fiber [2]: in these devices the arbitrary state of polarization (SOP) of one of the two beams (signal) is attracted towards a specific SOP which is determined by the fixed SOP of the other beam (pump) in the fiber [2]. These polarizers turn out to be free of RIN, but they require an intense pump beam whose fixed SOP has to be also accurately stabilized.