Генерация Аттосекундного Импульса На Основе Коллективного Спонтанного Излучения Слоя Трехуровневых Атомов, Возбуждаемых Парой Униполярных Импульсов

Abstract

Recently, for the generation of extremely short pulses, a method was proposed for coherent control of the polarization of a medium, based on the excitation of atomic polarization oscillations and their subsequent arrest using a pair of ultra short pulses. The so-called stopped pulse of polarization of the medium, which appears in the interval between its excitation and de-excitation, can be a source of an extremely short radiation pulse. In this paper, the indicated possibility of generating an isolated attosecond ultraviolet pulse in a three-level resonant medium, the parameters of which correspond to a hydrogen atom excited by a pair of unipolar X-ray pulses, is considered theoretically. In this case, the generation mechanism is "antenna", that is, it is caused by the collective spontaneous emission of pre-phased atoms in the absence of a noticeable decay of their free polarization. Key words: collective spontaneous emission, coherent control of atomic polarization, attosecond pulses, unipolar pulses, X-ray pulses, hydrogen atom.