Open AccessHarmonic generation beyond the Strong-Field Approximation: the physics behind the short-wave-infrared scaling laws
Author(s) -
J. A. Pérez-Hernández,
L. Roso,
Luis Plaja
Publication year - 2009
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.009891
Subject(s) - physics , high harmonic generation , extreme ultraviolet , field (mathematics) , attosecond , nonlinear optics , harmonic , optics , infrared , wavelength , scaling , laser , quantum mechanics , quantum electrodynamics , mathematics , pure mathematics , ultrashort pulse , geometry
The physics of laser-mater interactions beyond the perturbative limit configures the field of extreme non-linear optics. Although most experiments have been done in the near infrared ( lambda <or= 1 microm), the situation is changing nowadays with the development of sources at longer wavelengths (<5 microm), opening new perspectives in the synthesis of shorter XUV attosecond pulses and higher frequencies. The theory of intense-field interactions is based either on the exact numerical integration of the time-dependent Schrödinger equation or in the development of models, mostly based on the strong-field approximation. Recent studies in the short-wave infrared show a divergence between the predictions of these models and the exact results. In this paper we will show that this discrepancy reveals the incompleteness of our present understanding of high-order harmonic generation. We discuss the physical grounds, provide a theoretical framework beyond the standard approximations and develop a compact approach that accounts for the correct scaling of the harmonic yield.