Demonstration of a cw room temperature mid-IR microlaser

We report a demonstration of the first continuous-wave (cw) mid-IR microlaser operating at room temperature (RT). Our whispering-gallery-mode microlaser-operating at 2.71 μm-is based on a heavily erbium-doped high-Q ZBLAN microsphere optically pumped by a 980 nm diode laser; with a threshold pump power of <150  μW.