superradiant laser

A superradiant laser is a laser that does not rely on a large population of photons within the laser cavity to maintain coherence.{{cite web|url=http://physicsworld.com/cws/article/news/2012/apr/05/superradiant-laser-created-for-first-time|title='Superradiant' laser created for first time|date=Apr 5, 2012|publisher=physicsworld.com}}{{cite web|url=https://www.sciencedaily.com/releases/2012/04/120404133654.htm|title=New Way of Lasing: A 'Superradiant' Laser|publisher=Science Daily|date=April 4, 2012}}

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.{{cite journal|url=http://link.aps.org/doi/10.1103/PhysRevLett.102.163601|title=Prospects for a Millihertz-Linewidth Laser | doi=10.1103/PhysRevLett.102.163601 | bibcode=2009PhRvL.102p3601M|volume=102|journal=Physical Review Letters | last1 = Meiser | first1 = D.|arxiv=0901.3105}}