Effects of atomic coherence on multi-level lasing systems
The author begins with a discussion of the semiclassical effects of atomic coherence on driven atoms. The author discusses the presence of a simultaneous population inversion in two pairs of a doubly driven three level atom and propose a new method for the indirect measurement of a weak decay rate by coupling it to a strong transition. The author then describe a semiclassical laser with an active medium of driven atoms in the cascade configuration. In this configuration, the external driving field and the laser field share a common interaction level. The author considers two possibilities of incoherent decay; one in which the decay takes place among the coherently coupled levels (a closed system) and the other in which the decay occurs only to a lower lying level removed from the coherent interactions (an open system). Both configurations present the interesting effect of a decrease in gain and steady state intensity as the strength of the external driving field is increased. The author calls this coherent quenching and shows it is the result of quantum interferences. Finally, the author concludes with a discussion of the quantum theory of driven cascade and lambda atoms. THe author derives the master equation and presents results on the transient and steady state solutions of the density matrix and its moments such as average number of photons and variance. Among the results, is the appearance of a sub-Poissonian photon number distribution. The author concludes with a discussion of the linewidth and fluctuation properties of this laser.
- Research Organization:
- Drexel Univ., Philadelphia, PA (United States)
- OSTI ID:
- 7073604
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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