11.2 Gbps 100-meter free-space visible light laser communication utilizing bidirectional reservoir computing equalizer

• DOI: 10.1364/oe.506056
• Publication Date: 2023-11-28T19:00:17Z
• Authors: Zhilan Lu; Jifan Cai; Zengyi Xu; Yuning Zhou; Junwen Zhang; Chao Shen; Nan Chi
• Keywords: Free-Space Optical Communication; Adaptive equalizer; SIGNAL (programming language)

In this paper, we introduce an innovative post-equalization technique leveraging bidirectional reservoir computing (BiRC), and apply it to waveform-to-symbol level equalization for visible light laser communication the first time. This strategy is more resistant nonlinearities compared traditional equalizers like least mean square (LMS) equalizer, while requiring less training time fewer parameters than neural network (NN) -based equalizers. Through approach, successfully conduct a 100-meter transmission of 32-amplitude phase shift keying (32APSK) signal using green operating at wavelength 520 nm. Remarkably, our system achieves high data rate 11.2 Gbps, all maintaining satisfying bit error (BER) below 7% hard decision forward correction (HD-FEC) threshold 3.8E-3.