Mid-IR (4–5<i>µ</i>m) femtosecond multipass amplification of optical parametric seed pulse up to gigawatt level in Fe²⁺:ZnSe with optical pumping by a solid-state 3<i>µ</i>m laser

Abstract

We demonstrate a first-of-its-kind efficient amplification of a broadband tunable (from 3.8 to 4.8 µm) mid-IR femtosecond seed pulse generated from a AgGaS2-based optical parametric amplifier pumped by a Cr:forsterite laser in a multi-pass Fe2+:ZnSe amplifier optically pumped by a solid-state nanosecond Cr:Yb:Ho:YSGG laser. A total gain of 2000 for an input seed energy of 40 nJ has been obtained. The magnitude of the output energy reaches 80 µJ at a pulse duration of 200 fs.