Frontiers of mid-infrared lasers based on transition metal doped II–VI semiconductors

Recent progress in chromium and iron doped II–VI semiconductor materials makes them the laser sources of choice when one needs a compact system with broad mid-IR tunability over 1.9–6 μm. Output powers exceeding 10 W, output energies 20 mJ, pulse durations 80 fs, peak powers in excess of 1 GW, and efficiency up to 70% were demonstrated in several Cr doped semiconductors. The unique combination of technological and spectroscopic characteristics makes these materials ideal candidates for mid-IR tunable and ultrafast laser systems. This article reviews transition metal doped II–VI materials and recent progress in Cr- and Fe- doped solid-state mid-IR lasers.