OPTICAL RF DOUBLE RESONANCES IN YLIF4-HO3+

In this paper, double resonance signals associated with CW spectral ho leburning measurements of unintentional Ho3+ impurities in crystals of YLiF4 are reported. The double resonance signals are detected in the microwave and radiofrequency region, The observed microwave resonances are at 4.460(1) and 4.473(1) GHz and attributed to ground state hyper fine splittings. Two radiofrequency resonances at 29.85(8) and 36.86(8 ) MHz are also detected and assigned to superhyperfine transitions of the two inequivalent fluorine nn sites. This assignment is supported b y Zeeman measurements.