Spectroscopic evaluations of optical cooling effect in LiNbO3:Yb3+ crystal.

Based on the results obtained from detailed investigations of absorption and luminescence spectra of the LiNbO(3):Yb(3+) crystal the availability of this material for solid-state optical refrigerators is evaluated. Anti-Stokes luminescence registered for this crystal in the wavelength region near the 980 nm under the optical excitation at the 1064 nm allows estimation of main characteristics of the laser cooling effect. Conditions for increasing the efficiency of laser cooling effect in the material under study are discussed. The new approach to measure temperature changes of ferroelectric samples under an optical irradiation is proposed.