Tunable in the range of 4.5-6.8 µm room temperature single-crystal Fe:CdTe laser pumped by Fe:ZnSe laser

We report a laser operation from a Fe:CdTe single crystal, pumped by 40-ns pulses of a 4.12-µm Fe:ZnSe laser. The maximum output energy of 5.8 mJ was produced at 5.4 µm with 30% absorbed energy slope efficiency. A record 2300-nm-wide smooth and continuous wavelength tunability over 4.5-6.8 µm range was demonstrated, being the longest wavelength tuning achieved for Fe²⁺-doped chalcogenide lasers. We also discuss the features of the oscillation spectra.