| 摘要 |
Simultaneous recovery of several different clock signals (SIN,A , SIN,B) is based on coupling an optical input signal (SIN) into an optical resonator (OR1) matched with at least four spectral peaks ( REF,A , SIDE,A , REF,B, 5 SIDE,B) of the input signal (SIN). The input signal (SIN) having arbitrary polarization is divided by a polarizing splitter into a first signal (S1) having horizontal (H) polarization and a second signal (S2) having vertical (V) polarization. The polarization of the first signal (S1) is 10 rotated 90 degrees such that the polarization of the first signal (S1) is parallel to the vertical (V) polarization second signal (S2). Both vertically (V) polarized signals (S1, S2) are passed through the same optical resonator (OR1) in opposite directions (DR1, DR2), and they are combined after passing through the resonator (OR1) in order to 15 form an output signal (SOUT). The spectral separation between the first peak (REF,A ) and the second peak (SIDE,A ) is equal to a first clock frequency ( CLK,A ), and the spectral separation between the third peak (REF,B) and the fourth peak (SIDE,B) is equal to a second clock frequency (CLK,B). The resonator (OR1) stores optical energy and 20 provides an output also when the input signal (SIN) is zero. Thus, the output signal (SOUT) comprises a first recovered clock signal (SCLK,A ) which exhibits continuous beat at said first clock frequency (CLK,A ), and a second recovered clock signal (SCLK,B) which exhibits continuous beat at said first clock frequency(CLK,B).Only vertically (V) polarized light is 25 passed through the resonator (OR1). Thus, variations in the polarization of the input signal (SIN) do not require continuous re- adjustment of the resonator (OR1). |
