Low-latency and high-speed hollow-core fiber optical interconnection at 2-micron waveband

Hollow-core fiber (HCF) has been attracting broad interests in recent decades, and has extended the communication window to longer wavelength, 2 micron. In this article, we present a demonstration of low-latency HCF short-reach optical interconnection at 2 micron, achieving a high single-lane speed of 100 Gbps. High physical speed (near vacuum-light-speed) and high information speed (100-Gbps) optical interconnection with 100-m transmission distance is experimentally achieved with error-free performance. Probabilistically shaped discrete multi-Tone (PS-DMT) modulation with entropy loading is employed to accommodate the deteriorated frequency response caused by the mode dispersion in HCF. Compared with conventional solid-core fiber (SCF), HCF contributes 30.95% (1.5-μs per kilometer) latency reduction for the physical link. The system level latency reduction is 28% for 1-km interconnection distance (11% for 100-m), with respect to a microsecond-scale switching network for typical datacenter applications. This work substantially leaps over the 100G milestone of 2-micron HCF optical interconnection, and shows the potentiality with lower latency and further higher capacity.