Photon-echo measurements are reported for the trivalent thulium ion, which differs from all other rare-earth ions in having a single isotope of nuclear spin 1/2. Echo decays on the 3H6(1) ↔ 3H4(1) transition of LaF3:Tm3+ and YAG:Tm3+ were magnetic-field dependent at 1.5 K, showing that the dephasing originates from spin fluctuations of nuclei in the host crystals. Coherence times in the range of 7 to 100 μs were measured, corresponding to homogeneous linewidths of tens of kilohertz. The echo decays were nonexponential, providing evidence for spectral diffusion that is due to a distribution of 19F and 27A1 nuclear spin-flip times in the respective hosts.
© 1993 Optical Society of America
Original Manuscript: June 10, 1993
Published: November 15, 1993
R. M. Macfarlane, "Photon-echo measurements on the trivalent thulium ion," Opt. Lett. 18, 1958-1960 (1993)