Physical explanation of noise reduction in the two-photon correlated spontaneous emission laser

Recently a type of correlated emission laser has been proposed in which a cascade transition of three-level atoms is coupled to only one mode of the radiation field. In this two-photon correlation emission laser (CEL) the lasing atoms have a well-defined coherence between the upper (a) and lower (c) level, leading to a correlation between the light emitted by an a b and subsequent b c transition. It has been shown by a Fokker-Planck analysis that such a system can indeed have significant phase noise suppression, but the analysis does not provide a physical picture of the origin of noise reduction. Semiclassical arguments that show in a simple pictorial way how the phase noise can be made to vanish in a two-photon CEL are presented.

Physical explanation of noise reduction in the two-photon correlated spontaneous emission laser Conference Paper