A superradiant laser is a laser that does not rely on a large population of photons within the laser cavity to maintain coherence.
[1][2] Rather than relying on photons to store phase coherence, it relies on collective effects in an atomic medium to store coherence.
Such a laser uses repumped Dicke superradiance (or superfluorescence) to sustain emission of light that can have a substantially narrower linewidth than a conventional laser.
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