Total polarization conversion in a two-dimensional electron system under cyclotron polariton resonance conditions

The polarization conversion of a linear polarized electromagnetic wave incident onto a two-dimensional (2D) electron system at an angle θ is theoretically studied. We consider the 2D system located at the interface between two dielectric media with different dielectric constants. An external dc magnetic field is assumed to be directed along the normal to the 2D electron layer. In such a configuration the cyclotron polaritons (CPs) in the 2D electron system can be excited with frequencies in the vicinity of the cyclotron frequency. Under the CP excitation the resonance polarization conversion of the electromagnetic wave greatly increases in the system. In the absence of electron scattering in the 2D system, the polarization conversion reaches 100% at a certain value of the angle of incidence θ>θR, where θR is the total reflection angle. Extremely high polarization conversion takes place in a quite wide range of variation of the angle of incidence. High polarization conversion efficiency (above 80%) remains when the actual electron scattering in the 2D system on GsAs is taken into account. The considered phenomena may be taken up in polarization spectroscopy of 2D electron systems.