Population hole burning on the 4f(7)(S-8(7/2)) to 4f(6)5d zero-phonon transition in crystalline SrF2 : EU2+

Transient spectral holes due to the redistribution of population among the ground-state hyperfine levels have been detected on the 401 nm zero-phonon transition of Eu-2 (+) in an SrF2 crystal. The hole profile consists of a n arrow central hole ( similar to 80 MHz) and a pattern of side holes and ant iholes determined by the hyperfine splittings in both the ground and excite d states. The hole spectrum is accompanied by strong and narrow (similar to 33 MHz at 1.5 K) nuclear spin-flip side holes associated with an F nuclear spin flip. Magnetic (up to 6.5 T) and temperature (1.5-3.8 K) studies reve al rapid relaxation among strongly coupled and closely spaced vibronic Jahn -Teller levels. The observed broadening of the hole line width as the burni ng frequency is tuned to the high-energy side of the inhomogenously broaden ed line is consistent with rapid relaxation among these states. (C) 1999 El sevier Science B.V. All rights reserved.