  Dissipative Kerr soliton microcomb has been recognized as a promising on-chip
multi-wavelength laser source for fiber optical communications, as its comb
lines possess frequency and phase stability far beyond independent lasers. In
the scenarios of coherent optical transmission and interconnect, a highly
beneficial but rarely explored target is to re-generate a Kerr soliton
microcomb at the receiver side as local oscillators that conserve the frequency
and phase property of the incoming data carriers, so that to enable coherent
detection with minimized optical and electrical compensations. Here, by using
the techniques of pump laser conveying and two-point locking, we implement
re-generation of a Kerr soliton microcomb that faithfully clones the frequency
and phase coherence of another microcomb sent from 50 km away. Moreover,
leveraging the coherence-cloned soliton microcombs as carriers and local
oscillators, we demonstrate terabit coherent data interconnect, wherein
traditional digital processes for frequency offset estimation is totally
dispensed with, and carrier phase estimation is substantially simplified via
slowed-down phase estimation rate per channel and joint phase estimation among
multiple channels. Our work reveals that, in addition to providing a multitude
of laser tones, regulating the frequency and phase of Kerr soliton microcombs
among transmitters and receivers can significantly improve coherent
communication in terms of performance, power consumption, and simplicity.
