  We demonstrate that a photon echo can be implemented by all-optical means
using an array of on-chip high-finesse ring cavities whose parameters are
chirped in such a way as to support equidistant spectra of cavity modes. When
launched into such a system, a classical or quantum optical signal -- even a
single-photon field -- becomes distributed between individual cavities, giving
rise to prominent coherence echo revivals at well-defined delay times,
controlled by the chirp of cavity parameters. This effect enables long storage
times for high-throughput broadband optical delay and quantum memory.
