Excitation and temperature dependence of the image manifolds emission in image single crystal

A spectroscopic investigation on KYF4:1.25 at.% Pr3+ is presented, we report in detail on the effects of the multisite-disordered nature of the sample on its optical properties. In particular we discuss the broadening of the image absorption lines, at room temperature, and the 570–665 nm orange-red polarized emissions pumping the image and image manifolds at 445 and 457 nm, respectively. The image lifetime was in agreement with that measured in other fluoride hosts. Moreover we present the unpolarized emission as a function of temperature (300–700 K) which also allows an evaluation of KYF4 phonon energy around 350 cm−1.