Spectrally ordered Zeeman coherences and optical pulse-shape storage

Abstract

We have experimentally investigated the creation of spectrally ordered nuclear and electronic Zeeman coherences in a gas-phase sample. A Zeeman coherence is generated through the sequential excitation of two coupled optical transitions. In our experiment, one transition was excited by a data pulse and the other by a short reference pulse. Subsequent excitation of one of these transitions by a short reading pulse transforms the Zeeman coherence into an optical coherence and leads to the emission of a time-forward or time-reversed duplicate of the data pulse. Output signals up to 5% as intense as the original data pulse were observed. We present a general analysis that is applicable to both gases and solids and find that the solid-state analog of this process will exist only if the inhomogeneous broadening of the two optical transitions is highly correlated.