Abstract

This work is concerned with the comparative characterization of two low-phonon laser gain materials based on Dysprosium (Dy) doped Potassium Lead Chloride (KPC) and Lead Thiogallate (PGS). The laser performance of both crystals emitting near 4.4 μm and 4.6 μm respectively was investigated for cw and quasi-cw pumping. Furthermore, the power as well as emission/tuning performance was studies under normal atmosphere or for an N₂-purged laser resonator to minimize water and CO₂ absorption. Useful application fields for such lasers emitting in the mid-IR are anticipated to be “differential absorption LIDAR” (DIAL) of atmospheric greenhouse gases (GHG) and “ranged finding” in defense sector. These applications utilize the presence of many strong molecular absorption lines as well as low water absorption windows, in this spectral range, but also the reduced light scatter from dust, mist, fog, and other particulates, when compared to shorter wavelengths. Consecutively, the experimental results were used to estimate expected Q-switched laser performance. This was done to explore realistic pulsed performance with intend to facilitate a laser platform for the prementioned application fields.

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