Micro-pulling down method-grown Er3+:LiCaAlF6 as prospective vacuum ultraviolet laser material

Abstract We report the successful growth of trivalent erbium-doped lithium calcium aluminum fluoride (Er 3+ :LiCaAlF 6 ) using the micro-pulling down method. Several absorption bands were observed at 139 nm (71,942 cm −1 ), 149 nm (67,114 cm −1 ), and 162 nm (61,728 cm −1 ), which can be ascribed to 4 f →5 d transitions in Er 3+ . Evaluation of its optical properties using the 157-nm emission of a F 2 laser reveal that it has a 163-nm vacuum ultraviolet fluorescence with 1.3-μs decay time, involving a transition originating from the high-spin state of the 4 f 10 5 d excited state configuration. This is one of the shortest emission wavelengths from solid-state materials reported at room temperature.