# All-optical photon echo and memory on a chip

## TL;DR

This paper demonstrates an all-optical photon echo and memory on a chip using chirped high-finesse ring cavities, enabling long storage times for broadband optical signals and quantum memory applications.

## Contribution

It introduces a novel on-chip all-optical photon echo scheme using chirped cavity arrays supporting equidistant spectra.

## Key findings

- Achieved prominent coherence echo revivals at controlled delay times.
- Enabled long storage times for broadband optical delay.
- Demonstrated potential for quantum memory applications.

## Abstract

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.