Simultaneous recovery of several different clock signals is based on coupling an optical input signal into an optical resonator matched with at least four spectral peaks of the input signal. The input signal having arbitrary polarization is divided by a polarizing splitter into a first signal having horizontal polarization and a second signal having vertical polarization. The polarization of the first signal is rotated 90 degrees such that the polarization of the first signal is parallel to the vertical polarization second signal. Both vertically polarized signals are passed through the same optical resonator in opposite directions, and they are combined after passing through the resonator in order to form an output signal. The spectral separation between the first peak and the second peak is equal to a first clock frequency, and the spectral separation between the third peak and the fourth peak is equal to a second clock frequency. The resonator stores optical energy and provides an output also when the input signal is zero. Thus, the output signal includes a first recovered clock signal which exhibits continuous beat at the first clock frequency, and a second recovered clock signal which exhibits continuous beat at the first clock frequency. Only vertically polarized light is passed through the resonator. Thus, variations in the polarization of the input signal do not require continuous re-adjustment of the resonator.
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