Nonlinear pluggable optics: digital signal processing-free intensity modulated direct detection links using analog photonic next generation reservoir computing

In this work, we propose and simulate a nonlinear pluggable optic (NLPO) transceiver that combines the low latency and low power consumption of linear pluggable optics (LPO) with the range and robustness of digital signal processing (DSP)-based transceivers. The proposed NLPO uses an analog photonic next-generation reservoir computing (NGRC) architecture, constructed on a photonic integrated circuit (PIC), to compensate for electrical-domain distortions and optical-channel impairments from chromatic dispersion and moderate Kerr nonlinearity. Focusing on a simulated 50 GBd PAM-4 link, we find that the NGRC-based NLPO not only extends the LPO range, but can actually outperform DSP based on industry-standard Volterra nonlinear equalizers. Our simulations reveal two key advantages compared to DSP-based Intensity modulation/direct detection (IM/DD) links: (1) the NGRC can take advantage of the optical phase information without requiring a local oscillator and (2) the NGRC can optically sample the transmitted data well above the symbol rate without requiring high-bandwidth electronics. This work showcases the potential for photonic NGRCs to outperform state-of-the-art digital solutions in real-world applications and opens a path to low-latency, lower-power IM/DD links at ranges of 10s of km.