Speaker
Description
Erbium-doped solid-state crystals have emerged as a promising platform for quantum memories in quantum networks and quantum technologies, due to the telecom compatible 1.5 µm transition. In recent years, excellent performance has been achieved in these systems: efficiencies up to 80%, storage of 70 temporal modes [1], and hyperfine coherence times of 3 seconds in a bulk crystal [2]. However, these memories still fall short of the requirements for commercial applications (efficiency > 90% [3], MHz data rates [1]) and suffer from free-space coupling losses. The current performance is reaching the limits of simple free-space experiment geometries. Cavity-enhanced memories have been shown to exceed free-space performance, theoretically allowing unity efficiency.
We have developed a cavity-enhanced memory based on a fibre ring cavity incorporating a fibre-coupled bulk 167Er:Y2SiO5 crystal. Cavity coupling is controlled using an electro-optic variable coupler, which allows fully programmable optical feedback to the crystal. Cavity stability is achieved using low-loss in-fibre phase and polarisation controllers. This design is constructed with commercially available telecom fibre-optic components, using a simple architecture to achieve efficient optical coupling, and memory performance, without the need for bespoke fabrication.
Here we present the first cavity-enhanced solid-state memory with dynamic optical feedback. Preliminary results show improved efficiencies over the free-space experiment with substantially improved optical coupling.
References
[1] J. Stuart, arXiv:2409.12503
[2] J. Lang, in preparation.
[3] W. Tittel 2010, 10.1002/lpor.200810056.
| I am the presenting author | Yes |
|---|