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.

Abstract

Two different mid-infrared (mid-IR) solid-state crystalline laser active media of Cr, Fe:ZnMnSe and Cr, Fe:ZnMgSe 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 m, Q-switched Er:YAG laser at 2.94 m, and the gain-switched Fe:ZnSe laser operated at a liquid nitrogen temperature of 78 K at ∼4.05 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 Cr or by Fe ions under direct excitation or indirectly by the Cr→ Fe energy transfer mechanism. Laser generation of Fe ions in Cr, Fe:ZnMnSe and Cr, Fe:ZnMgSe (x ≈ 0.3) crystals at the wavelengths of ∼4.4 and ∼4.8 m at a temperature of 78 K was achieved, respectively. The excitation of Fe ions in both samples by direct 2.94 m as well as ∼4.05 m radiation or indirectly via the Cr→ Fe ions’ energy transfer-based mechanism by 1.73 m radiation was demonstrated. Based on the obtained results, the possibility of developing novel coherent laser systems in mid-IR regions (∼2.3–2.5 and ∼4.4–4.9 m) based on AB matrices was presented.