| 摘要 |
A polarization controller, for converting an input state of polarization of a received input optical signal into an output state of polarization, comprises a plurality of polarization modifying stages for modifying the input state of polarization into the output state of polarization. Each stage allows converting an optical signal from a first state of polarization to a second state of polarization. A modulation unit modulates operation of at least one of the plurality of polarization modifying stages. A control unit receives a signal in response to the modulation, to derive therefrom an error signal indicative of a deviation of the output state of polarization from a target state of polarization, and to control operation of at least one of the plurality of polarization modifying stages in order reduce the deviation of the output state of polarization from the target state of polarization. |
