Quantum theory of optical-pulse propagation through an amplifying slab

7 págs.; 6 figs.; PACS number: 42.50.2pWe calculate the effects of normal transmission through an amplifying dielectric slab on the properties of an incident pulse of light. The transmitted pulse shows shifts in peak position and additional lengthening or shortening with respect to the unamplified incident pulse. The magnitudes of these effects are generally larger than those of the corresponding changes that occur in transparent or attenuating slabs. They are interpreted in terms of the interference of multiply reflected contributions to the transmitted pulse. The theory is valid for pulses of nonclassical light, but the same reshaping occurs for appropriate pulses of classical light. ©1998 American Physical SocietyWe thank the European Community Human Capital and Mobility Programme and the Ministerio de Educacion y Cultura of Spain for financial support.Peer Reviewe