Optimizing the retrieval efficiency of stored light pulses.

Area of Science:

• Atomic, Molecular, and Optical Physics
• Quantum Information Science
• Laser Spectroscopy

Background:

• Electromagnetically induced transparency (EIT) enables light pulse storage in atomic coherences.
• Lambda-systems with multiple simultaneously driven transitions are used for light storage.
• Stored light pulse retrieval efficiency is sensitive to magnetic field variations.

Purpose of the Study:

• To investigate the retrieval efficiency of stored light pulses in multi-driven Lambda-systems.
• To understand the impact of stray magnetic fields on coherence times and retrieval amplitude.
• To optimize retrieval efficiency by controlling ambient magnetic fields.

Main Methods:

• Utilized laser-cooled atoms in Lambda-systems for light pulse storage.
• Employed compensation coils to minimize environmental stray magnetic fields.
• Applied controlled external magnetic fields to study their effect on retrieved pulse amplitude.

Main Results:

• Minimized stray magnetic fields led to lower retrieved probe pulse amplitude, suggesting shorter coherence times.
• Identified beating of coherences due to uncompensated DC magnetic stray fields as the cause.
• Applying an external magnetic field > stray field increased retrieved amplitude up to five-fold.

Conclusions:

• Small DC magnetic stray fields significantly degrade stored light pulse retrieval efficiency.
• Controlled application of magnetic fields can enhance retrieval amplitude by overcoming stray field effects.
• Optimizing magnetic field conditions is crucial for maximizing coherence times and signal retrieval in EIT-based systems.