Signal recovery based on optoelectronic reservoir computing for high speed optical fiber communication system

Abstract Signal recovery effects of a channel equalization method based on optoelectronic reservoir computing (RC) are investigated for actual high speed optical fiber communication systems. The RC is implemented numerically by using a Mach–Zehnder intensity modulator with an optoelectronic delay feedback loop. Two optical communication systems with different transmission distances and receivers based on 25G-class optics are built in-lab. 50-Gb/s non-return-to-zero (NRZ) and four-level pulse amplitude modulation (PAM4) signals transmitted by the two systems are recovered by using optoelectronic RC and different combinations of feed-forward equalizer (FFE) with decision feedback equalizer (DFE) and maximum likelihood sequence estimation (MLSE), respectively. Under the same conditions, optoelectronic RC is better than FFED for the PAM4 signal, the sensitivity is improved by ∼ 4.9/4.6 dB compared with 123-tap FFE and 9-tap DFE. These experimental results show that the optoelectronic RC has excellent performances for signal recovery of different modulation formats and transmission systems.