1.2Tbs ($150 \text{Gbs} \times 2 \times 4$) PM-PAM4 WDM Transmission over 10-Km Hollow-Core Fiber at C Band Based on TFLN Automatic Polarization Controller

This paper presents a high-capacity optical interconnection solution for data centers, leveraging the synergistic integration of hollow-core fiber (HCF) and polarization multiplexing (PDM). Under the automatic polarization control algorithm, this paper innovatively proposes a multi-cycle FFT accumulation method for pilot tone extraction. By leveraging a frequency-domain signal enhancement mechanism, it overcomes the traditional limitation of pilot power ratio, achieving high-precision polarization tracking with as low as 1% resource occupation. Combined with a TFLN polarization controller for dynamic polarization drift compensation, the system achieves a total capacity of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1.2 \text{Tb}/\mathrm{s}(150 \text{Gb}/\mathrm{s} \times 4 \times 2)$</tex> PM-PAM4 signal transmission over 10 km HCF, utilizing 4-channel WDM-IM/DD transmission with a bit error rate (BER) below the 20% SD-FEC threshold of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2.4 \times 10^{-2}$</tex>. Experimental validation on an FPGA platform demonstrates polarization tracking speeds exceeding 800 rad/s while maintaining negligible signal degradation. By exploiting HCF's ultra-low nonlinearity and broad bandwidth within an intensity modulation direct detection (IMDD) framework, this work establishes a costeffective, high-compatibility Tb/s-level optical interconnection paradigm, paving the way for HCF's scalable deployment in next-generation ultra-high-speed computing networks.