Polarization of the Radiation Emitted in GaAs Semiconductors Driven by Far Infrared Fields

The effects due to the mixing of two far infrared electric fields on the harmonic generation process in low doped GaAs bulks are studied by a three dimensional multivalleys Monte Carlo simulation. The conversion efficiency is calculated by using the appropriate Maxwell equation for the propagation of an electro-magnetic wave along a given direction in the medium. In particular, we focus our attention on the polarization of the generated harmonics, by comparing the polarization obtained from the mixing of an oscillating field with a static electric field with that obtained in the presence of two cyclostationary fields, having an integer ratio between the two frequencies. The findings show that the strength and the polarization of the mixed fields emission exhibit a strong dependence on the angle between the orientation of the two fields. Unusual polarization features of the generated harmonics have been found and discussed.