  The polarizations of optical fields, besides field intensities, provide more
degrees of freedom to manipulate coherent light-matter interactions. Here we
propose how to achieve a coherent switch of optomechanical entanglement in a
polarized-light-driven cavity system. We show that by tuning the polarizations
of the driving field, the effective optomechanical coupling can be well
controlled and, as a result, quantum entanglement between the mechanical
oscillator and the optical transverse electric (TE) mode can be coherently and
reversibly switched to that between the same phonon mode and the optical
transverse magnetic (TM) mode. This ability of switching optomechanical
entanglement with such a vectorial device can be important for building a
quantum network being capable of efficient quantum information interchanges
between processing nodes and flying photons.
