Population Inversion Induced by Collisions in a Two Level System under Nonresonance Optical Excitation

Autor:	A. M. Shalagin, Alexander I. Plekhanov, R. V. Markov
Rok vydání:	2002
Předmět:	Physics Thermal reservoir Einstein coefficients Buffer gas Quantum system General Physics and Astronomy Atomic physics Population inversion Lasing threshold Resonance (particle physics) Excitation
Zdroj:	Physical Review Letters. 88
ISSN:	1079-7114 0031-9007
Popis:	When the gas particles, which can be considered as a two level quantum system, are affected by frequent collisions with buffer gas particles (thermal reservoir), the spectral densities of the Einstein coefficients for absorption and induced emission are unequal to each other far from the absorption (emission) line. The relationship between the spectral densities at the specified condition reveals new physical phenomena. The mostly convincing example is the fact that population inversion is established in a two level system under nonresonance optical excitation. This effect is experimentally observed as a lasing on sodium resonance transitions.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8b30fd3b549493bdf80d958dbb17be05 https://doi.org/10.1103/physrevlett.88.213601 Zobrazit plný text záznamu