Slow light using spectral hole burning in a Tm3+:YAG crystal

TL;DR

This paper demonstrates slow light in a Tm3+:YAG crystal using spectral hole burning, avoiding the need for strong coupling fields and highlighting the role of off-resonance atoms in information transfer.

Contribution

It introduces a method for slow light using spectral hole burning in a rare earth doped crystal without requiring simultaneous strong coupling fields.

Findings

Slow light achieved via spectral hole burning in Tm3+:YAG.

No need for strong coupling fields during signal propagation.

Off-resonance atoms carry most of the information during pulse confinement.

Abstract

We report on light slowing down in a rare earth ion doped crystal by persistent spectral hole burning. The absence of motion of the active ions, the large inhomogeneous broadening, the small homogeneous width and the long lifetime of the hyperfine shelving states make this material convenient for the burning of narrow persistent spectral holes. Since the hole can be burnt long before the arrival of the input signal, there is no need for a strong coupling field, illuminating the sample simultaneously with the input signal, in contrast with procedures such as Electromagnetically Induced Transparency or Coherent Population Oscillations. Analyzing the slowing down process, we point out the role played by off resonance atoms where most of the incoming information is carried over while the pulse is confined within the sample.