C- and L-band DWDM transmission over anti-resonant hollow-core fiber with a capacity-distance product of 73.4 Pbit/s·km.

Anti-resonant hollow-core fiber (AR-HCF) is a novel transmission medium that significantly mitigates the capacity limitation caused by fiber nonlinear effects. This provides what we believe to be a new technical approach for high-capacity and low-latency optical networks. In this paper, we evaluate the transmission performance of AR-HCF in broadband and long-haul dense wavelength-division multiplexing (DWDM) systems. Based on AR-HCFs with a single span of 100 km, 20-Gbaud dual-polarization quadrature phase-shift keying (DP-QPSK) signals are transmitted over 2,500 km (25 loops) across 367 DWDM channels in the C- and L-band, achieving a record capacity-distance product of 73.4 Pbit/s·km (367 × 80-Gbit/s × 2,500-km). Experimental results indicate that the transmission can reach a maximum distance of 3,700 km for some channels over the C-band, while all channels exceed 2,600 km. Without employing wavelength-selective switches (WSSs) to suppress out-of-band noise, the L-band exhibits an approximately 1-dB optical signal-to-noise ratio (OSNR) penalty compared to the C-band after 2,500-km transmission. Bit-error rates (BERs) for the 367 DWDM channels are below the 15% hard-decision forward error correction (HD-FEC) overhead threshold. These results provide a systematic experimental evaluation of DWDM transmission over AR-HCFs, proving great potential as a powerful tool in applications such as data centers, 6G optical networks, and low-latency computing clusters.