Enhanced CSPR for a multichannel Kramers-Kronig receiver by self-seeded stimulated Brillouin scattering

We demonstrate carrier-to-signal power ratio (CSPR) enhancement by self-seeded stimulated Brillouin scattering to improve the performance of Kramers-Kronig (KK) detection for multichannel single-sideband (SSB) signals. By virtue of low-CSPR transmission and high-CSPR detection, our proposed scheme effectively advances system performance by reducing propagation-induced distortion while maintaining the minimum phase condition. We experimentally demonstrate the improvement in CSPR and bit error rate of 5×10-Gbaud 16-QAM SSB signals by applying the carrier recovery block after 80-km transmission. Under optimum pump power, the average Q factor improvement of all five channels is 3.0 dB. We also analyze the performances of different channels and the major limiting factor. The results verify that our scheme offers a promising solution to enhance SSB self-coherent KK detection in wavelength-division multiplexing systems.