Word-by-word logical AND and OR operation with photon-echo processing
is demonstrated for what is to our knowledge the first time. The photo
n-echo process can store sequences of optical data before processing.
The present logical operations on 8- and 4-bit words are performed by
using single-shot frequency-chirped photon echoes. Data rates of appro
ximately 1 MHz, input energies of 1-10 nJ/bit, and output energies in
the picojoule-per-bit range are demonstrated by using a transition wit
h a transition probability of only 20 s(-1).