Quantum Orbits Theory of High-Order Harmonic Generation
Abstract
Atoms submitted to strong laser fields can emit electrons and photons of very high energies, due to the highly nonlinear interaction. These complex processes find a highly intuitive and also quantitative explanation in terms of Feynman's path integral and the concept of quantum orbits [1]. In the present contribution high-order harmonic generation by single atoms is considered in the strong-field approximation and analyzed in terms of quantum orbits. Orbits are classified according to the solutions of the saddle-point equations. Very few quantum orbits are necessary to reproduce the spectra of plateau and cutoff harmonics. A larger number of orbits has to be taken into account to explain the low-energy part of the plateau. With the formalism developed the enhancement of harmonic generation near channel closings can be explained [2]. [1] P. Salières et al., Science 292, 902 (2001); W. Becker et al., Adv. At. Mol. Opt. Phys. 48, 35 (2002). [2] D. B. Milošević and W. Becker, Phys. Rev. A 66, 063417 (2002).
- Publication:
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APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 2003
- Bibcode:
- 2003APS..DMP.G3008M