R.W. Syme, H. Morawitz, et al.
Solid State Communications
Using a low-strain, isotopically pure crystal of YLiF4, we have measured extremely narrow inhomogeneous linewidths (as low as 40 MHz) for the optical transitions of Er3+ impurities. Inhomogeneous broadening due to strains and other defects is so low that a new mechanism limits the inhomogeneous linewidth: local magnetic fields due to fluorine nuclear spins. These ultranarrow lines enabled us to make the first direct measurement of the isotope shifts of f-f transitions in a solid, and we find for the isotopes Er164, Er166, Er168, and Er170 a shift of 76±2 MHz unit mass on the 4I15/2(1)4F9/2(1) transition. We show that this is consistent with a mechanism of coupling to zero-point vibrations. © 1992 The American Physical Society.
R.W. Syme, H. Morawitz, et al.
Solid State Communications
R.M. Macfarlane, W.S. Brocklesby, et al.
Optics Communications
H. Gunther, R.M. Shelby, et al.
CLEO 1997
R.M. Macfarlane, R.M. Shelby
Optics Communications