It is shown that simultaneous and spatially overlapping multiple photon echoes can occur following application of a single optical pulse followed by multiple pairs of counterpropagating pulses in various directions—degenerate photon echoes. This scheme has been experimentally verified in Pr3+:LaF3 for the doubly degenerate case. In the small-pulse-area regime, the two echoes are observed to be independent with no cross talk between them. From the viewpoint of transient optical memory, this enables us to store multiple independent optical data in one sample spot and to retrieve any one of them, thereby multiplying the memory capacity of the crystal.
© 1988 Optical Society of America
Original Manuscript: January 5, 1988
Manuscript Accepted: March 10, 1988
Published: June 1, 1988
M. Mitsunaga, M. K. Kim, and R. Kachru, "Degenerate photon echoes: simultaneous storage of multiple optical data," Opt. Lett. 13, 536-538 (1988)