Editing Lasing threshold (section)

The '''lasing threshold''' is the lowest excitation level at which a [[laser|laser's]] output is dominated by [[stimulated emission]] rather than by [[spontaneous emission]]. Below the threshold, the laser's output power rises slowly with increasing [[laser pumping|excitation]]. Above threshold, the slope of power vs. excitation is [[Order of magnitude|orders of magnitude]] greater. The [[linewidth]] of the laser's emission also becomes orders of magnitude smaller above the threshold than it is below. Above the threshold, the laser is said to be ''lasing''. The term "lasing" is a [[back formation]] from "laser," which is an [[acronym]], not an [[agent noun]].