  We demonstrate an all-optical phase regeneration technique based on Kerr
soliton combs, which can realize degraded quaternary phase shift keying (QPSK)
signal regeneration through phase-sensitive amplification. A Kerr soliton comb
is generated at the receiver side of optical communication systems based on a
carrier recovery scheme and is used as coherent dual pumps to achieve phase
regeneration. Our study will enhance the relay and reception performance of
all-optical communication systems.
