Lasing without inversion (LWI), or lasing without population inversion, is a technique used for
light amplification by stimulated emission without the requirement of
population inversion. A laser working under this scheme exploits the
quantum interference between the probability amplitudes of atomic transitions in order to eliminate absorption without disturbing the
stimulated emission
Stimulated emission is the process by which an incoming photon of a specific frequency can interact with an excited atomic electron (or other excited molecular state), causing it to drop to a lower energy level. The liberated energy transfers to ...
. This phenomenon is also the essence of
electromagnetically induced transparency.
The basic LWI concept was first predicted by
Ali Javan in 1956. The first demonstration of LWI was carried out by
Marlan Scully
Marlan Orvil Scully (born August 3, 1939) is an American physicist best known for his work in theoretical quantum optics. He is a professor at Texas A&M University and Princeton University. Additionally, in 2012 he developed a lab at the Baylor ...
in an experiment in rubidium and sodium at Texas A&M University, and then at NIST in Boulder.
[Javan, A. (2000). "On knowing Marlan". In ''Ode to a quantum physicist: A festschrift in honor of Marlan O. Scully''. Elsevier.]
References
Quantum optics
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