Improvement of 112/224-Gbps optical coherent transmission systems by pre-filtering optimization

Abstract

We provided an approach to improve 112-Gb/s RZ-PDM-QPSK and 224-Gb/s RZ-PDM-16QAM systems performance, based on the matched-filtering principle. An optical pre-filtering optimization at the transmitter side was performed, evaluating different filter profiles. A 33-GHz Nyquist-like optical filter was found to be the best solution to improve both 112-Gb/s and 224-Gb/s systems performance. We also performed a back-to-back evaluation in order to obtain the OSNR performance for the optimized systems. Improvements of 0.5 dB and 1 dB in OSNR performance were found for 112-Gb/s RZ-PDM-QPSK and 224-Gb/s RZ-PDM-16QAN, respectively.