Nb. Manson et al., HOLE-BURNING AND OPTICAL RF DOUBLE-RESONANCE STUDIES OF TRIGONAL HO3+CENTERS IN CAF2, Journal of luminescence, 64(1-6), 1995, pp. 39-43
Two laser hole burning in a transition of trigonal Ho3+ centers in CaF
2 with resolved narrow hyperfine structure is reported. Associated dou
ble resonances give superhyperfine frequencies that are sensitive to t
he holmium orbital and nuclear states.