LIGHT SHIFTS OF SHARP LINES IN RE-DOPED SOLIDS

We examine the possibility of observing shifts of the 4f levels of tri valent rare-earth ions in an ionic solid due to a nonresonant electrom agnetic field. For the case of Pr-doped LaF3, we show that shifts on t he order of tens of MHz can easily be generated, and we propose an exp eriment to observe them.