MEASUREMENT OF PHOTON-ECHOES IN ER-Y2SIO5 AT 1.5-MU-M WITH A DIODE-LASER AND AN AMPLIFIER

We have measured the optical dephasing time of Er3+ transitions near 1 .5 mu m in the two crystallographically inequivalent sites of Y2SiO5, using an external-cavity diode laser amplified by an erbium-doped fibe r amplifier. Two-pulse photon echoes were observed at zero field and i n magnetic fields up to 55 kG, with dephasing times as long as 580 mu s (corresponding to a linewidth of 550 Hz). Stimulated echoes were als o measured and showed evidence of spectral diffusion during the 13-ms lifetime of the I-4(13/2) level. (C) 1997 Optical Society of America.