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A new endless (resetting-free) polarization control scheme called "polarization recombining" is proposed and verified experimentally. The system consists of a polarization rotator, a polarization beam splitter (a Wollaston prism), a 90° linear polarization rotator, an endless phase shifter, and a beam combiner. The important feature of this system is that the state-of-polarization (SOP) of the polarization-controlled light is always linear with a fixed inclination angle regardless of changes in the SOP of the input light. Such a characteristic is achieved without the use of a polarimeter which is undesirable in a practical system. This feature is particularly attractive for automatic polarization control implementation in the 90° optical hybrid receiver. A simulated self-homodyne DPSK system experiment for such receiver utilizing this polarization control scheme is also demonstrated and the receiver sensitivity fluctuation is found to be within the range of 0.5 dB at 200 Mbit/s.

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