Light polarization modulation based on microfiber and magnetic fluid

We experimentally demonstrate a new method for modulating the light polarization state of the fiber. Both of the light polarization degree and polarization direction can be modulated. In the experiment, microfiber is immersed into the magnetic fluid (MF). When there is external magnetic field, magnetic nanoparticles of the MF generate magneto-optical dichroism and a non-circular symmetric distribution around microfiber. The light polarization state is modulated when the light passes the microfiber. When the external magnetic field rotates from 0
^o
to 360
^o
, the light polarization modulating exerts good polarization direction response.