Demonstration of 200 Gb/s/λ PON in O-Band With High-Bandwidth TFLN Modulator

As the broadband applications continue rising, the solutions of high-speed passive optical network (PON) with large power budget are highly desired. Direct detection scheme combined with digital signal procession (DSP) has been considered as a promising candidate due to its low cost, low power consumption and simple architecture. In this paper, we experimentally demonstrate 200 Gb/s/λ and 240 Gb/s/λ time division multiplexed passive optical network (TDM-PON) downstream transmissions based on four-level pulsed amplitude (PAM-4) modulation with direct detection in O-band. A high bandwidth thin film lithium niobate modulator is adopted to generate high Baudrate optical signal at the optical line terminal (OLT) side. A pre-amplified semiconductor optical amplifier SOA is employed at the optical network unit (ONU) side to improve the power budget. Several DSP algorithms are studied to compensate the linear and nonlinear distortions. We also propose a simplified Volterra nonlinear equalizer (S-VNLE) to reduce the computational complexity. Considering the soft-decision FEC (SD-FEC) threshold (1 × 10 ⁻² ), over 29 dB and 28 dB power budgets are achieved respectively for 200 Gb/s/λ and 240 Gb/s/λ PON system after 20 km standard single mode fiber (SSMF) based on our proposed S-VNLE.