Diode-pumped cascade Tm:YAG laser at ∼2 μm and ∼2.3 μm

Abstract

We report on the first cascade continuous-wave operation of the Tm:YAG crystals with different doping concentrations (2 at.% Tm:YAG and 3.5 at.% Tm:YAG) on the 3F4 → 3H6 (at ∼2 μm) and 3H4 → 3H5 (at ∼2.3 μm) transitions. With the lower concentration of Tm-doped YAG, the cascade laser generated a maximum total output power of 4.70 W with a higher slope efficiency of 23.9 %, out of which 0.79 W are obtained based on the 3H4 → 3H5 transition at ∼2.3 μm. Such laser that combing the two emission wavelengths makes it has potential application in some special field, e.g., gas detection.