Exploring Structure-Sensitive Factors Relevant to Cryogenic Laser Operation in Oxide Crystals Doped with Er 3+ Ions.

Crystals of GdAlGaO:Er, (LuGd)SiO:Er and LiNbO:Er compounds differing in origin and the nature of their inherent structural disorder were crystalized. Optical absorption and luminescence spectra for transitions between the I and the I multiplets of Er ions for the crystal samples were recorded versus temperatures in the region of 80-300 K. Gathered data were analyzed thoroughly providing the in-depth knowledge of the effects of temperature on intensities, wavelengths and bandwidths of Er transitions. The information acquired together with the knowledge of significant structural dissimilarities of the host crystals chosen made it possible to propose an interpretation of the impact of a structural disorder in Er-doped crystals on their spectroscopic properties, and to determine their lasing ability at cryogenic temperatures upon resonant (in-band) optical pumping.