Measurement of photon echoes in Er: Y₂SiO₅ at 1.5 μm with a diode laser and an amplifier

We have measured the optical dephasing time of Er3+ transitions near 1.5 μm in the two crystallographically inequivalent sites of Y2SiO5, using an external-cavity diode laser amplified by an erbium-doped fiber amplifier. Two-pulse photon echoes were observed at zero field and in magnetic fields up to 55 kG, with dephasing times as long as 580 μs (corresponding to a linewidth of 550 Hz). Stimulated echoes were also measured and showed evidence of spectral diffusion during the 13-ms lifetime of the 4/13/2 level. © 1997 Optical Society of America.