On the operation of a tunable electromagnetic detector for gravitational waves

The interaction of a gravitational wave with an oscillating EM field inside a detector is analysed in the frame in which the detector's walls are at rest. The interaction is described in terms of a time-dependent dielectric tensor and the energy transfer is derived from a generalised Poynting theorem. The energy transfer is maximum when the GW frequency matches one of the frequencies of quadrupole moment of the EM field. Provided the Q-value of the detector is sufficiently high this method seems particularly suitable for observing GWs emitted by periodic sources.