Polarization Maintaining Fibre Loop Mirror for NRZ-to-PRZ Conversion in All-Optical Clock Recovery

We propose a novel configuration for clock extraction by converting the NRZ data into the PRZ data and by employing a polarization-maintaining fibre loop mirror (PMFLM) which is usually used as an optical comb filter. It is found that the PMFLM can simply be constructed by a polarization controller and polarization-maintaining fibre (PMF). We theoretically analyse the principle of PMFLM for the NRZ-to-PRZ conversion. Experimentally we demonstrate 10 Gbit/s all-optical clock recovery through our proposed setup. It is shown that recovered clock signal with an extinction ratio above 10 dB can be achieved.