Cascade lasing at ∼2 μm and ∼2.3 μm in a diode-pumped Tm:YVO₄ laser

We report on the cascade continuous-wave operation of a diode-pumped Tm:YVO₄ laser on the ³F₄ → ³H₆ (at ∼2 μm) and ³H₄ → ³H₅ (at ∼2.3 μm) Tm³⁺ transitions. Pumped with a fiber-coupled spatially multimode 794 nm AlGaAs laser diode, the 1.5 at.% Tm:YVO₄ laser yielded a maximum total output power of 6.09 W with a slope efficiency of 35.7% out of which the ³H₄ → ³H₅ laser emission corresponded to 1.15 W at 2291-2295 and 2362-2371 nm with a slope efficiency of 7.9% and a laser threshold of 6.25 W.