We report an observation of a delayed all-optical routing/switching
phenomenon based on ultraslow group velocity of light via nondegenerate
four-wave mixing processes in a defected solid medium. Unlike previous
demonstrations of enhanced four-wave mixing processes using the slow light
effects, the present observation demonstrates a direct retrieval of the
resonant Raman-pulse excited spin coherence into photon coherence through
coherence conversion processes.Comment: 5 pages with 3 figures include