A 7-/spl mu/m praseodymium-based solid-state laser

We report the first demonstration of laser emission from the /sup 3/F/sub 3/ to /sup 3/F/sub 2/ transition in the rare earth praseodymium. This new 7-/spl mu/m solid-state laser operates with an optical efficiency of 2.3% at 293 K and 10% at 150 K using an upconversion pumping mechanism. A discussion of the dynamics in this new laser material is included.