Demonstration of room-temperature laser action at 25 µm from Cr^2+:Cd_085Mn_015Te

Room-temperature laser action from Cr²⁺-doped Cd_0.85Mn_0.15Te has been demonstrated for what is believed to be the first time. We achieved pulsed laser operation centered at $\sim 2.5 \mathit{\mu }\mathrm{m}$ by pumping into the mid-infrared absorption band of Cr ²⁺ ions by use of the 1.907-$\mathit{\mu }\mathrm{m}$ output of a H₂ Raman-shifted Nd:YAG laser. The output of the free-running Cr²⁺:Cd_0.85 Mn_0.15Te laser had a width of $\sim 50$ nm (FWHM), and the slope efficiency was calculated to be 5.5% under nonoptimum conditions.