Photon-echo nuclear double resonance in LaF3:Pr3+

Abstract
Using the photon-echo-nuclear-double-resonance technique, we have measured the nuclear hyperfine splittings in the excited D21 state of LaF3:Pr3+. Our measurements are in agreement with the results obtained by Erickson from his saturated-and-enhanced-absorption study of the H43D21 transition in LaF3:Pr3+.