Fe 2+ -doped CdSe single crystal: growth, spectroscopic and laser properties, potential use as a 6 µ m broadband amplifier

We report on the successful growth of single crystals of Fe 2+ :CdSe by seeded physical vapor transport (SPVT) technique with doping within the growing process and subsequent annealing in Se vapor. Luminescence lifetime measurements, spectroscopic studies of 5 E– 5 T 2 transition of Fe 2+ in CdSe, and laser experiments were performed. The lifetime of the 5 T 2 energy level was measured to be 20 ± 5 ns at a room temperature (RT) of 290 K. At liquid nitrogen (LN) temperature, luminescence kinetics displayed a non-exponential decay, which can be fitted to a bi-exponential function with time constants τ 1 = 6 µ s and τ 2 = 29 µ s. As much as 3.2 mJ of output energy at 5.2 µ m with 27% absorbed pump energy slope efficiency of an Fe 2+ :CdSe laser was achieved at RT under 2.94 µ m nanosecond Er:YAG laser pumping. The Fe 2+ :CdSe laser was tuned from 4.63 to 6.10 µ m. Obtained characteristics of Fe 2+ :CdSe indicate that the crystal can be considered a promising medium for amplification of femtosecond pulses in the middle infrared range up to 6 µ m.