Mid-Infrared Laser Generation of Zn1-xMnxSe and Zn1-xMgxSe (x ≈ 0.3) Single Crystals Co-Doped by Cr2+ and Fe2+ Ions-Comparison of Different Excitation Wavelengths

Two different mid-infrared (mid-IR) solid-state crystalline laser active media of Cr2+, Fe2+:Zn1-xMnxSe and Cr2+, Fe2+:Zn1-xMgxSe with similar amounts of manganese or magnesium ions of x 0.3 were investigated at cryogenic temperatures for three different excitation wavelengths: Q-switched Er:YLF laser at the wavelength of 1.73 mu m, Q-switched Er:YAG laser at 2.94 mu m, and the gain-switched Fe:ZnSe laser operated at a liquid nitrogen temperature of 78 K at similar to 4.05 mu m. The temperature dependence of spectral and laser characteristics was measured. Depending on the excitation wavelength and the selected output coupler, both laser systems were able to generate radiation by Cr2+ or by Fe2+ ions under direct excitation or indirectly by the Cr2+ -> Fe2+ energy transfer mechanism. Laser generation of Fe2+ ions in Cr2+, Fe2+:Zn1-xMgxSe and Cr2+, Fe2+:Zn1-xMgxSe (x approximate to 0.3) crystals at the wavelengths of similar to 4.4 and similar to 4.8 mu m at a temperature of 78 K was achieved, respectively. The excitation of Fe2+ ions in both samples by direct 2.94 mu m as well as similar to 4.05 mu m radiation or indirectly via the Cr2+ -> Fe2+ ions' energy transfer-based mechanism by 1.73 mu m radiation was demonstrated. Based on the obtained results, the possibility of developing novel coherent laser systems in mid-IR regions (similar to 2.3-2.5 and similar to 4.4-4.9 mu m) based on A(II)B(VI) matrices was presented.