Harmonic generation from free electrons in intense laser fields: classical versus semi-classical theory

Abstract

In this paper, a detailed numerical comparison of the high-harmonic generation (HHG) from free electrons in intense laser fields in both classical and semi-classical frameworks has been presented. These two frameworks have been widely used in the literature. It has been found that the HHG spectra display distinct quantitative differences for high-energy electrons. In some special situations, qualitative differences appear. Even if the radiation reaction is included in the electron classical dynamics, no consistent result can be obtained. Hence it should be of critical importance to submit the present HHG theory for high-precision experimental tests, which can help us not only to justify the present theories, but also to check the QED predictions in the high-intensity regime.

Radiation reaction induced harmonics generation in ultra-relativistic intense laser interaction with plasmas

“…By using classical or semiclassical theory, Li et al have investigated high harmonics generation from free electrons interacting with intense laser fields, where the Landau-Lifshitz equation is used to describe the radiation reaction. The frequency shift and the angular power distribution were studied in detail [24]. In the electron-laser head-on Thomason scattering configuration, Ruijter et al have proposed an analytical explanation for the harmonic spectral broadening due to RR effects [25].…”