Efficient light storage in a crystal using an Atomic Frequency Comb

TL;DR

This paper demonstrates a highly efficient, reversible light storage method in a thulium-doped crystal using an atomic frequency comb, achieving 9% efficiency and compatibility with quantum-level signals.

Contribution

The study introduces a spectral preparation technique for AFC in thulium-doped crystals, enabling efficient light storage with potential quantum applications.

Findings

Achieved 9% storage efficiency in a thulium crystal.

Demonstrated compatibility with weak quantum signals at the single-photon level.

Identified limitations due to optical thickness and preparation procedures.

Abstract

We demonstrate efficient and reversible mapping of a light field onto a thulium-doped crystal using an atomic frequency comb (AFC). Thanks to an accurate spectral preparation of the sample, we reach an efficiency of 9%. Our interpretation of the data is based on an original spectral analysis of the AFC. By independently measuring the absorption spectrum, we show that the efficiency is both limited by the available optical thickness and the preparation procedure at large absorption depth for a given bandwidth. The experiment is repeated with less than one photon per pulse and single photon counting detectors. We clearly observe that the AFC protocol is compatible with the noise level required for weak quantum field storage.