Broad-band polarization-independent total absorption of electromagnetic waves by an overdense plasma

摘要

We have shown both experimentally and theoretically thatpolarization-independent broad-band absorption of electromagnetic waves by anoverdense plasma, caused by surface plasmon-polaritons (SPP) excitation, can beachieved due to combination of two factors: a non-zero angle of incidence and atwo-dimensional circular diffraction grating placed at a properly chosendistance in front of the plasma boundary. Direct detection of SPP has beenachieved for the first time using a miniature antenna imbedded in the plasma.