Abstract

Already at the beginning of the laser era it was shown that Dy²⁺:CaF₂ lasers could be use as direct radiation sources in spectral range 2.4 µm. [1] Since the Dy²⁺ upper laser level is strongly temperature quenched, cryogenic cooling of Dy²⁺:CaF₂ laser is necessary to reach efficient lasing. Thanks to long upper laser level lifetime an effective pump energy accumulation is possible and therefore the generation of 20 ns Q-switched pulses with peak power 0.5 MW was reached using Dy²⁺:CaF₂ laser. [2] Very narrow fluorescent linewidth 0.3 cm⁻¹ at 77 K [1] of Dy²⁺:CaF₂ limits the shortest generated pulse length to approximately 100 ps. In the Dy²⁺:CaF₂ crystal there are broad absorption bands in visible and near-infrared regions thus a common available laser diodes are suitable for pumping. In this work we report the first diode-pumped Dy²⁺:CaF₂ laser results.

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