For 10 points, name these devices that use stimulated emission to emit amplified light.
These devices can be modified to produce a pulsed output by varying the Q-factor in the resonator. These devices require a gain medium to add energy to the output. In these devices, pumping is used to convert the majority of the atoms to an excited state to combat the effects of absorption - that state is called population inversion. The basic premise of these devices is that a photon interacts with an electron in an excited state to knock it down to the ground state, producing two photons, causing a cascade that generates a large number of photons of the same wavelength. For 10 points, name these devices that use stimulated emission to emit amplified light.
These devices can be modified to produce a pulsed output by varying the Q-factor in the resonator.
lasers [the acronym is "light amplification by stimulated emission of radiation"]