We propose a scheme for robust writing and storage of optical phase information in populations of metastable states of the atoms with a tripod structure of levels by using frequency-chirped laser pulses. The method provides much longer storage times compared with the schemes based on the collective atomic spin coherences. A negligible excitation of the atom provides immunity to decoherence induced by decay of the excited states. The method is robust against small-to-medium variations in the laser pulse intensity and speed of the chirp and, being insensitive to resonance conditions, it is effective both in homogeneously and inhomogeneously broadened media.
© 2009 Optical Society of America
Optical Data Storage
Original Manuscript: March 12, 2009
Revised Manuscript: June 29, 2009
Published: September 25, 2009
G. P. Djotyan, N. Sandor, J. S. Bakos, and Zs. Sörlei, "Optical phase information writing and storage in populations of metastable quantum states," J. Opt. Soc. Am. B 26, 1959-1966 (2009)