All-optical signal regeneration and coherent data receiving aided by integrated Kerr frequency comb

Abstract

Integrated dissipative Kerr soliton optical frequency comb 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 the independent lasers. In the scenario 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. Also, in the scenarios of all-optical signal regeneration, a multi-wavelength coherent laser array is also needed to provide the coherent pump fields that enable phase-sensitive parametric amplification of the degraded data signals and constitute regenerative phase transfer functions. In this talk, we will introduce our recent experiments that implement re-generation of a Kerr soliton microcomb that faithfully clones the frequency and phase coherence of another microcomb. We show that such coherence-cloned carrier and LO microcombs can greatly facilitate coherent data receiving by making DSP-based compensations for carrier-LO frequency offsets and phase drifts substantially easier, and at most 1000 times more energy-saving, comparing with a system adopting individual laser carriers and LOs. Moreover, we will also discuss that the coherence-cloned Kerr microcombs can be used to implement multi-channel, configurable all-optical signal regeneration in nonlinear silicon waveguide, phase regenerations of two channel BPSK signals are demonstrated with prominent signal quality improvements. Our work reveals that, in addition to providing a multitude of laser tones, regulating the frequency and phase of Kerr soliton microcombs among data transmitters, regenerators, receivers within an optical network can significantly improve the network performance in terms of signal quality, power consumption, and simplicity.