[en] Laser excitation studies of CaF₂ crystals doped with 0.01 to 10% Ho³⁺ using the second harmonic wavelength 532 nm of a pulsed Nd:YAG laser are carried out. Three fluorescence bands belonging to the ⁵F₄, ⁵S₂ → ⁵I₈, ⁵F₄, ⁵S₂ → ⁵I₇ and ⁵F₅ → ⁵I₈ transitions are detected. Fluorescence lifetimes of the first two transitions are measured and used for site-identification of new lines. Four upconverted fluorescence bands belonging to the ⁵F₃ → ⁵I₈, ⁵G₄ → ⁵I₈, ⁵G₅ → ⁵I₈, ⁵H₅, ⁵H₆ → ⁵I₈ transitions are also detected. A comparative study is made of two pairs of energy transfer mechanisms, which are multiphonon relaxation versus ion-pair relaxation and two-photon absorption versus ion-pair relaxation. The analysis of the concentration dependence of fluorescence intensities shows that ion-pair relaxation is the chief mechanism responsible for the fluorescence and upconversion behaviour of CaF₂:Ho³⁺. (orig.)