Q-switching
/ˌkjuːˈswɪtʃɪŋ/Physics
noun
The process of pumping a laser that has a low Q, and so cannot oscillate, and then suddenly increasing the Q so that the stored energy is released in a single pulse of very high power; the use of a Q-switch.
Origin
1960s; earliest use found in Journal of Applied Physics. Partly from Q + switching, and partly from either Q-switch or Q-switch + -ing.