Efficient tunable LiF:F2 crystal lasers containing F2 and F2+ color centers

Optimization of the technology of fabrication of active LiF (F₂→F₂⁺) laser elements operating at room temperature ensured high parameters of broad-band emission of light by the F₂ and F₂⁺ color centers in a nonselective resonator pumped by the second harmonic of a pulse-periodic YAG:Nd³⁺ laser (λ = 0.532 μm). The efficiency of the LiF (F₂→F₂⁺) laser, expressed in terms of the pumping, was 38%, whereas in terms of the absorbed energy it was 41%. The service life of one pump channel of the LiF (F₂→F₂⁺) laser exceeded 5 × 10⁵ pulses when the pump radiation power density was 150 MW/cm² and the diameter of the active channel was d = 1.5 mm. Broad-band lasing of the F₂ color centers in the same system, but without focusing of the pump radiation, was observed for a period of 15 min at a pulse repetition frequency 12.5 Hz when the pump power density was 40 MW/cm².