Theory of the crossover from lasing to steady state superradiance

Understand

Lasing and steady state superradiance are two phenomena that may appear at first glance to be distinct.

• In a laser, phase information is maintained by a macroscopic intracavity light field, and the robustness of this phase is what leads to the coherence of the output light.
• In contrast, the coherence of steady-state superradiant systems derives from the macroscopic collective dipole of a many-atom ensemble.
• In this paper, we develop a quantum theory that connects smoothly between these two extreme limits.