Triggered superradiance
Christoph H. Keitel, Marlan O. Scully, Georg Süssmann · Physical Review A · 1992
By applying microwave pulses to the two lower levels of three-level atoms in the ssV configuration, the collective state vector can be switched from forbidden to allowed transitions. This means that we can, in effect, switch the superradiant and subradiant processes from off to on and vice versa.