YbF3-doped and NaF co-doped calcium fluoride crystals were grown using the Vertical Bridgman method. Transparent colorless crystals were obtained in graphite crucible in vacuum (≈10−1 Pa) using a shaped graphite furnace. Room temperature absorption spectra and dielectric spectra were measured to study the effect of Na+ ions on the varieties of Yb3+ sites in CaF2 host. The experimental results show that by co-doping with Na+ ions in different Na:Yb ratios we can modulate the type of charge compensating defects of Yb3+ ions in CaF2 lattice. Dielectric relaxation in double doped (Yb, Na):CaF2 crystals-related with the study the charge compensating defects-was not reported before.