Abstract:
Our recent theoretical studies of generation of ultrashort pulses based on collective spontaneous emission from a thin resonant medium layer excited by a pair of high-frequency (compared to the transition frequency of the medium) pulses are reviewed. The source of generated radiation is a resonant polarization pulse in the medium (“stopped polarization pulse”), which is excited and switched off by a pair of light pump pulses. This method allows obtaining attosecond pulses in the optical and ultraviolet ranges, as well as femtosecond terahertz pulses. The effect of the superradiance in generation is discussed. The use of coherent and collective processes makes it possible to achieve a high efficiency of the generation of terahertz radiation. The proposed method is an alternative method of obtaining ultrashort pulses compared to the currently well-developed methods such as the high-harmonic generation method.
The study of the possibility of generating terahertz pulses using diffraction optical elements and superradiance in a three-level medium, as well as the possibility of generating attosecond pulses in hydrogen, was supported by the Russian Science Foundation, project no. 17-19-01097-P. Studies of the possibility of obtaining attosecond pulses in helium and terahertz pulses in a thin film of a nonlinear medium (Fig. 3) were supported by the Russian Foundation for Basic Research, project no. 20-32-70049. The study of applications of unipolar light in optics was supported by the Russian Foundation for Basic Research, project no. 19-02-00312. M.V. Arkhipov acknowledges the support of the Russian Foundation for Basic Research (project no. 20-02-00872 A).
Citation:
R. M. Arkhipov, M. V. Arkhipov, A. V. Pakhomov, M. O. Zhukova, A. N. Tcypkin, N. N. Rosanov, “Generation of ultrashort attosecond and terahertz pulses based on the collective spontaneous emission from a thin resonant medium (brief review)”, Pis'ma v Zh. Èksper. Teoret. Fiz., 113:4 (2021), 237–247; JETP Letters, 113:4 (2021), 242–251