An electromagnetic detector for very-high-frequency gravitational waves

An interaction between a gravitational wave and the polarization vector of an electromagnetic wave is described in which the polarization vector rotates about the direction of propagation. If a resonant condition can be established with the electromagnetic wave always experiencing the same phase of the gravitational wave then the effect is cumulative and can be enhanced linearly by repeated circuits of a closed loop. When implemented with realistic experimental apparatus, a detector sensitive to gravitational waves at very high frequencies can be envisaged, in a frequency range where the signals are expected to be from cosmological sources at very early moments in the Universe.