We report a novel technique for storing digital optical data in coherent time-domain optical memory to circumvent the problem of coherent saturation. In this technique, the carrier frequency of a data stream to be stored is slowly chirped so its power is spread over the data bandwidth for maximum data storage. In a proof-of-concept experiment, a total of 500 bits of data were stored at a rate of 20 Mbits/s in a 45-MHz-wide channel within the inhomogeneous line of the 7F0−5D1 transition in Eu3+:Y2SiO5. The result suggests a minimum storage density of ~1.5 Gbits/cm3 for this transition. Issues related to the storage of frequency-chirped data, such as the optimum chirp width and the saturation owing to peak–sidelobe interference, are also discussed.
© 1993 Optical Society of America
Original Manuscript: June 14, 1993
Published: November 15, 1993
X. A. Shen and R. Kachru, "Coherent saturation removal in time-domain optical memory by storage of frequency-chirped data pulses," Opt. Lett. 18, 1967-1969 (1993)